Publications by authors named "Meissam Noroozifar"

50 Publications

Experimental and computational interaction studies of terbium (III) and lanthanide (III) complexes containing 2,2'-bipyridine with bovine serum albumin and their anticancer and antimicrobial activities.

J Biomol Struct Dyn 2020 Jul 16:1-12. Epub 2020 Jul 16.

Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON, Canada.

To investigate the chemotherapeutic and pharmacokinetic aspects of two lanthanide complexes (Tb(III) and La(III) containing 2,2'-bipyridine ligand), binding studies were carried out with BSA by employing multiple biophysical methods and molecular modeling study. There are different techniques containing fluorescence, absorption spectroscopy and competitive experiments to determine the interaction mode between BSA and these complexes. These complexes efficiently quenched the BSA emission through a static procedure. The results showed that the terbium and lanthanum complexes exhibited a high propensity for BSA interaction van der Waals force. Further, competitive examination and docking study showed that the interaction site of these complexes on BSA is site III. The results of docking calculations were in good agreement with experimental examinations. Also, the energy transfer from BSA to these complexes has happened with high possibility. Moreover, antimicrobial studies of different bacterial and fungi indicated its promising antibacterial activity. cytotoxicity of the Tb complex and La complex was carried out in MCF-7 and A-549 cell lines, which revealed significantly good activity.Communicated by Ramaswamy H. Sarma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/07391102.2020.1792988DOI Listing
July 2020

Evaluation of parent and nano-encapsulated terbium(III) complex toward its photoluminescence properties, FS-DNA, BSA binding affinity, and biological applications.

J Trace Elem Med Biol 2020 May 21;61:126564. Epub 2020 May 21.

Department of Physical and Environmental Sciences, University of Toronto Scarborough 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada. Electronic address:

Background: There is a crucial need for finding and developing new compounds as the anticancer and antimicrobial agents with better activity, specific target, and less toxic side effects.

Objectives: Base on the potential anticancer properties of lanthanide complexes, in the paper, the biological applications of terbium (Tb) complex, containing 2,9-dimethyl- 1,10-phenanthroline (MePhen) such as anticancer, antimicrobial, DNA cleavage ability, the interaction with FS-DNA (Fish-Salmon DNA) and BSA (Bovine Serum Albumin) was examined.

Methods: The interaction of Tb-complex with BSA and DNA was studied by emission spectroscopy, absorption titration, viscosity measurement, CD spectroscopy, competitive experiments, and docking calculation. Also, the ability of this complex to cleave DNA was reported by gel electrophoresis. Tb-complex was concurrently screened for its antibacterial activities by different methods. Besides, the nanocarriers of Tb-complex (lipid nanoencapsulation (LNEP) and the starch nanoencapsulation (SNEP)), as active anticancer candidates, were prepared. MTT technique was applied to measure the antitumor properties of these compounds on human cancer cell lines.

Results: The experimental and docking results suggest significant binding between DNA as well as BSA with terbium-complex. Besides, groove binding plays the main role in the binding of this compound with DNA and BSA. The competitive experiment with hemin demonstrated that the terbium complex was bound at site III of BSA, which was confirmed by the docking study. Also, Tb-complex was concurrently screened for its DNA cleavage, antimicrobial, and anticancer activities. The anticancer properties of LNEP and SNEP are more than the terbium compound.

Conclusions: Tb-complex can bond to DNA/BSA with high binding affinity. Base on biological applications of Tb-complex, it can be concluded that this complex and its nanocarriers can suggest as novel anticancer, antimicrobial candidates.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jtemb.2020.126564DOI Listing
May 2020

Graphene Oxide Nanoribbons in Chitosan for Simultaneous Electrochemical Detection of Guanine, Adenine, Thymine and Cytosine.

Biosensors (Basel) 2020 Mar 27;10(4). Epub 2020 Mar 27.

Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada.

Herein, graphene oxide nanoribbons (GONRs) were obtained from the oxidative unzipping of multi-walled carbon nanotubes. Covalent coupling reaction of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxy succinimide (NHS) with amine functional groups (-NH) of the chitosan natural polymer (CH) was used for entrapping GONRs on the activated glassy carbon electrode (GCE/GONRs-CH). The nanocomposite was characterized by high-resolution transmission electron microscopy (HRTEM), and field-emission scanning electron microscopy (FESEM). In addition, the modification steps were monitored using FTIR. The nanocomposite-modified electrode was used for the simultaneous electrochemical determination of four DNA bases; guanine (G), adenine (A), thymine (T) and cytosine (C). The nanocomposite-modified GCE displayed a strong, stable and continuous four oxidation peaks during electrochemistry detection at potentials 0.63, 0.89, 1.13 and 1.27 V for G, A, T and C, respectively. The calibration curves were linear up to 256, 172, 855 and 342 μM with detection limits of 0.002, 0.023, 1.330 and 0.641 μM for G, A, T and C, respectively. The analytical performance of the GCE/GONRs-CH has been used for the determination of G, A, T and C in real samples and obtained a recovery percentage from 91.1%-104.7%. Our preliminary results demonstrated that GCE/GONRs-CH provided a promising platform to detect all four DNA bases for future studies on DNA damage and mutations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/bios10040030DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7236021PMC
March 2020

Thiol functionalized carbon ceramic electrode modified with multi-walled carbon nanotubes and gold nanoparticles for simultaneous determination of purine derivatives.

Mater Sci Eng C Mater Biol Appl 2020 May 19;110:110568. Epub 2019 Dec 19.

Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada. Electronic address:

In this proof-of-concept study, a thiol-functionalized sol-gel-based carbon ceramic electrode (CCE) was developed. This CCE was further modified by immobilizing gold nanoparticles (AuNP) in the thiol-functionalized ceramic matrix as well as incorporating multi-walled carbon nanotubes (MWCNT) within the pores of this ceramic sol-gel. The proposed electrode (MWCNT-AuNP-CCE) was used for the simultaneous determination of purine derivatives, uric acid (UA), xanthine (XA) and caffeine (CA). The simultaneous detection of these compounds is essential because these purine derivatives often coexist in real samples. Moreover, since these analytes have the capacity to interchange structures, developing a simultaneous detector is important. This electrode was successfully characterized using environmental scanning electron microscopy (ESEM) with secondary and back scattering electron detectors, energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM), and Fourier-transform infrared (FT-IR) spectroscopy. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) measurements were performed in phosphate buffer solution (0.1 M PBS, pH 6) at a potential window of 0.2 to 1.1 V (vs. Ag/AgCl). The proposed modified electrode (MWCNT-AuNP-CCE) displayed three well-defined, stable and continuous oxidation peaks at 0.3, 0.7 and 1.0 V for UA, XA, and CA, respectively. The resulting catalytic current at the surfaces showed a linear dependence to the concentrations of UA, XA and CA for up to 225, 225 and 1500 μM, respectively. The limit of detection was determined to be 50, 63 and 354 nM for UA, XA and CA, respectively. The analytical performance of MWCNT-AuNP-CCE was challenged with real samples such as human serum and urine with recoveries ranging between 98.1 and 102.6%. Moreover, the selectivity of sensor was further challenged with very similar purine molecules, theobromine and theophylline, which contain one less methyl group than CA. Overall, MWCNT-AuNP-CCE exhibited a promising platform for the future development of sensitive electrochemical sensors for the detection of purine derivatives in real samples.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.msec.2019.110568DOI Listing
May 2020

Simultaneous Determination of Four DNA bases at Graphene Oxide/Multi-Walled Carbon Nanotube Nanocomposite-Modified Electrode.

Micromachines (Basel) 2020 Mar 11;11(3). Epub 2020 Mar 11.

Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada.

In this study, we developed a modified glassy carbon electrode (GCE) with graphene oxide, multi-walled carbon nanotube hybrid nanocomposite in chitosan (GCE/GO-MWCNT-CHT) to achieve simultaneous detection of four nucleobases (i.e., guanine (G), adenine (A), thymine (T) and cytosine (C)) along with uric acid (UA) as an internal standard. The nanocomposite was characterized using TEM and FT-IR. The linearity ranges were up to 151.0, 78.0, 79.5, 227.5, and 162.5 µM with a detection limit of 0.15, 0.12, 0.44, 4.02, 4.0, and 3.30 µM for UA, G, A, T, and C, respectively. Compared to a bare GCE, the nanocomposite-modified GCE demonstrated a large enhancement (~36.6%) of the electrochemical active surface area. Through chronoamperometric studies, the diffusion coefficients (), standard catalytic rate constant (K), and heterogenous rate constant (K) were calculated for the analytes. Moreover, the nanocomposite-modified electrode was used for simultaneous detection in human serum, human saliva, and artificial saliva samples with recovery values ranging from 95% to 105%.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/mi11030294DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7143941PMC
March 2020

Prussian blue-doped nanosized polyaniline for electrochemical detection of benzenediol isomers.

Anal Bioanal Chem 2020 Mar 10;412(8):1769-1784. Epub 2020 Feb 10.

Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada.

Simultaneous speciation of benzenediol isomers (BDIs), 1,2-benzenediol (catechol, CC), 1,3-benzenediol (resorcinol, RS), and 1,4-benzenediol (hydroquinone, HQ), was investigated by differential pulse voltammetry (DPV) using a graphite paste electrode (GPE) modified with Prussian blue-polyaniline nanocomposite. The modified GPE showed good stability, sensitivity, and selectivity properties for all the three BDIs. Prussian blue-doped nanosized polyaniline (PBNS-PANI) was synthesized first by using mechanochemical reactions between aniline and ferric chloride hexahydrate as the oxidants and then followed by the addition of potassium hexacyanoferrate(II) in a solid-state and template-free technique. The material was characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The DPV measurements are performed in phosphate electrolyte solution with pH 4.0 at a potential range of - 0.1 to 1.0 V. The proposed modified electrode displayed a strong, stable, and continuous three well-separated oxidation peaks towards electrooxidation at potentials 0.20, 0.31, and 0.76 V for HQ, CC, and RS, respectively. The calibration curves were linear from 1 to 350.5 μM for both HQ and CC, while for RS, it was from 2 to 350.5 μM. The limit of detection was determined to be 0.18, 0.01, and 0.02 μM for HQ, CC, and RS, respectively. The analytical performance of the PBNS-PANI/GPE has been evaluated for simultaneous determination of HQ, CC, and RS in creek water, commercial hair dye, and skin whitening cream samples with satisfactory recoveries between 90 and 106%. Overall, we demonstrated that the presence of NS-PANI and PB resulted in a large redox-active surface area that enabled a promising analytical platform for simultaneous detection of BDIs. Graphical abstract.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00216-020-02400-6DOI Listing
March 2020

Experimental and theoretical investigations of Dy(III) complex with 2,2'-bipyridine ligand: DNA and BSA interactions and antimicrobial activity study.

J Biomol Struct Dyn 2020 Oct 14;38(16):4746-4763. Epub 2019 Nov 14.

Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada.

In this study, the interactions of a novel metal complex [Dy(bpy)Cl.OH] (bpy is 2,2'-bipyridine) with fish salmon DNA (FS-DNA) and bovine serum albumin (BSA) were investigated by experimental and theoretical methods. All results suggested significant binding between the Dy(III) complex with FS-DNA and BSA. The binding constants (), Stern-Volmer quenching constants () of Dy(III)-complex with FS-DNA and BSA at various temperatures as well as thermodynamic parameters using Van't Hoff equation were obtained. The experimental results from absorption, ionic strength, iodide ion quenching, ethidium bromide (EtBr) quenching studies and positive Δ˚ and Δ˚ suggested that hydrophobic groove-binding mode played a predominant role in the binding of Dy(III)-complex with FS-DNA. Indeed, the molecular docking results for DNA-binding were in agreement with experimental data. Besides, the results found from experimental and molecular modeling indicated that the Dy(III)complex bound to BSA Van der Waals interactions. Moreover, the results of competitive tests by phenylbutazone, ibuprofen, and hemin (as a site-I, site-II and site-III markers, respectively) considered that the site-III of BSA is the most possible binding site for Dy(III)-complex. In addition, Dy(III) complex was concurrently screened for its antimicrobial activities. The presented data provide a promising platform for the development of novel metal complexes that target nucleic acids and proteins with antimicrobial activity.Communicated by Ramaswamy H. Sarma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/07391102.2019.1689170DOI Listing
October 2020

Catalyst Behavior Analyzed via General Regression Model with the Parameters Depending on a Covariate.

ACS Omega 2018 Dec 6;3(12):16795-16804. Epub 2018 Dec 6.

Department of Statistics, Department of Chemistry, and Renewable Energies Research Institute, University of Sistan and Baluchestan, P.O. Box 98135-674, Zahedan, Iran.

In this work, the catalytic activity of modified glassy carbon electrodes with Pd-LaNiFeO-chitosan as an anodic catalyst for the polymeric fuel cell was investigated with cyclic voltammetry and controlled potential coulometry techniques; and are the mass loading of noble metal and mixed oxide, respectively. For the first time, the statistical regression mixed models were used to compare the electrocatalytic ability of nanocomposites in a fuel cell. The nonlinear regression model of = ( , ( )) + ε was considered and simulated, where is a random variable, is a covariate value, ε is a normal random error variable, and θ is a P-dimensional vector of parameters of the mentioned model. A strategy to make a mixed model was proposed by using the maximum likelihood or mean square error methods. Then, the appropriate linear and nonlinear models were applied to the electrochemical results. The equations of current density vs time were obtained via the fitting and simulation of experimental data at different potentials and mass loadings of components. The amounts of transferred charge during the methanol oxidation were calculated vs time through the integration of mentioned equations at different potentials and mass loadings of components.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsomega.8b01417DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6644165PMC
December 2018

An environmentally friendly one-pot synthesis method by the ultrasound assistance for the decoration of ultrasmall Pd-Ag NPs on graphene as high active anode catalyst towards ethanol oxidation.

Ultrason Sonochem 2019 Nov 30;58:104616. Epub 2019 May 30.

Department of Chemistry, University of Sistan and Baluchestan, P.O. Box 98135-674, Zahedan, Iran.

An environmentally friendly one-pot synthesis approach for the decoration of Pd-Ag nanoparticles with the ultrasmall size on graphene (Pd-Ag/G) by the assistance of ultrasound is proposed in this paper. This method offers exceptional advantages over other approaches such as environmentally friendly synthesis, being low temperature, reductant, surfactant free, simple, fast and one-pot synthesis. In this work, silver formate is added to the graphene suspension at 25 °C. Then, PdCl is added to the suspension under stirring to fabricate Pd-Ag/G. The uniform dispersity of nanoparticles with an average size of about 2-3 nm is well confirmed by transmission electron microscopy micrographs. The resultant catalyst is applied as anode electrocatalyst towards electrooxidation reaction of ethanol. The Pd-Ag/G catalyst displays exceptional catalytic activity and durability towards electro-oxidation of ethanol. According to the obtained results, it be concluded that the combination of Ag and Pd, ultrasmall and uniform distribution of Pd-Ag nanoparticles led to the improvement of electrocatalytic activity of the Pd-Ag/G catalyst.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ultsonch.2019.104616DOI Listing
November 2019

Evaluation of DNA, BSA binding, DNA cleavage and antimicrobial activity of ytterbium(III) complex containing 2,2'-bipyridine ligand.

J Biomol Struct Dyn 2020 Apr 27;38(6):1711-1725. Epub 2019 May 27.

Department of Chemistry, University of Sistan and Baluchestan, Zahedan, Iran.

In order to estimate the biological potential of a synthesized complex [Yb(bpy)Cl.OH] where bpy is 2,2'-bipyridine, its binding behavior with fish salmon-DNA (FS-DNA) and bovine serum albumin (BSA) were studied by different kinds of spectroscopy and molecular modeling methods. This complex was selected for its antibacterial and antifungal activities as well as the DNA cleavage activities were examined by agarose gel electrophoresis. The analyses of fluorescence data at four temperatures were done in order to evaluate the binding and thermodynamic parameters of the interaction of Yb(III) complex with DNA and BSA. The experimental results indicated that the major binding modes were based on groove binding with DNA and BSA. In addition, iodide quenching studies, ethidium bromide (EtBr) exclusion assay, ionic strength effect, circular dichroism, and viscosity studies reflected the binding of Yb(III) complex explicitly with the FS-DNA mainly in a groove binding mode. Moreover, molecular docking studies indicated that this complex was bound to the minor groove of DNA and to polar and apolar residues located in the subdomain IB of BSA (site 3). Also, the results of competitive experiments assessed site 3 of BSA as the most probable binding site for this complex. The molecular docking results were in good agreement with our experimental results. From both experimental and docking results, the binding constant values displayed the remarkably high affinity of Yb(III) complex to DNA as well as BSA.Communicated by Ramaswamy H. Sarma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/07391102.2019.1617788DOI Listing
April 2020

Nanoraspberry-like copper/ reduced graphene oxide as new modifier for simultaneous determination of benzenediols isomers and nitrite.

Anal Chim Acta 2019 May 26;1056:16-25. Epub 2018 Dec 26.

Analytical Research Laboratory, Department of Chemistry, University of Sistan and Baluchestan, Zahedan, P.O. Box 98135-674, Iran. Electronic address:

In this study, immobilized nanoraspberry-like copper on the reduced graphene oxide (NRCu-rGO) was synthesized and used for modification of glassy carbon electrode (GCE) for selective and sensitive simultaneous determination of benzenediols isomers; hydroquinone (HQ), catechol (CC), resorcinol (RS) as well as nitrite (NO). A detailed investigation such as field emission scanning electron microscopy, energy dispersive X-ray analysis, and X-ray diffraction as well as electrochemistry methods such as cyclic voltammetry, electrochemical impedance spectroscopy, differential pulse voltammetry (DPVs) and chronoamperometry are performed in order to elucidate the preparation process and properties of the NRCu-rGO/GCE. DPVs peak currents increased linearly with the analytes concentrations within the ranges of 0.13-131.5 μM for HQ, CC, RS and 0.3-131.5 μM for NO with a detection limits 49, 52, 60 and 100 nM for HQ, CC, RS and NO, respectively. The proposed modified electrode was successfully used for simultaneous determination of HQ, CC, RS and NO in real samples.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.aca.2018.12.036DOI Listing
May 2019

2D-Single-crystal hexagonal gold nanosheets for ultra-trace voltammetric determination of captopril.

Mikrochim Acta 2019 02 19;186(3):195. Epub 2019 Feb 19.

Analytical Research Laboratory, Department of Chemistry, University of Sistan and Baluchestan, P.O. Box 98135-674, Zahedan, 98167-45845, Iran.

Two dimensional single-crystal hexagonal gold nanosheets (SCHGNSs) were prepared by microwave heating of a solution of HAuCl in an ionic liquid. The SCHGNSs were characterized by field emission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, atomic force microscopy and electrochemical impedance spectroscopy. The SCHGNSs were then used to modify a graphite paste electrode for voltammetric determination of the hypertension drug captopril (CAP). The modified electrode showed a well-defined oxidation peak (at 0.41 V vs. Ag/AgCl) at pH 7.0 using differential pulse voltammetry. Under the optimum conditions, the response is linear in the 2-400 nM and 4.0-50 μM CAP concentration range, and the detection limit (at S/N = 3) is 0.3 nM. The sensor was successfully applied to the determination of CAP in pharmaceutical tablets and in spiked urine. Graphical abstract Schematic presentation of the preparation of single crystal hexagonal gold nanosheets and their use to modify a carbon paste electrode for ultra-trace voltammetric determination of the drug captopril.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00604-019-3260-9DOI Listing
February 2019

Complex formation between the Escherichia coli [NiFe]-hydrogenase nickel maturation factors.

Biometals 2019 06 13;32(3):521-532. Epub 2019 Feb 13.

Department of Chemistry, University of Toronto, Toronto, ON, M5S 3H6, Canada.

The biosynthesis of the dinuclear metal cluster at the active sites of the [NiFe]-hydrogenase enzymes is a multi-step process executed by a suite of accessory proteins. Nickel insertion during maturation of Escherichia coli [NiFe]-hydrogenase 3 is achieved by the metallochaperones HypA, SlyD and the GTPase HypB, but how these proteins cooperate to ensure nickel delivery is not known. In this study, the complexes formed between the individual purified proteins were examined by using several methods. Size exclusion chromatography (SEC) indicated that SlyD and HypB interact primarily in a 1:1 complex. The affinity of HypB-SlyD was measured by using surface plasmon resonance, which revealed a K of 24 ± 10 nM in the absence of nucleotide and an interaction several fold tighter in the presence of GDP. A ternary complex between all three proteins was not detected, and instead SlyD blocked the interaction of HypA with HypB in competitive binding experiments. Furthermore, cross-linking experiments suggest a weak interaction between HypA and SlyD, which is not detectable by SEC. Electrochemical analysis confirmed each of the pairwise interactions and that the relative affinities of these complexes are on the order of HypB-SlyD > HypB-HypA > HypA-SlyD. These results indicate a hierarchy of interactions, as opposed to a single multiprotein complex, and provide insight into the nickel delivery process during hydrogenase enzyme maturation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10534-019-00173-9DOI Listing
June 2019

cytotoxicity studies of parent and nanoencapsulated Holmium-2,9-dimethyl-1,10-phenanthroline complex toward fish-salmon DNA-binding properties and antibacterial activity.

J Biomol Struct Dyn 2019 10 16;37(17):4437-4449. Epub 2019 Jan 16.

Department of Biotechnology, Institute of Science, High Technology & Environmental Science, Graduate University of Advance Technology , Kerman , Iran.

In this study, the interaction of Holmium (Ho) complex including 2, 9-dimethyl-1,10-phenanthroline, also called Neocuproine (Neo), [Ho(Neo)Cl.HO], as fluorescence probe with fish-salmon DNA (FS-DNA) is studied during experimental investigations. Multi-spectroscopic methods are utilized to determine the affinity binding constants () of complex-FS-DNA. It is found that fluorescence of Ho complex is strongly quenched by the FS-DNA through a static quenching procedure. Under optimal conditions in Tris(trishydroxymethyl-aminomethane)-HCl buffer at 25 °C with pH ≈ 7.2, intrinsic binding constant of Ho complex is 6.12 ± 0.04 × 10 M. Also, the binding site number and Stern-Volmer quenching constant are calculated. There are different approaches, including iodide quenching assay, salt effect and thermodynamical assessment to determine the features of the binding mode between Ho complex and FS-DNA. Also, the parent and starch and lipid nanoencapsulated Ho complex, as potent antitumor candidates, were synthesized. The main structure of Ho complex is maintained after encapsulation using starch and lipid nanoparticles. 3-[4,5-Dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) method was used to assess the anticancer properties of Ho complex and its encapsulated forms on human cancer cell lines of human lung carcinoma cell line and breast cancer cell line. In conclusion, these compounds could be considered as new antitumor candidates. Communicated by Ramaswamy H. Sarma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/07391102.2018.1557077DOI Listing
October 2019

Sonochemical synthesis of high-performance [email protected]/MWCNTs-CH electrocatalyst by galvanic replacement toward ethanol oxidation in alkaline media.

Ultrason Sonochem 2019 Mar 15;51:478-486. Epub 2018 Jun 15.

Department of Applied Chemistry, University of Sistan and Baluchestan, P.O. Box 98135-674, Zahedan, Iran.

In this paper, a fast and effective method for the palladium (Pd) wire nanostructures synthesis with the great surface area through galvanic replacement reaction utilizing copper nanowires (CuNWS) as a template by the assistance of ultrasound under room temperature condition is proposed. A multifunctional catalyst with the mentioned nanostructure, [email protected], and multi walled carbon nanotubes (MWCNTs) and chitosan (CH) as a binder was fabricated. To investigate the morphology and bulk composition of the prepared catalyst, Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray Spectroscopy (EDS), X-ray Powder Diffraction (XRD), and Inductively Coupled Plasma atomic Emission Spectroscopy (ICP-AES) were utilized. Various electrochemical techniques including chronoamperometry and cyclic voltammetry were employed for the electrocatalytic activity of ethanol electrooxidation and durability in basic solution. Electrochemical catalytic activity and durability evaluation results proved that the as-synthesized [email protected]/MWCNTs-CH has a super electrocatalytic activity compared to Pd/MWCNTs and Pd/C electrocatalysts for ethanol electrooxidation. [email protected]/MWCNTs-CH catalyst demonstrated substantially enhanced performance and long-term stability for ethanol electrooxidation in the basic solution in comparison to Pd/MWCNTs and commercial Pd/C demonstrated the potential in utilizing [email protected]/MWCNTs-CH as an efficient catalyst for ethanol oxidation. Additionally, thermodynamic and kinetic evaluations revealed that the [email protected]/MWCNTs-CH catalyst has lower activation energy compared to Pd/MWCNTs and Pd/C which leads to a lower energy barrier and an excellent charge transfer rate towards ethanol oxidation. Noticeably, the [email protected]/MWCNTs-CH presented excellent catalytic activities with high peak current density which was 9.5 times more than Pd/C, and more negative onset potential in comparison to Pd/C is acquired for ethanol electrooxidation denoting synergistic effect between CuNWs/MWCNs-CH and Pd. The [email protected]/MWCNTs-CH can be considered as a valid candidate among available electrocatalysts in direct ethanol fuel cells (DEFCs).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ultsonch.2018.06.011DOI Listing
March 2019

Investigation on the electrocatalytic activity and stability of three-dimensional and two-dimensional palladium nanostructures for ethanol and formic acid oxidation.

J Colloid Interface Sci 2018 Dec 4;532:485-490. Epub 2018 Aug 4.

Department of Chemistry, Faculty of Science, University of Sistan and Baluchestan, P.O. Box 98135-674, Zahedan, Iran.

Three dimensional (3-D) self-supported noble metal nanostructures are attractive for their unique properties of high porosity, low density, excellent charge, and mass transfer which increases catalytic activity. Herein, a facile route of preparing two-dimensional (2-D) palladium nanosheets and three-dimensional palladium nanostructure is introduced. By raising the temperature of the reaction mixture, it is possible for Pd nanosheets to change from 2-D into the 3-D structure. Morphology and chemical composition of the nanostructures are characterized by Transition Electron microscopy (TEM), Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDX). We reveal that the as-prepared 3-D Pd nanostructure shows a higher electrocatalytic activity and stability towards ethanol oxidation reaction (EOR) than 2-D Pd nanosheets, due to its porous nanostructures that renders a high surface area.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcis.2018.08.003DOI Listing
December 2018

Electronic and fluorescent studies on the interaction of DNA and BSA with a new ternary praseodymium complex containing 2,9-dimethyl 1,10-phenanthroline and antibacterial activities testing.

J Biomol Struct Dyn 2019 Jun 1;37(9):2283-2295. Epub 2018 Nov 1.

a Department of Chemistry , University of Sistan and Baluchestan , Zahedan , Iran.

In this study, fluorescence emission spectra, UV-vis absorption spectra, ethidium bromide (EB)-competition experiment, and iodide quenching experiment were used for the interaction study of the Fish salmon DNA (FS-DNA) with [Pr(dmp)2Cl3(OH2)] where dmp is 2,9-dimethyl 1,10-phenanthroline. The binding constant and the number of binding sites of the complex with FS-DNA were 6.09 ± 0.04 M and 1.18, respectively. The free energy, enthalpy, and entropy changes (ΔG°, ΔH°, and ΔS°) in the binding process of the Pr(III) complex with FS-DNA were -8.02 kcal mol, +39.44 kcal mol1, and +159.56 cal mol K, respectively. Based on these results, the interaction process between FS-DNA with [Pr(dmp)2Cl3(OH2)] was spontaneous and the main binding interaction force was groove binding mode. Also, Fluorescence and electronic absorption spectroscopy were used in order to evaluate the binding characteristics, stoichiometry, and interaction mode of praseodymium(III) (Pr(III)) complex with bovine serum albumin (BSA). Title complex showed good binding propensity to BSA presenting moderately high Kb values. The fluorescence quenching of BSA by Pr(III) complex has been observed to be the static process. The positive ΔH° and ΔS° values showed that the hydrophobic interaction is the main force in the binding of Pr(III) complex and BSA. Eventually, the average aggregation number, , of BSA potentially induced by title complex confirmed the 1:1 stoichiometry for title complex-BSA adducts. In vitro, antimicrobial activity of title complex was indicated that the complex is more active against both Escherichia coli and Enterococcus faecalis bacterial strains than Staphylococcus aureus, and Pseudomonas aeruginosa. Communicated by Ramaswamy H. Sarma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/07391102.2018.1479657DOI Listing
June 2019

Synthesis, characterization, and binding assessment with human serum albumin of three bipyridine lanthanide(III) complexes.

J Biomol Struct Dyn 2019 Apr 18;37(6):1438-1450. Epub 2018 May 18.

b Department of Chemistry , University of Sistan & Baluchestan , Zahedan 98155-147 , Iran.

In this work, the terbium(III), dysprosium(III), and ytterbium(III) complexes containing 2, 2'-bipyridine (bpy) ligand have been synthesized and characterized using CHN elemental analysis, FT-IR, UV-Vis and H-NMR techniques and their binding behavior with human serum albumin (HSA) was studied by UV-Vis, fluorescence and molecular docking examinations. The experimental data indicated that all three lanthanide complexes have high binding affinity to HSA with effective quenching of HSA fluorescence via static mechanism. The binding parameters, the type of interaction, the value of resonance energy transfer, and the binding distance between complexes and HSA were estimated from the analysis of fluorescence measurements and Förster theory. The thermodynamic parameters suggested that van der Waals interactions and hydrogen bonds play an important role in the binding mechanism. While, the energy transfer from HSA molecules to all these complexes occurs with high probability, the order of binding constants (BpyTb > BpyDy > BpyYb) represents the importance of radius of Ln ion in the complex-HSA interaction. The results of molecular docking calculation and competitive experiments assessed site 3 of HSA, located in subdomain IB, as the most probable binding site for these ligands and also indicated the microenvironment residues around the bound mentioned complexes. The computational results kept in good agreement with experimental data.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/07391102.2018.1464959DOI Listing
April 2019

Synthesis and Application of Phosphorus/CoO-CuO Hybrid as High-Performance Anode Materials for Lithium-Ion Batteries.

ACS Omega 2018 Apr 26;3(4):4620-4630. Epub 2018 Apr 26.

Department of Chemistry, University of Sistan and Baluchestan, Zahedan 9816745785, Iran.

The present study reports a novel red phosphorus (RP)/CoO-CuO hybrid as a high-performance anode material for lithium ion battery that was successfully synthesized by simple sol gel method and followed by facile ball milling of red phosphorus. Herein, we outstandingly improved practical application of RP anode (with its natural insulation property and rapid capacity decay in during the lithiation process) in lithium-ion batteries (LIBs) by confining nanosized amorphous RP into the CoO-CuO nanoparticle while RP can improve the electrochemical capacity returning and increased capacity of composite in high current density. This bonding can help maintain electrical contact, prevent to escape RP from the electrode and confirm the solid electrolyte interphase upon the large volume change of RP during cycling. As a result, by judicious usage of components in the RP/CoO-CuO hybrid nanostructured anode was achieved an initial Coulombic efficiency of 99.8% at a current density of 50 mA g and an enhanced cycling stability (683.63 and 470.11 mAh g after 60 cycles at a density of 0.1 and 1 A g) with interesting cycling capacity at high current density of 3 Ag (333.81 mAh g). Moreover, the composite electrode can still deliver a specific capacity of about 97.4% of initial capacity after cycling at high rates and returning to the initial current density of 0.1 A g.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsomega.7b01153DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6641369PMC
April 2018

Epigallocatechin Gallate-Modified Graphite Paste Electrode for Simultaneous Detection of Redox-Active Biomolecules.

Sensors (Basel) 2017 Dec 22;18(1). Epub 2017 Dec 22.

Department of Physical and Environmental Sciences, University of Toronto, Scarborough 1265 Military Trail, Toronto, ON M1C 1A4, Canada.

In this study, simultaneous electrochemical detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA) was performed using a modified graphite paste electrode (MGPE) with epigallocatechin gallate (EGCG) and green tea (GT) powder. It was shown that the anodic peak current increased in comparison with that of the graphite paste electrode (GPE) in the cyclic voltammograms. The optimal pH for simultaneous determination of a quaternary mixture of AA-DA-UA was determined to be pH 2. The anodic peak potentials for a mixture containing AA-DA-UA were well separated from each other. The catalytic peak currents obtained at the surface of the MGPE/EGCG were linearly dependent on the AA, DA, and UA concentrations up to 23, 14, and 14 µM, respectively. The detection limits for AA, DA, and UA were 190, 90, and 70 nM, respectively. The analytical performance of this sensor has been evaluated for simultaneous detection of AA, DA, and UA in real samples. Finally, a modified electrode was prepared using GT and used for simultaneous determination of AA, DA, and UA. Based on the results, MPGE/GT showed two oxidation peaks at 0.43 and 0.6 V for DA and UA, respectively, without any oxidation peak for AA. The calibration curves at the surface of MGPE/GT were linear up to 14 µM with a detection limit of 0.18 and 0.33 µM for DA and UA, respectively. MGPEs provide a promising platform for the future development of sensors for multiplexed electrochemical detection of clinically important analytes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/s18010023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5795891PMC
December 2017

Removing 2,4-dichlorophenol from aqueous environments by heterogeneous catalytic ozonation using synthesized MgO nanoparticles.

Water Sci Technol 2017 Dec;76(11-12):3054-3068

Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran E-mail:

2,4-Dichlorophenol (2,4-DCP) is one of the seriously toxic chlorophenol compounds found in agricultural environments, in water disinfected by chlorine, and in outgoing effluents from the pulp and paper industries and paper manufacturing factories. This research studied the feasibility of using MgO nanoparticles (MgO-NPs) as a catalyst in the ozonation process for removing 2,4-DCP from aqueous environments under laboratory conditions. This study was conducted using a laboratory-scale semi-continuous reactor. It studied the effects of critical variables such as solution pH, ozonation time, dose of MgO-NPs and initial 2,4-DCP concentration. A statistical model of response surface model (RSM) was designed and utilized to obtain the optimum experimental conditions. Analysis of the data showed that initial concentration of 2,4-DCP and dose of MgO-NPs had the maximum effect on the response variable (percentage degradation of 2,4-DCP). Moreover, based on analysis of variance on the model, the optimum removal conditions were reaction time of 50 min, pH > 7, initial 2,4-DCP concentration of less than 50 mg/L, and an MgO-NPs dose of 0.3 mg/L. Under these optimum conditions, a removal efficiency of 99.99% was achieved. In addition, results indicated that catalytic ozonation in the presence of MgO-NPs was very efficient at removing 2,4-DCP from aqueous environments.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2166/wst.2017.479DOI Listing
December 2017

Flow injection analysis-flame atomic absorption spectrometry system for indirect determination of sulfite after on-line reduction of solid-phase manganese (IV) dioxide reactor.

Talanta 2018 Feb 10;178:722-727. Epub 2017 Oct 10.

Department of Chemistry, University of Sistan and Baluchestan, Zahedan P.O. Box 98155-147, Iran.

A new and simple flow injection method followed by atomic absorption spectrometry was developed for indirect determination of sulfite. The proposed method is based on the oxidation of sulfite to sulphate ion using solid-phase manganese dioxide (30% W/W suspended on silica gel beads) reactor. MnO will be reduced to Mn(II) by sample injection in to the column under acidic carrier stream of HNO (pH 2) with flow rate of 3.5mLmin at room temperature. Absorption measurement of Mn(II) which is proportional to the concentration of sulfite in the sample was carried out by atomic absorption spectrometry. The calibration curve was linear up to 25mgL with a detection limit (DL) of 0.08mgL for 400µL injection sample volume. The presented method is efficient toward sulfite determination in sugar and water samples with a relative standard deviation (RSD) less than 1.2% and a sampling rate of about 60h.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.talanta.2017.10.012DOI Listing
February 2018

New synthesis of poly ortho-methoxyaniline nanostructures and its application to construct modified multi-wall carbon nanotube/graphite paste electrode for simultaneous determination of uric acid and folic acid.

Mater Sci Eng C Mater Biol Appl 2017 Jun 27;75:791-797. Epub 2017 Feb 27.

Analytical Research Laboratory, Department of Chemistry, University of Sistan and Baluchestan, Zahedan, P.O. Box 98155-674, Iran.

Uric acid (UA) and folic acid (FA) are compounds of biomedical interest. In humans, about 70% of daily uric acid disposal occurs via the kidneys, and in 5-25% of humans, impaired renal (kidney) excretion leads to hyperuricemia. Folate is another form folic acid of which is known as, is one of the B vitamins. It is used as a supplement by women to prevent neural tube defects developing during pregnancy. Polyortho-methoxyaniline nanostructures (POMANS) was synthesized with a new two phase (organic-water) synthesis method. The POMANS was characterized using transmission electron microscopy (TEM) and Fourier transform IR (FTIR). This polymer was used to construct a modified multi-wall carbon nanotube, graphite paste electrode (POMANS-MWCNT/GPE). Linear sweep voltammograms (LSV), cyclic voltammetry (CV) and chronoamperometry were used to investigate the suitability of polyortho-methoxyaniline with multi-wall carbon nanotubes paste electrode as a modifier for the electrocatalytic oxidation of UA and FA in aqueous solutions with various pHs. The results showed that POMANS-MWCNT/GPE had high anodic peak currents for the electrooxidation of UA and FA in pH6.0.Under the optimized conditions, The catalytic peak currents obtained, was linearly dependent on the UA and FA concentrations in the range of 0.6-52 and 0.5-68μM with two segments and the detection limits 0.157 and 0.113μM for UA and FA were, respectively. Finally, the proposed method was also examined as a sensitive, simple and inexpensive electrochemical sensor for the simultaneous determination of UA and FA in real samples such as urine and serum.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.msec.2017.02.133DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5402925PMC
June 2017

Evaluation of DNA, BSA binding, and antimicrobial activity of new synthesized neodymium complex containing 29-dimethyl 110-phenanthroline.

J Biomol Struct Dyn 2018 02 21;36(3):779-794. Epub 2017 Feb 21.

a Department of Chemistry , University of Sistan and Baluchestan , Zahedan , P.O. Box 98155-147 , Iran.

In order to evaluate biological potential of a novel synthesized complex [Nd(dmp)Cl.OH] where dmp is 29-dimethyl 110-phenanthroline, the DNA-binding, cleavage, BSA binding, and antimicrobial activity properties of the complex are investigated by multispectroscopic techniques study in physiological buffer (pH 7.2).The intrinsic binding constant (K) for interaction of Nd(III) complex and FS-DNA is calculated by UV-Vis (K = 2.7 ± 0.07 × 10) and fluorescence spectroscopy (K = 1.13 ± 0.03 × 10). The Stern-Volmer constant (K), thermodynamic parameters including free energy change (ΔG°), enthalpy change (∆H°), and entropy change (∆S°), are calculated by fluorescent data and Vant' Hoff equation. The experimental results show that the complex can bind to FS-DNA and the major binding mode is groove binding. Meanwhile, the interaction of Nd(III) complex with protein, bovine serum albumin (BSA), has also been studied by using absorption and emission spectroscopic tools. The experimental results show that the complex exhibits good binding propensity to BSA. The positive ΔH° and ∆S° values indicate that the hydrophobic interaction is main force in the binding of the Nd(III) complex to BSA, and the complex can quench the intrinsic fluorescence of BSA remarkably through a static quenching process. Also, DNA cleavage was investigated by agarose gel electrophoresis that according to the results cleavage of DNA increased with increasing of concentration of the complex. Antimicrobial screening test gives good results in the presence of Nd(III) complex system.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/07391102.2017.1288170DOI Listing
February 2018

Evaluation DNA-/BSA-binding properties of a new europium complex containing 2,9-dimethyl-1,10-phenanthroline.

J Biomol Struct Dyn 2017 05 11;35(7):1518-1528. Epub 2016 Aug 11.

a Department of Chemistry , University of Sistan and Baluchestan , Zahedan , Iran.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/07391102.2016.1188419DOI Listing
May 2017

Synthesis and biological evaluation of a new dysprosium(III) complex containing 2,9-dimethyl 1,10-phenanthroline.

J Biomol Struct Dyn 2017 Feb 14;35(2):300-311. Epub 2016 Apr 14.

a Department of Chemistry , University of Sistan and Baluchestan , P.O. Box 98155-147, Zahedan , Iran.

The binding of [Dy(dmp)Cl(OH)], where dmp is 2,9-dimethyl 1,10-phenanthroline, with Fish salmon DNA (FS-DNA) is investigated by absorption and emission spectroscopy, quenching studies, salt dependent, and gel electrophoresis. The binding constant (K) of the interaction is calculated as (1.27 ± .05) × 10 M from absorption spectral titration data. The Stern-Volmer constant (K), thermodynamic parameters involves ΔG°, ∆H°, and ∆S° are calculated by fluorescent data and Van't Hoff equation. The thermodynamic studies show that the reaction for the binding of the complex with FS-DNA is endothermic and entropically driven (ΔS° > 0, ΔH° > 0). The effect of the complex concentration on FS-DNA cleavage reactions is also investigated by gel electrophoresis. Furthermore, the Dy(III) complex has been screened for its antibacterial activity. The experimental results suggest that the Dy(III) complex binds significantly to FS-DNA by hydrophobic groove binding mode and the complex has more efficient antibacterial activity compared to its metal salt.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/07391102.2015.1137491DOI Listing
February 2017

DNA interaction of europium(III) complex containing 2,2'-bipyridine and its antimicrobial activity.

J Biomol Struct Dyn 2016 8;34(3):612-24. Epub 2015 Jun 8.

a Department of Chemistry , University of Sistan and Baluchestan , Zahedan , P.O. Box 98155-147, Iran.

The interaction of native fish salmon DNA (FS-DNA) with [Eu(bpy)3Cl2(H2O)]Cl, where bpy is 2,2'-bipyridine, is studied at physiological pH in Tris-HCl buffer by spectroscopic methods, viscometric techniques as well as circular dichroism (CD). These experiments reveal that Eu(III) complex has interaction with FS-DNA. Moreover, binding constant and binding site size have been determined. The value of Kb has been defined 2.46 ± .02 × 10(5) M(-1). The thermodynamic parameters are calculated by Van't Hoff equation, the results show that the interaction of the complex with FS-DNA is an entropically driven phenomenon. CD spectroscopy followed by viscosity as well as fluorescence and UV--Vis measurements indicate that the complex interacts with FS-DNA via groove binding mode. Also, the synthesized Eu(III) complex has been screened for antimicrobial activities.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/07391102.2015.1048481DOI Listing
December 2016

Multispectroscopic DNA-binding studies of a terbium(III) complex containing 2,2'-bipyridine ligand.

J Biomol Struct Dyn 2016 23;34(2):414-26. Epub 2015 Jun 23.

a Department of Chemistry , University of Sistan and Baluchestan , P.O. Box 98155-147, Zahedan , Iran.

Agarose gel electrophoresis, absorption, fluorescence, viscosity, and circular dichroism (CD) have been used in exploring the interaction of terbium(III) complex, [Tb(bpy)2Cl3(OH2)] where bipy is 2,2'-bipyridine, with Fish salmon DNA. Agarose gel electrophoresis assay, along with absorption and fluorescence studies, reveal interaction between the corresponding complex and FS-DNA. Also, the binding constants (Kb) and the Stern-Volmer quenching constants (Ksv) of Tb(III) complex with FS-DNA were determined. The calculated thermodynamic parameters suggested that the binding of mentioned complex to FS-DNA was driven mainly by hydrophobic interactions. A comparative study of this complex with respect to the effect of iodide-induced quenching, ionic strength effect, and ethidium bromide exclusion assay reflects binding of explicit to the FS-DNA primarily in a groove fashion. CD and viscosity data also support the groove binding mode. Furthermore, Tb(III) complex have been simultaneously screened for their antibacterial and antifungal activities.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/07391102.2015.1038585DOI Listing
October 2016

Development of glassy carbon electrode modified with ruthenium red-multiwalled carbon nanotubes for simultaneous determination of epinephrine and acetaminophen.

Anal Sci 2014 ;30(9):911-8

Department of Chemistry, University of Sistan and Baluchestan.

A glassy carbon electrode modified with ruthenium red and functionalized multi-walled carbon nanotube has been developed. The electrochemical response characteristics of the modified electrode toward epinephrine (EP) and acetaminophen (AC) was investigated by differential pulse voltammetry (DPV). Linear calibration plots were obtained over the range of 0.3 - 333.3 μM for both EP and AC with sensitivities of 0.221 and 0.174 μA μM(-1) for EP and AC, respectively. The detection limits for EP and AC were 0.04 and 0.06 μM, respectively. The diffusion coefficients for the oxidation of EP and AC at the modified electrode were calculated as 2.74 ± 0.05 × 10(-5) and 1.75 ± 0.07 × 10(-5) cm(2) s(-1), respectively. The practical analytical utilities of the modified electrode were demonstrated by the determination of EP and AC in human urine and serum as well as AC tablet samples.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2116/analsci.30.911DOI Listing
May 2015

Fluorescence studies, DNA binding properties and antimicrobial activity of a dysprosium(III) complex containing 1,10-phenanthroline.

J Photochem Photobiol B 2013 Oct 29;127:192-201. Epub 2013 Aug 29.

Department of Chemistry, University of Sistan & Baluchestan, P.O. Box 98155-147, Zahedan, Iran. Electronic address:

Luminescence and binding properties of dysprosium(III) complex containing 1,10-phenanthroline (phen), [Dy(phen)2(OH2)3Cl]Cl2⋅H2O with DNA has been studied by electronic absorption, emission spectroscopy and viscosity measurement. The thermodynamic studies suggest that the interaction process to be endothermic and entropically driven, which indicates that the dysprosium(III) complex might interact with DNA by a non intercalation binding mode. Additionally, the competitive fluorescence study with ethidium bromide and also the effect of iodide ion and salt concentration on fluorescence of the complex-DNA system is investigated. Experimental results indicate that the Dy(III) complex strongly binds to DNA, presumably via groove binding mode. Furthermore, the complex shows a potent antibacterial activity and DNA cleavage ability.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jphotobiol.2013.08.009DOI Listing
October 2013