Publications by authors named "Mahroo Baharfar"

12 Publications

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Microfluidic-enabled versatile hyphenation of electromembrane extraction and thin film solid phase microextraction.

Talanta 2021 Mar 5;224:121864. Epub 2020 Nov 5.

Department of Analytical Chemistry, Faculty of Chemistry, K. N. Toosi University of Technology, Tehran, Iran.

In the present study, a versatile combination of electromembrane extraction (EME) with thin film solid phase microextraction (TF-SPME) was introduced using a microfluidic chip device. The device consisted of two single channels on two separate layers. The upper channel was dedicated to donor phase flow pass, while the beneath channel was used as a reservoir for stagnant acceptor solution. A slide of fluorine doped tin oxide (FTO) was accommodated in the bottom of the acceptor phase channel. A thin layer of polyaniline was electrodeposited on the FTO surface to achieve the required thin film for TF-SPME. A stainless-steel wire was embedded in the donor phase channel and another wire was also attached to the FTO surface. The channels were separated by a piece of polypropylene membrane impregnated with 1-octanol and the whole chip was fixed with bolts and nuts. The driving force for the extraction was an 8 V direct current (DC) voltage applied across the supported liquid membrane (SLM). Under the influence of the electrical field, analytes immigrated from sample towards the acceptor phase and then adsorbed on the thin film of the solid phase. Finally, the analytes were desorbed by successive movement of a desorption solvent in the acceptor phase channel followed by injection of the desorption solution to HPLC-UV. The applicability of the proposed device was demonstrated by the determination of four synthetic food dyes: Amaranth, Ponceau 4R, Allura Red, and Carmoisine, as the model analytes. The effective parameters on the efficiency of the both EME and TF-SPME were investigated. Under the optimized conditions, the microchip provided low LODs (1-10 μg L), and a wide linear dynamic range of 10-1000 μg L for all analytes. The system also offered RSD values lower than 5.5% and acceptable reusability of the thin film for multiple extractions.
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http://dx.doi.org/10.1016/j.talanta.2020.121864DOI Listing
March 2021

Current methods for diagnosis of human coronaviruses: pros and cons.

Anal Bioanal Chem 2021 Apr 20;413(9):2311-2330. Epub 2020 Nov 20.

Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, 2052, Australia.

The current global fight against coronavirus disease (COVID-19) to flatten the transmission curve is put forth by the World Health Organization (WHO) as there is no immediate diagnosis or cure for COVID-19 so far. In order to stop the spread, researchers worldwide are working around the clock aiming to develop reliable tools for early diagnosis of severe acute respiratory syndrome (SARS-CoV-2) understanding the infection path and mechanisms. Currently, nucleic acid-based molecular diagnosis (real-time reverse transcription polymerase chain reaction (RT-PCR) test) is considered the gold standard for early diagnosis of SARS-CoV-2. Antibody-based serology detection is ineffective for the purpose of early diagnosis, but a potential tool for serosurveys, providing people with immune certificates for clearance from COVID-19 infection. Meanwhile, there are various blooming methods developed these days. In this review, we summarise different types of coronavirus discovered which can be transmitted between human beings. Methods used for diagnosis of the discovered human coronavirus (SARS, MERS, COVID-19) including nucleic acid detection, gene sequencing, antibody detection, antigen detection, and clinical diagnosis are presented. Their merits, demerits and prospects are discussed which can help the researchers to develop new generation of advanced diagnostic tools for accurate and effective control of human coronavirus transmission in the communities and hospitals.
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http://dx.doi.org/10.1007/s00216-020-03046-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7679240PMC
April 2021

Microextraction on a screw for determination of trace amounts of hexanal and heptanal as lung cancer biomarkers.

J Pharm Biomed Anal 2020 Nov 22;191:113528. Epub 2020 Aug 22.

Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran.

Solid phase microextraction on a screw was utilized for the extraction of hexanal and heptanal as lung cancer biomarkers from urine samples. Reduced graphene oxide (rGO) was coated on the surface of a stainless-steel set screw by electrophoretic deposition method. The screw was located inside a glass cover, and the created channel acted as the sample solution flow pass. A 5 mL glass syringe was connected to a syringe pump to direct the sample and the eluent through the channel. The extraction procedure was followed by gas chromatography/mass spectrometry (GC/MS) for separation and determination of the extracted aldehydes. The effective parameters on the extraction efficiencies of the analytes were identified and optimized. Under the optimal extraction conditions, the extraction time was as short as 10 min. The calibration curves indicated good linearity (R > 0.97) within the concentration range of 1.0-50 μg L. The obtained limits of detection (LODs) for hexanal and heptanal were down to 0.4 and 0.3 μg L, respectively. Considering the repeatability, simplicity, and eco-friendliness of this simple extraction method, it can be efficiently used for preconcentration of aldehydes in different samples.
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http://dx.doi.org/10.1016/j.jpba.2020.113528DOI Listing
November 2020

Engineering strategies for enhancing the performance of electrochemical paper-based analytical devices.

Biosens Bioelectron 2020 Nov 8;167:112506. Epub 2020 Aug 8.

Graduate School of Biomedical Engineering, The University of New South Wales, Sydney NSW, 2052, Australia. Electronic address:

Applications of electrochemical detection methods in microfluidic paper-based analytical devices (μPADs) has revolutionized the area of point-of-care (POC) testing towards highly sensitive and selective quantification of various (bio)chemical analytes in a miniaturized, low-coat, rapid, and user-friendly manner. Shortly after the initiation, these relatively new modulations of μPADs, named as electrochemical paper-based analytical devices (ePADs), gained widespread popularity within the POC research community thanks to the inherent advantages of both electrochemical sensing and usage of paper as a suitable substrate for POC testing platforms. Even though general aspects of ePADs such as applications and fabrication techniques, have already been reviewed multiple times in the literature, herein, we intend to provide a critical engineering insight into the area of ePADs by focusing particularly on the practical strategies utilized to enhance their analytical performance (i.e. sensitivity), while maintaining the desired simplicity and efficiency intact. Basically, the discussed strategies are driven by considering the parameters potentially affecting the generated electrochemical signal in the ePADs. Some of these parameters include the type of filter paper, electrode fabrication methods, electrode materials, fluid flow patterns, etc. Besides, the limitations and challenges associated with the development of ePADs are discussed, and further insights and directions for future research in this field are proposed.
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http://dx.doi.org/10.1016/j.bios.2020.112506DOI Listing
November 2020

Quantitative determination of trace phenazopyridine in human urine samples by hyphenation of dispersive solid-phase extraction and liquid-phase microextraction followed by gas chromatography/mass spectrometry analysis.

J Sep Sci 2020 Jul 4;43(14):2897-2904. Epub 2020 Jun 4.

Department of Analytical Chemistry, Faculty of Chemistry, K. N. Toosi University of Technology, Tehran, Iran.

Magnetic dispersive solid-phase extraction followed by dispersive liquid-liquid microextraction coupled with gas chromatography/mass spectrometry was applied for the quantitative analysis of phenazopyridine in urinary samples. Magnetic dispersive solid-phase extraction was carried out using magnetic graphene oxide nanoparticles modified by poly(thiophene-pyrrole) copolymer. The eluting solvent of this step was used as the disperser solvent for the dispersive liquid-liquid microextraction procedure. To reach the maximum efficiency of the method, effective parameters including sorbent amount, adsorption time, type and volume of disperser and extraction solvents, pH of the sample solution, and ionic strength as well as desorption time, and approach were optimized, separately. Characterization of the synthesized sorbent was studied by utilizing infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray analysis. Calibration curve was linear in the range of 0.5-250 ng/mL (R  = 0.9988) with limits of detection and quantification of 0.1 and 0.5 ng/mL, respectively. Intra- and interday precisions (RSD%, n = 3) of the method were in the range of 4.6-5.4% and 4.0-5.5%, respectively, at three different concentration levels. Under the optimal condition, this method was successfully applied for the determination of phenazopyridine in human urine samples. The relative recoveries were obtained in the range of 85.0-89.0%.
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http://dx.doi.org/10.1002/jssc.202000055DOI Listing
July 2020

Spin-column micro-solid phase extraction of chlorophenols using MFU-4l metal-organic framework.

Mikrochim Acta 2019 12 10;187(1):39. Epub 2019 Dec 10.

Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran.

A novel metal-organic framework called MFU-4 l was synthesized from ZnCl and 1H-1,2,3-triazolo[4,5-b][4',5'-i])dibenzo[1,4]dioxin. MFU-4 l was characterized and is shown to be a viable sorbent for spin-column micro-solid phase extraction of 4-chlorophenol, 2,3-dichlorophenol, 2,4-dichlorophenol, and 2,4,6-trichlorophenol. Following extraction and elution with methanol, the chlorophenols were quantified by a GC-MS instrument. Various parameters affecting adsorption and desorption were optimized by the one variable at-a-time method. The main feature of the utilized metal-organic framework is its outstanding performance in ultratrace extraction of the target analytes due to the different amino groups existed in the linker structure. Under optimal conditions, the calibration plots are linear in the 0.5-400 μg kg concentration range for water samples, and from 1.0-400 μg kg for soil samples. The respective limits of detection are 0.10 and 0.50 μg kg-1 for water and soil samples, respectively. On top of that, limits of detections are lower than 0.10 and 0.50 μg Kg for water and soil samples, respectively. Inter-day and intra-day relative standard deviations were in the range of 4.4-7.8% for the selected chlorophenols. Preconcentration factors are in the range of 26.3-29.6 for aqueous samples. The method was used to analyze soil and environmental water samples. Graphical abstractSchematic representation of spin-column micro-solid phase extraction of chlorophenols using the MFU-4 l metal-organic framework.
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http://dx.doi.org/10.1007/s00604-019-4023-3DOI Listing
December 2019

Synthesis and characterization of polyamide-graphene oxide-polypyrrole electrospun nanofibers for spin-column micro solid phase extraction of parabens in milk samples.

J Chromatogr A 2019 Aug 8;1599:25-34. Epub 2019 Apr 8.

Department of Chemistry, Tarbiat Modares University, Tehran, Iran.

In the present study, an electrospun composite of polyamide-graphene oxide-polypyrrole was synthesized. The characterization of the synthesized material was accomplished using field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FT-IR). FESEM images showed uniform and beadles nanofibers. The composite was employed as a novel sorbent for spin-column micro solid phase extraction to determine parabens in milk samples. Addition of graphene oxide and polypyrrole into the polymeric network of polyamide significantly improves the extraction efficiency of the electrospun sorbent due to providing the possibility of various interactions with the target analytes such as hydrogen bonding, hydrophobic and π-π stacking. All effective parameters on the efficiency of both adsorption and desorption steps were optimized. These parameters were pH of sample solution (5.0), sorbent amount (20 mg), type and volume of desorption solvent (200 μL of methanol), number of cycles (7 and 14) and centrifugation speed (600 and 500 rpm) of both adsorption and desorption steps. Under the optimal conditions, the calibration plots were linear within the range of 10-1000, 15-1000, and 20-1000 ng mL for methyl paraben, ethyl paraben and propyl paraben, respectively. Limits of detection were obtained lower than 7.0 ng mL by HPLC-UV. Intra- and inter-assay relative standard deviations were less than 8.6% and 5.8%, respectively. Finally, the method was successfully applied for determination of parabens in some milk samples and good recoveries were obtained within the range of 81.7-97.8%. The results demonstrated good efficiency of the synthesized electrospun composite nanofibers as the packing material for spin-column micro solid phase extraction.
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http://dx.doi.org/10.1016/j.chroma.2019.04.014DOI Listing
August 2019

A promising design of microfluidic electromembrane extraction coupled with sensitive colorimetric detection for colorless compounds based on quantum dots fluorescence.

Talanta 2019 Mar 18;194:298-307. Epub 2018 Oct 18.

Department of Chemistry, Faculty of Sciences, Tarbiat Modares University, Tehran, Iran.

In the present study, a microfluidic platform was exploited for electromembrane extraction. For device integration as a lab-on-a-chip system, the detection step was carried out by a colorimetric method based on fluorescence quenching of quantum dots. The model analyte was transferred under a pulsed applied electrical field across a polypropylene membrane, impregnated with 1-Octanol, into a final aqueous acceptor phase. The obtained acceptor phase was added into a solution containing CdTe quantum dots. Quenching of the quantum dots was tracked by analyzing the main three color components of red, green, and blue in different concentration levels of the analyte. All effective parameters on the extraction efficiency, fluorescence detection, and synthesis of quantum dots were optimized. Under the optimal conditions, the detection was accomplished by three different detection methods including HPLC-UV, spectrofluorometric detection, as well as colorimetry detection via a smartphone. Calibration curves were linear in the range of 2.0-500 µg L for LC-UV, 30-2500 µg L for fluorescence detection, and 2.5-20 µg mL for image analysis. Inter- and intra-assay relative standard deviations were less than 10.1% in all detection modes.
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http://dx.doi.org/10.1016/j.talanta.2018.10.046DOI Listing
March 2019

Simultaneous extraction of acidic and basic drugs via on-chip electromembrane extraction using a single-compartment microfluidic device.

Analyst 2019 Feb;144(4):1159-1166

Department of Chemistry, Faculty of Sciences, Tarbiat Modares University, P.O. Box: 14115-175, Tehran, Iran.

In this study, a new chip was designed for simultaneous extraction of acidic and basic drugs by a single chamber on-chip electromembrane extraction (CEME) followed by high performance liquid chromatography. Diclofenac (DIC) and nalmefene (NAL) were selected as acidic and basic model analytes, respectively. In this device, simultaneous extraction of the analytes was carried out using a single compartment. The chip was composed of three PMMA (polymethyl methacrylate) parts with sandwiched structures and carved spiral microfluidic channels in each part. The middle part was cut and an "M" pattern provided interfaces for contact between the sample solution flow and two porous polypropylene sheets on both sides. Two other parts had the same spiral channels dedicated to the corresponding acceptor phases of the acidic and basic analytes and were located at both sides. Each polypropylene sheet was impregnated with the appropriate organic solvent for the acidic and basic analytes. Two platinum electrodes connected to a power supply were mounted at the bottom of the acceptor channels. These electrodes provided the electrical fields across SLMs to extract the analytes from a single sample flow. When the extraction was completed, the acceptor solutions were collected, mixed, and then injected into the chromatographic system. The effective parameters on the extraction efficiency were investigated and optimized. Under the optimal conditions, the calibration curves were linear in the range of 9.0-500 μg L-1 for NAL and 11.0-500 μg L-1 for DIC with the coefficient of determination (R2) higher than 0.9913. The relative standard deviations (RSD%) based on five replicate measurements were less than 6.3%. LOD values were 4.0 and 3.0 μg L-1 for DIC and NAL, respectively. Finally, the method was successfully applied to determine DIC and NAL in the human urine samples and satisfactory results were obtained (recovery ≥90).
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http://dx.doi.org/10.1039/c8an01668bDOI Listing
February 2019

Approach for Downscaling of Electromembrane Extraction as a Lab on-a-Chip Device Followed by Sensitive Red-Green-Blue Detection.

Anal Chem 2018 07 29;90(14):8478-8486. Epub 2018 Jun 29.

Department of Chemistry , Abdul Wali Khan University , Mardan , Khyber Pakhtunkhwa Pakistan , 23200.

A design of electromembrane extraction (EME) as a lab on-a-chip device was proposed for the extraction and determination of phenazopyridine as the model analyte. The extraction procedure was accomplished by coupling EME and packing a sorbent. The analyte was extracted under the applied electrical field across a membrane sheet impregnated by nitrophenyl octylether (NPOE) into an acceptor phase. It was followed by the absorption of the analyte on strong cation exchanger as a sorbent. The designed chip contained separate spiral channels for donor and acceptor phases featuring embedded platinum electrodes to enhance extraction efficiency. The selected donor and acceptor phases were 0 mM HCl and 100 mM HCl, respectively. The on-chip electromembrane extraction was carried out under the voltage level of 70 V for 50 min. The analysis was carried out by two modes of a simple red-green-blue (RGB) image analysis tool and a conventional HPLC-UV system. After the absorption of the analyte on the solid phase, its color changed and a digital picture of the sorbent was taken for the RGB analysis. The effective parameters on the performance of the chip device, comprising the EME and solid phase microextraction steps, were distinguished and optimized. The accumulation of the analyte on the solid phase showed excellent sensitivity and a limit of detection (LOD) lower than 1.0 μg L achieved by an image analysis using a smartphone. This device also offered acceptable intra- and interassay RSD% (<10%). The calibration curves were linear within the range of 10-1000 μg L and 30-1000 μg L ( r > 0.9969) for HPLC-UV and RGB analysis, respectively. To investigate the applicability of the method in complicated matrixes, urine samples of patients being treated with phenazopyridine were analyzed.
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http://dx.doi.org/10.1021/acs.analchem.8b01224DOI Listing
July 2018

Electromembrane extraction of biogenic amines in food samples by a microfluidic-chip system followed by dabsyl derivatization prior to high performance liquid chromatography analysis.

J Chromatogr A 2018 Jun 23;1556:21-28. Epub 2018 Apr 23.

Faculty of Food Industry and Agriculture, Department of Food Science & Technology, Standard Research Institute (SRI), Karaj, 31745-139, Iran.

In the present research, an on-chip electromembrane extraction coupled with high performance liquid chromatography was developed for monitoring the trace levels of biogenic amines (BAs), including histamine, tryptamine, putrescine, cadaverine and spermidine in food samples. A porous polypropylene sheet membrane impregnated with an organic solvent was placed between the two parts of the chip device to separate the channels. Two platinum electrodes were mounted at the bottom of these channels, which were connected to a power supply, providing the electrical driving force for migration of ionized analytes from the sample solution through the porous sheet membrane into the acceptor phase. BAs were extracted from 2 mL aqueous sample solutions at neutral pH into 50 μL of acidified (HCl 90 mM) acceptor solution. Supported liquid membrane including NPOE containing 10% DEHP was used to ensure efficient extraction. Low voltage of 40 V was applied over the SLMs during extraction time. The influences of fundamental parameters affecting the transport of BAs were optimized. Under the optimized conditions, the relative standard deviations based on four replicate measurements were less than 8.0% and limit of detections were in range of 3.0-8.0 μg L. Finally, the method was successfully applied to determinate BAs in the food samples and satisfactory results (recovery > 95.6) were obtained.
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http://dx.doi.org/10.1016/j.chroma.2018.04.046DOI Listing
June 2018

Quantitative analysis of clonidine and ephedrine by a microfluidic system: On-chip electromembrane extraction followed by high performance liquid chromatography.

J Chromatogr B Analyt Technol Biomed Life Sci 2017 Nov 2;1068-1069:313-321. Epub 2017 Nov 2.

Department of Chemistry, Faculty of Sciences, Tarbiat Modares University, P.O. Box: 14115-175, Tehran, Iran.

In this work, a microfluidic device was developed for on-chip electromembrane extraction of trace amounts of ephedrine (EPH) and clonidine (CLO) in human urine and plasma samples followed by HPLC-UV analysis. Two polymethylmethacrylate plates were used as substrates and a microchannel was carved in each plate. The microchannel channel on the underneath plate provided the flow pass of the sample solution and the one on the upper plate dedicated to a compartment for the stagnant acceptor phase. A piece of polypropylene sheet was impregnated by an organic solvent and mounted between the two parts of the chip device. An electrical field, across the porous sheet, was created by two embedded platinum electrodes placed in the bottom of the channels which were connected to a power supply. The analytes were converted to their ionized form, passed through the supported liquid membrane, and then extracted into the acceptor phase by the applied voltage. All the effective parameters including the type of the SLM, the SLM composition, pH of donor and acceptor phases, and the quantity of the applied voltage were evaluated and optimized. Several organic solvents were evaluated as the SLM to assess the effect of SLM composition. Other parameters were optimized by a central composite design. Under the optimal conditions of voltage of 74V, flow rate of 28μLmin, 100 and 20mM HCl as acceptor and donor phase composition, respectively, the calibration curves were plotted for both analytes. The limits of detection were less than 7.0 and 11μgL in urine and plasma, respectively. The linear dynamic ranges were within the range of 10-450 and 25-500μgL (r˃0.9969) for CLO, and within the range of 20-450 and 30-500μgL (r˃0.9907) for EPH in urine and plasma, respectively. To examine the capability of the method, real biological samples were analyzed. The results represented a high accuracy in the quantitative analysis of the analytes with relative recoveries within the range of 94.6-105.2% and acceptable repeatability with relative standard deviations lower than 5.1%.
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http://dx.doi.org/10.1016/j.jchromb.2017.10.062DOI Listing
November 2017