29,957 results match your criteria electrostatic interactions


Delivery of curcumin using a zein-xanthan gum nanocomplex: Fabrication, characterization, and in vitro release properties.

Colloids Surf B Biointerfaces 2021 May 10;204:111827. Epub 2021 May 10.

School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan, 316022, PR China. Electronic address:

This study aimed to use xanthan gum as a stabilizer to improve the stability of zein nanoparticles. Zein-xanthan gum composite nanoparticles were prepared via anti-solvent precipitation at pH 4.0. Read More

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Impact of PIP2 Lipids, Force Field Parameters, and Mutational Analysis on the Binding of the Osh4's α-α Domain.

J Phys Chem B 2021 May 13. Epub 2021 May 13.

Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, United States.

All-atom molecular dynamics simulations are used with the highly mobile membrane mimetic method to study the α-α peptide of the critical yeast Osh4 peripheral membrane protein. This research focuses on the impact of 1-palmitoyl-2-oleoyl--glycero-phosphatidylinoside 4,5-bisphosphate (PIP2) lipids and 1-palmitoyl-2-oleoyl--glycero-3-phospho-l-serine on the protein's ability to bind to the membrane. Details of the binding mechanism are described qualitatively and quantitatively by measuring the position of the deepest residues, angle of the peptide during binding, root mean square deviation of the atomic positions within the peptide, and interaction energy, while changing variables, such as the force field used and the presence of the PIP2 lipids. Read More

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Asp149 and Asp152 in chicken and human ANP32A play an essential role in the interaction with influenza viral polymerase.

FASEB J 2021 Jun;35(6):e21630

Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea.

The acidic nuclear phosphoprotein 32 family member A (ANP32A) is a cellular host factor that determines the host tropism of the viral polymerase (vPol) of avian influenza viruses (AIVs). Compared with human ANP32A (hANP32A), chicken ANP32A contains an additional 33 amino acid residues (176-208) duplicated from amino acid residues 149-175 (27 residues), suggesting that these residues could be involved in increasing vPol activity by strengthening interactions between ANP32A and vPol. However, the molecular interactions and functional roles of the 27 residues within hANP32A during AIV vPol activity remain unclear. Read More

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Polyelectrolyte Multi-Layered Griseofulvin Nanoparticles: Conventional versus Continuous Layer-by-Layer Fabrication.

J Nanosci Nanotechnol 2021 Nov;21(11):5611-5621

School of Cancer and Pharmaceutical Science, Institute of Pharmaceutical Science, King's College London, Franklin-Wilkins Building, 150 Stamford street, London SE1 9NH, United Kingdom.

Polyelectrolyte multilayers are promising drug carriers with potential applications in the delivery of poorly soluble drugs. Furthermore, the polyelectrolyte multilayer contributes towards electrostatic interactions, which enhances the physical and chemical stability of colloids when compared to those prepared by other approaches. The aim of this work was to generate a polyelectrolyte multilayer on well characterised nanoparticles of the poorly water-soluble drug, griseofulvin. Read More

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November 2021

Bioelectronic Measurement of Target Engagement to a Membrane-Bound Transporter.

SLAS Discov 2021 May 12:24725552211013067. Epub 2021 May 12.

Discovery Technologies, Amgen Research, South San Francisco, CA, USA.

The ability to detect and characterize drug binding to a target protein is of high priority in drug discovery research. However, there are inherent challenges when the target of interest is an integral membrane protein (IMP). Assuming successful purification of the IMP, traditional approaches for measuring binding such as surface plasmon resonance (SPR) and fluorescence resonance energy transfer (FRET) have been proven valuable. Read More

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Characterization and comparison of mixed-mode and reversed-phase columns; interaction abilities and applicability for peptide separation.

J Chromatogr A 2021 Apr 27;1648:462182. Epub 2021 Apr 27.

Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova 8, Prague 12843, Czech Republic. Electronic address:

In this work, two mixed-mode columns from a different manufacturers and one marketed as a reversed-phase column were characterized and compared in the terms of their interaction abilities, retentivity, peak symmetry, and applicability for peptide separation. All the tested columns contain octadecyl ligand and positively charged modifier, i.e. Read More

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Critical Interactions Between the SARS-CoV-2 Spike Glycoprotein and the Human ACE2 Receptor.

J Phys Chem B 2021 May 12. Epub 2021 May 12.

Department of Mechanical Engineering, Istanbul Technical University (ITU), 34437 Istanbul, Turkey.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects human cells by binding its spike (S) glycoproteins to angiotensin-converting enzyme 2 (ACE2) receptors and causes the coronavirus disease 2019 (COVID-19). Therapeutic approaches to prevent SARS-CoV-2 infection are mostly focused on blocking S-ACE2 binding, but critical residues that stabilize this interaction are not well understood. By performing all-atom molecular dynamics (MD) simulations, we identified an extended network of salt bridges, hydrophobic and electrostatic interactions, and hydrogen bonds between the receptor-binding domain (RBD) of the S protein and ACE2. Read More

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Benchmarking London dispersion corrected density functional theory for noncovalent ion-π interactions.

Phys Chem Chem Phys 2021 May 12. Epub 2021 May 12.

Mulliken Center for Theoretical Chemistry, Institute of Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115 Bonn, Germany.

The strongly attractive noncovalent interactions of charged atoms or molecules with π-systems are important binding motifs in many chemical and biological systems. These so-called ion-π interactions play a major role in enzymes, molecular recognition, and for the structure of proteins. In this work, a molecular test set termed IONPI19 is compiled for inter- and intramolecular ion-π interactions, which is well balanced between anionic and cationic systems. Read More

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Synthesis, molecular docking, and in silico ADMET studies of 4-benzyl-1-(2,4,6-trimethyl-benzyl)-piperidine: Potential Inhibitor of SARS-CoV2.

Bioorg Chem 2021 May 5;112:104967. Epub 2021 May 5.

Department of Chemistry, Texas A&M University, College Station, TX 77842, USA. Electronic address:

Nowadays, over 200 countries face a wellbeing emergency because of epidemiological disease COVID-19 caused by the SARS-CoV-2 virus. It will cause a very high effect on the world's economy and the worldwide health sector. The present work is an investigation of the newly synthesized 4-benzyl-1-(2,4,6-trimethyl-benzyl)-piperidine (M1BZP) molecule's inhibitory potential against important protein targets of SARS-CoV-2 using computational approaches. Read More

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Salt-dependent passive adsorption of IgG1κ-type monoclonal antibodies on hydrophobic microparticles.

Biophys Chem 2021 May 6;275:106609. Epub 2021 May 6.

Center for Interdisciplinary Biosciences, Technology and Innovation Park, P.J. Šafárik University, Trieda SNP 1, 040 11 Košice, Slovakia. Electronic address:

Understanding how antibodies adsorb on solid surfaces is essential for developing effective approaches to control this process. In this study, passive adsorptions on the hydrophobic solid surface of a polystyrene microparticle (MP) of two highly similar IgG1 κ-type monoclonal antibodies (mAbs), rituximab, and trastuzumab, were examined in the presence of Hofmeister salts. Except of kosmotropic salts, the screening of electrostatic interactions using salts reduces the passive adsorption of mAbs on MP. Read More

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Binding Mechanisms of Amyloid-like Peptides to Lipid Bilayers and Effects of Divalent Cations.

ACS Chem Neurosci 2021 May 11. Epub 2021 May 11.

Department of Physics, New Jersey Institute of Technology, Newark, New Jersey 07102-1982, United States.

In several neurodegenerative diseases, cell toxicity can emerge from damage produced by amyloid aggregates to lipid membranes. The details accounting for this damage are poorly understood including how individual amyloid peptides interact with phospholipid membranes before aggregation. Here, we use all-atom molecular dynamics simulations to investigate the molecular mechanisms accounting for amyloid-membrane interactions and the role played by calcium ions in this interaction. Read More

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Green surfactant-dendrimer aggreplexes: An ingenious way to launch dual attack on arch-enemy cancer.

Colloids Surf B Biointerfaces 2021 May 5;204:111821. Epub 2021 May 5.

Centre for Pharmaceutical Nanotechnology, Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Mohali, 160062, Punjab, India. Electronic address:

Combination therapy, which combines anti-cancer drugs with different oligonucleotides, have shown potential in cancer treatment. However, delivering a hydrophobic anti-cancer drug and a hydrophilic oligonucleotide simultaneously is a herculean task. This study takes advantage of interactions between histidine-lauric acid-based green surfactant and poly(amidoamine) dendrimers to achieve this aim. Read More

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Kappa-carrageenan enhances the gelation and structural changes of egg yolk via electrostatic interactions with yolk protein.

Food Chem 2021 Apr 28;360:129972. Epub 2021 Apr 28.

Department of Food Science and Technology, National University of Singapore, 117542, Singapore; National University of Singapore (Suzhou) Research Institute, 377 Lin Quan Street, Suzhou Industrial Park, Suzhou, Jiangsu 215123, PR China. Electronic address:

The effect of κ-carrageenan (κ-C) on yolk over heat-induced gelation at natural yolk pH (6.2) and natural whole egg pH (7.5) was studied. Read More

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Design, synthesis, structural and molecular characterization, toxicity, psychotropic activity and molecular docking evaluation of a novel phenytoin derivative: 3-decyl-5,5-diphenylimidazolidine-2,4-dione.

J Biomol Struct Dyn 2021 May 10:1-18. Epub 2021 May 10.

Laboratory of Medicinal Chemistry, Drug Sciences Research Center, Faculty of Medicine and Pharmacy, Mohammed V University in Rabat, Rabat, Morocco.

The hydantoin scaffold is of substantial importance and it is commonly used in drug discovery. Herein, we report the synthesis of a novel phenytoine (a hydantoin derivative) with high yield by the reaction of phenytoin with 1-bromodecyl agent. Namely, 3-decyl-5,5- diphenylimidazolidine-2,4-dione (3DDID). Read More

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Accurate Atom-Dipole Interaction Model for Prediction of Electro-optical Properties: From van der Waals Aggregates to Covalently Bonded Clusters.

J Phys Chem A 2021 May 10. Epub 2021 May 10.

Departamento de Química, Universidade Federal de Minas Gerais, Av. Pres. Antônio Carlos 6627, 31270-901 Belo Horizonte, MG, Brazil.

This work aims at the accurate estimation of the electro-optical properties of atoms and functional groups in organic crystals. A better understanding of the nature of building blocks and the way they interact with each other enables more efficient prediction of self-assembly, and thus physical properties in condensed matter. We propose a modified version of an atom-dipole interaction model that is based on atomic dipole moments calculated from the quantum theory of atoms in molecules. Read More

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Ionic Salts@Metal-Organic Frameworks: Remarkable Component to Improve Performance of Fabric Filters to Remove Particulate Matters from Air.

ACS Appl Mater Interfaces 2021 May 10. Epub 2021 May 10.

Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu, 41566, Republic of Korea.

The elimination of particulate matters (PMs) from the air is very important for our sustainability. In this study, highly porous metal-organic frameworks (MOFs) like MIL-101 and UiO-67 were first modified, coated onto cotton, and applied in PM removal via filtration. Ionic salts (ISs) like CaCl and LiCl, after loading onto the MOFs, remarkably increased the PM removal efficiency. Read More

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Cadmium Isotope Fractionation during Complexation with Humic Acid.

Environ Sci Technol 2021 May 10. Epub 2021 May 10.

Department of Environmental Geosciences, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 16500 Prague-Suchdol, Czech Republic.

Cadmium (Cd) isotopes are known to fractionate during complexation with various environmentally relevant surfaces and ligands. Our results, which were obtained using (i) batch experiments at different Cd concentrations, ionic strengths, and pH values, (ii) modeling, and (iii) infrared and X-ray absorption spectroscopies, highlight the preferential enrichment of light Cd isotopes bound to humic acid (HA), leaving the heavier Cd pool preferentially in solution (ΔCd of -0.15 ± 0. Read More

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Elucidating specificity of an allosteric inhibitor WNK476 among WNK isoforms using molecular dynamic simulations.

Chem Biol Drug Des 2021 May 10. Epub 2021 May 10.

Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore-453552, Madhya Pradesh, India.

Specifically targeting the With-No-Lysine (WNK1) kinase, which is implicated in hypertension, renders a significant challenge in discovering competitive inhibitors due to the highly conserved ATP binding pocket. However, an allosteric inhibitor may impart high specificity against the WNK kinase isoforms since it targets the less conserved site and can provide greater efficacy even under high physiological ATP concentration. In the current study, we have investigated the structural and energetic basis of the specificity of the allosteric inhibitor WNK476 against WNK kinase isoforms by combining molecular dynamics simulations and free energy calculations using molecular mechanics Poisson-Boltzmann surface area (MMPBSA). Read More

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Electrosteric stabilization of oil/water emulsions by adsorption of chitosan oligosaccharides-An electrokinetic study.

Authors:
Viktoria Milkova

Carbohydr Polym 2021 Aug 16;265:118072. Epub 2021 Apr 16.

Institute of Physical Chemistry, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria; Institut für Biology und Biotechnologie der Pflanzen, Westfälische Wilhems-Universität Münster, Schlossgarten 3, Münster, 48149, Germany. Electronic address:

The present study was focused on investigation of electrokinetic behaviour of lecithin-stabilized oil/water emulsions in the presence of chitosan oligosaccharides (COS). The oligosaccharides give unique opportunity for precisely characterization of the properties of chitosan as a function of the degree of acetylation (DA) and degree of polymerization (DP) of the polymer. For the study were chosen well characterized ultra pure COS molecules with completely acetylated monomers and mixture of COS molecules with acetylated and deacetylated monomers. Read More

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Albumin-Based LL37 Peptide Nanoparticles as a Sustained Release System against Lung Infection.

ACS Biomater Sci Eng 2021 May 31;7(5):1817-1826. Epub 2020 Aug 31.

Department of Respiratory and Critical Care Medicine, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai 200433, China.

(PA) has emerged as a pressing challenge to pulmonary infection and lung damage. The LL37 peptide is an efficient antimicrobial agent against PA strains, but its application is limited because of fast clearance , biosafety concerns, and low bioavailability. Thus, an albumin-based nanodrug delivery system with reduction sensitivity was developed by forming intermolecular disulfide bonds to increase LL37 performance against PA. Read More

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Revealing the dynamic adsorption and diffusion of peptide amphiphile on supported lipid bilayer by single molecule experiment and simulation.

Colloids Surf B Biointerfaces 2021 May 1;204:111809. Epub 2021 May 1.

Key Laboratory of Materials Chemistry for Energy Conversion and Storage (HUST) of Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China.

Dynamic adsorption and diffusion of peptide amphiphiles (PAs) with different numbers of alkyl tails on supported lipid bilayers (SLBs) were investigated by single molecule tracking experiment and molecule dynamic simulation. Experimental results show two distinct populations of PAs with different residence time. Residence time of adsorbed PAs increases with the increase of the alkyl tails, whereas diffusion coefficient monotonically decreases with rising the number of alkyl tails and also decreases with increasing the mobility of SLBs. Read More

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Efficient removal of tetracycline by a hierarchically porous ZIF-8 metal organic framework.

Environ Res 2021 May 7;198:111254. Epub 2021 May 7.

State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, 610065, China; College of Water Resource and Hydropower, Sichuan University, Chengdu, 610065, China.

Most reported metal organic frameworks (MOFs) have microporous structures and defective active sites, limiting their practical application to macromolecular substances. A hierarchical porous zeolitic imidazolate framework-8 (ZIF-8) was prepared using poly(diallyldimethylammonium chloride) (PDDA) as a structure-directing agent under facile "aqueous room-temperature" conditions to increase the mass transfer and adsorption capacity tetracycline hydrochloride (TCH). The ZIF-8 pore structure and morphology were synchronously tuned by controlling the PDDA molecular weight and dosage. Read More

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The different interactions of two anticancer drugs with bovine serum albumin based on multi-spectrum method combined with molecular dynamics simulations.

Spectrochim Acta A Mol Biomol Spectrosc 2021 May 6;259:119809. Epub 2021 May 6.

College of Chemistry and Chemical Engineering, Qiqihar University, No. 42, Wenhua Street, Qiqihar, PR China.

Paclitaxel is the best natural anticancer drug and artemisinin also has anticancer effect. In this study, the interactions between BSA and these two drugs were determined in PBS (pH 7.40) by multi-spectroscopic method and molecular dynamics (MD) simulations. Read More

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Synthesis of orange-emissive silicon nanoparticles as "off-on" fluorescence probe for sensitive and selective detection of l-methionine and copper.

Talanta 2021 Aug 30;231:122369. Epub 2021 Mar 30.

CAS Key Laboratory of Chemistry of Northwestern Plant Resources, Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences (CAS), Lanzhou, 730000, PR China. Electronic address:

Fluorescent silicon nanoparticles (Si NPs) are of great interest as they are free of heavy ions. However, most of Si NPs exhibit blue or green emission, while orange or red-emitting Si NPs are required for an extensive range of applications. Copper ion (Cu) and l-methionine (L-Met) detection is critically valuable point since their abnormal level is an indicator of various diseases. Read More

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Chemical stabilization of γ-polyglutamate by chitosan and the effect of co-solvents on the stability.

Biophys Chem 2021 Apr 30;275:106605. Epub 2021 Apr 30.

Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, 8159358686 Isfahan, Iran.

In protein-based formulations, conformational distortions and attractive interactions may cause insoluble and undesired aggregates. In the case of ionic peptides, including cationic or anionic, commonly electrostatic interactions are the main factors that control structure assembling. In this study, it was proposed that grafting of chitosan (CS) to γ-polyglutamic acid (γ-PGA) might exhibit much strong inhibiting effect on the formation of protein aggregates due to multiple amino groups and hydrophilic properties. Read More

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Molecular interaction between pectin and catechin/procyanidin in simulative juice model: Insights from spectroscopic, morphology, and antioxidant activity.

J Food Sci 2021 May 7. Epub 2021 May 7.

Shanghai Food Safety and Engineering Technology Research Center, Bor S. Luh Food Safety Research Center, Key Lab of Urban Agriculture Ministry of Agriculture, School of Agriculture & Biology, Shanghai Jiao Tong University, Shanghai, China.

The interactions between polysaccharides and phenolics in foods affect their physicochemical properties and bioactivity. Pectin and catechin/procyanidin present in plants ubiquitously and attracting more attentions for the potential health benefits. This work investigates the interactions between high methoxyl pectin and catechin/procyanidin in a simulative juice model using multiple microscopic and spectroscopic approaches and their influences on the antioxidant activity of phenolics were evaluated in the Caco-2 cells model. Read More

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Effect of pH adjustment and ratio of oppositely charged polymers on the mechanistic performance and sustained release of volatile perfume in interpolyelectrolyte complex microcapsules.

Int J Pharm 2021 May 4:120672. Epub 2021 May 4.

College of Pharmacy, Ajou University, Suwon 16499, Republic of Korea. Electronic address:

In this study, volatile perfume was encapsulated in microcapsules (MCs) via interpolyelectrolyte complexes (IPECs) of oppositely charged polymers, with high encapsulation efficiency, to be delivered in a sustained manner. Positively charged chitosan (CTS) and negatively charged Eudragit® S100 (ES100) were used as eco-friendly biopolymers. Limonene (LMN) was selected as the model perfume. Read More

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Cations Regulate Membrane Attachment and Functionality of DNA Nanostructures.

J Am Chem Soc 2021 May 7. Epub 2021 May 7.

Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom.

The interplay between nucleic acids and lipids underpins several key processes in molecular biology, synthetic biotechnology, vaccine technology, and nanomedicine. These interactions are often electrostatic in nature, and much of their rich phenomenology remains unexplored in view of the chemical diversity of lipids, the heterogeneity of their phases, and the broad range of relevant solvent conditions. Here we unravel the electrostatic interactions between zwitterionic lipid membranes and DNA nanostructures in the presence of physiologically relevant cations, with the purpose of identifying new routes to program DNA-lipid complexation and membrane-active nanodevices. Read More

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The comparison of structure, nature of bond, and electronic transitions in [M(η -Cp)(η -C Me )] (M = Fe , Ru , Os ) hybrids and corresponding metallocenes; a theoretical study.

J Comput Chem 2021 May 7. Epub 2021 May 7.

Department of Chemistry, Faculty of Science, Malayer University, Malayer, Iran.

In this paper, metallocene-fullerene hybrid complexes, [M(η -Cp)(η -C Me )] (M = Fe , Ru , Os ), as well as corresponding classical metallocenes have been studied theoretically at BP86/def2-SVP and M06L/def2-SVP levels of theory. With considering these metal complexes as an ABA' system (B is the central metal ion and A and A' are related η -ligands), the total interaction energies were calculated using common methods, as well as by calculating the interaction energies between the four defined pairs of fragments including A-B, B-A', A-BA', and AB-A'. The resulting data clearly showed that in all complexes there is a strong anticoopertivity between two metal-(η -ligand) bonds. Read More

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Electrochemical immunosensor development based on core-shell high-crystalline graphitic carbon nitride@carbon dots and CdZnS/d-TiCT MXene composite for heart-type fatty acid-binding protein detection.

Mikrochim Acta 2021 May 7;188(6):182. Epub 2021 May 7.

Faculty of Health Sciences, Department of Nutrition and Dietetics, Hasan Kalyoncu University, Gaziantep, Turkey.

Acute myocardial infarction (AMI) is a significant health problem owing to its high mortality rate. Heart-type fatty acid-binding protein (h-FABP) is an important biomarker in the diagnosis of AMI. In this work, an electrochemical h-FABP immunosensor was developed based on CdZnS/d-TiCT MXene (MXene: Transition metal carbide or nitride) composite as signal amplificator and core-shell high-crystalline graphitic carbon nitride@carbon dots (hc-g-CN@CDs) as electrochemical sensor platform. Read More

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