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electrochemical impedance Analysis of Biofunctionalized Conducting Polymer-Modified Graphene-CNTs Nanocomposite for Protein Detection

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Nano-Micro Letters 2017年第1期9卷 104-112页

作者： Shobhita Singal Avanish K.Srivastava Rajesh CSIR-National Physical Laboratory Dr.K.S.Krishnan RoadNew Delhi 110012India Academy of Scientific and Innovative Research(AcSIR) CSIR-National Physical LaboratoryDr.K.S.Krishnan RoadNew Delhi 110012India

We report an electrodeposited poly(pyrrole-co-pyrrolepropylic acid) copolymer modified electroactive graphene-carbon nanotubes composite deposited on a glassy carbon electrode to detect the protein antigen(cTnI). The copolymer provides pendant carboxyl groups for the site-specific covalent immobilization of protein antibody, antitroponin I. The hybrid nanocomposite was used as a transducer for biointerfacial impedance sensing for cTnI *** results show that the hybrid exhibits a pseudo capacitive behaviour with a maximum phase angle of 49° near 1 Hz,which is due to the inhomogeneous and porous structure of the hybrid composition. The constant phase element of copolymer is 0.61(n = 0.61), whereas, it is 0.88(n = 0.88) for the hybrid composites, indicating a comparatively homogeneous microstructure after biomolecular functionalization. The transducer shows a linear change in charge transfer characteristic(R_(et)) on cTnI immunoreaction for spiked human serum in the concentration range of 1.0 pg mL^(-1)–10.0 ng mL^(-1). The sensitivity of the transducer is 167.8 ± 14.2 Ω cm^2 per decade, and it also exhibits high specificity and good reproducibility.

关键词： Conducting polymer Graphene Carbon nanotube Hybrid Transducer Protein antigen cTnI electrochemical impedance

An improvement to the data processing course of electrochemical impedance technique

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Journal of University of Science and Technology Beijing 2003年第6期10卷 57-60页

作者： Yinglv Jiang, Yinshun Wu, and Hong ChuCorrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083, China Corrosion and Protection Ctr. Univ. of Sci. and Technol. Beijing Beijing 100083 China

For some electrochemical systems the traditional data processing methods cannot be met, so it is necessary to develop a new method to deal with these problems. When processingthe electrochemical AC impedance data of titanium alloy TA12 in 3 percent NaCl solution (at freecorrosion potential, room temperature) a new method is developed which can detach the information ofthe interface resistance demonstrably from the interface capacitance. The results show that theinterface resistance and capacitance are all functions of frequency. And the AC impedance of theresistance and capacitance obey the following relations: C(f) = 10^(4.01982) f^(-0.9292), R(f)=10^(4.80011) (f+0.008)^(-0.90897), which is completely different from the traditional conceptionthat the interface resistance and capacitance are constants. And this phenomenon is ubiquitous intitanium alloys according to the study. So perhaps it is an innate characteristic of interface.

关键词： titanium alloy electrochemical impedance corrosion

A microfluidic biosensor for rapid detection of Salmonella typhimurium based on magnetic separation,enzymatic catalysis and electrochemical impedance analysis

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Chinese Chemical Letters 2022年第6期33卷 3156-3160页

作者： Yingjia Liu Dong Jiang Siyuan Wang Gaozhe Cai Li Xue Yanbin Li Ming Liao Jianhan Lin Key Laboratory of Agricultural Information Acquisition Technology Ministry of Agriculture and Rural AffairsChina Agricultural UniversityBeijing 100083China Department of Biological and Agricultural Engineering University of ArkansasFayettevilleAR 72701United States College of Veterinary medicine South China Agricultural UniversityGuangzhou 510642China

Rapid screening of foodborne pathogens is of great significance to ensure food safety.A microfluidic biosensor based on immunomagnetic separation,enzyme catalysis and electrochemical impedance analysis was developed for rapid and sensitive detection of ***,the bacterial sample,the magnetic nanoparticles(MNPs)modified with capture antibodies,and the enzymatic probes modified with detection antibodies and glucose oxidase(GOx)were simultaneously injected into the microfluidic chip,followed by mixing and incubation to form MNP-bacteria-probe sandwich ***,glucose with high impedance was injected into the chip and catalyzed by the GOx on the complexes into hydrogen peroxide with high impedance and gluconic acid with low impedance,which was finally measured using the low-cost interdigitated microelectrode and the electrochemical impedance analyzer to determine the target *** the optimal conditions,this biosensor could quantitatively detect *** at the concentrations from 1.6×10^(2) CFU/m L to 1.6×10^(6) CFU/m L in 1 h with the low detection limit of 73 CFU/m ***,this biosensor was demonstrated with good feasibility for practical applications by detecting the *** spiked chicken meat samples.

关键词： Biosensor Microfluidic chip electrochemical impedance Interdigitated microelectrode Foodborne bacteria

Study on surface acid-base property of carboxylic acid-terminated self-assembled monolayers by cyclic voltammetry and electrochemical impedance spectroscopy

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Chinese Journal of Chemistry 2000年第6期18卷 863-867页

作者：罗立强程志亮杨秀荣汪尔康 Laboratory of Electroanalytical Chemistry and National Analytical Research Center of Electrochemistry and Spectroscopy Changchun Institute of Applied Chemistry Chinese Academy of Sciences ChangchunJilin 130022 China

Cyclic voltammetry and electrochemical impedance spectroscopy were used to study the surface acid-base property of carboxylic acid-terminated self-assembled monolayers (SAMs). A carboxylic acid-terminated thiol, such as thioctic acid (l,2-dithiolane-3-pentanoic acid), was self-assembled on gold electrodes. Electron transfer between the bulk solution and the SAM modified electrode was studied at different pH using Fe(CN)63? as a probe. The surface pKa. of thioctic acid was determined by cyclic voltammetry and electrochemical impedance spectroscopy to be 5.6 ± 0.1 and 5.8 ± 0.1, respectively. The method is compared with other methods of monolayer pKa measurement.

关键词： Surface pKa self-assembled monolayer cyclic voltammetry electrochemical impedance

Comparative investigation on copper atmospheric corrosion by electrochemical impedance and electrical resistance sensors

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Transactions of Nonferrous Metals Society of China 2021年第10期31卷 3024-3038页

作者： Shan WAN Bo-kai LIAO Ze-hua DONG Xing-peng GUO School of Chemistry and Chemical Engineering Guangzhou UniversityGuangzhou 510006China Hubei Key Laboratory of Material Chemistry and Service Failure School of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan 430074China

electrochemical impedance(EIS)and thin electrical resistance(ER)sensors were invented for atmospheric corrosion measurement of copper(Cu)during cyclic wetting−drying/high−low temperature tests and field exposure ***-month field exposure results showed that average corrosion rate of Cu measured by ER sensor was well in accordance with that by weight loss *** cyclic wetting−drying test,EIS was proven to reflect sensitively time of wetting and drying on the surface of *** corrosion rate obtained from EIS had a similar tendency to that obtained from ER sensors,the former was more dependent on environmental humidity than the *** relative humidity was low than 60%,corrosion rate of Cu measured by EIS was much lower than that by weight loss method,mainly attributing to the fact that impedance sensor failed to detect corrosion current of interlaced Cu electrodes due to the breakdown of conductive passage composed of absorbed thin liquid film under low humidity ***,ER sensor was proven to be more suitable for atmospheric corrosion monitoring than electrochemical techniques because it could sensitively monitor thickness loss of Cu foil according to the Ohmic law,no matter how dry or wet the sensor surface is.

关键词： atmospheric corrosion copper electrical resistance probe electrochemical impedance in-situ corrosion monitoring

Analysis of electrochemical impedance and XRD spectroscopy for complex self-assembled film on silver

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Journal of Southeast University(English Edition) 2006年第1期22卷 121-124页

作者：王怡红宋伟高李憬葛杰顾宁东南大学生物电子学国家重点实验室南京210096 东南大学化学化工系南京210096

Self-assembled monolayers （SAMs） of （3-mercaptopropy） trimethoxysilane （3-MtrF） chemisorbed on silver surfaces were chemically ＂modified by 1-octadecanethiol to form self-assembled mixed-monolayers （SAMM） and the co-polymer of N-vinylcarbazole and methyl methacrylate ester （to form complex selfassembled film （CSAF））. The oxidation resistance of these barriers on silver surfaces and some influential factors concerned processes were analyzed by electrochemical impedance spectroscopy （EIS） in a 10% NaOH aqueous solution at oxidation potential. X-ray diffraction （XRD） spectroscopy shows that the oxidation occurring on the silver surface may be restrained effectively due to the coating barrier, and CSAF（Ⅱ） is the best one. Studies also reveal that oxide processes of bare silver and a series of modified silver electrodes in a 10% NaOH aqueous solution are of more than two relaxation time constants.

关键词： electrochemical impedance X-ray diffraction complex self-assembled multilayer silver

A Study on a Partially Immersed Gold Electrode Using an electrochemical Quartz Crystal impedance System

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Chinese Chemical Letters 2000年第9期11卷 809-812页

作者： Qing Ji XIE You Yu ZHANG Ming SUN Ling YI Shou Zhuo YAO Chemical Research Institute, Hunan Normal University, Changsha 410081 Chemical Research Institute Hunan Normal University

The electrochemical quartz crystal impedance system (EQCIS) has been used for the study of a partially immersed Au electrode in 0.2 mol/L NaClO4 aqueous solution. The influences of the immersed area and height of the electrode on the EQCIS responses were evaluated, showing the highest response sensitivity to liquid loading at the center of the piezoelectric quartz crystal electrode. The increase in the immersed height of the Au electrode at oxygen reduction potentials during potential cycling was measured by this technique.

关键词： electrochemical quartz crystal impedance system (EQCIS) equivalent circuit parameters electrochemical impedance partially immersed Au electrode

Corrosion resistance of pulsed laser modified AZ31 Mg alloy surfaces

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Journal of Magnesium and Alloys 2022年第3期10卷 819-832页

作者： S.Fajardo L.Miguélez M.A.Arenas J.de Damborenea I.Llorente S.Feliu Department of Surface Engineering Corrosion and DurabilityNational Centre for Metallurgical Research(CENIM-CSIC)Madrid 28040Spain

The effect of laser surface melting on the corrosion resistance of AZ31 Mg alloy in 0.1 M NaCl solution was investigated using different laser processing conditions(energy densities of 14 and 17 J cm^(-2)).Laser treatment induced rough surfaces primarily composed of oxidized species of *** analysis revealed that the surface concentration of Al increased significantly as a consequence of *** impedance spectroscopy showed that the laser treatment remarkably increased the polarization resistance of the AZ31 Mg alloy and induced a passive-like region of about 100 mV,as determined by potentiodynamic *** of the results obtained provide solid evidence that within the immersion times used in this study,LSM treatment increased the corrosion resistance of AZ31 Mg alloy under open circuit conditions and anodic polarization.

关键词： Mg alloys laser surface melting(LSM) electrochemical impedance Potentiodynamic polarization corrosion resistance.

A homogeneous and mechanically stable artificial diffusion layer using rigid-flexible hybrid polymer for high-performance lithium metal batteries

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Journal of Energy Chemistry 2023年第1期76卷 631-638,I0015页

作者： Zhenkang Lin Yuyan Ma Wei Wang Yu He Menghao Wang Jun Tang Cheng Fan Kening Sun Beijing Key Laboratory for Chemical Power Source and Green Catalysis School of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China

Artificial solid electrolyte interphase(SEI) is promising to inhibit uncontrollable lithium dendrites and enable long cycling stability for lithium metal batteries. However, the essential mechanical stability is limited since organic layers generally have low modulus whereas intrinsic brittleness for inorganic ones remains a great concern. Polymer-based SEIs with rigid and flexible chains in adequate mechanical properties are supposed to address this issue. Herein, a homogeneous and mechanically stable diffusion layer is achieved by blending rigid chains of polyphenylene sulfone(PPSU) with flexible chains of poly(vinylidene fluoride)(PVDF) in a hybrid membrane, enabling uniform diffusion and stabilizing the lithium metal anode. The Li||Cu cell with the protected electrode exhibits a long lifetime more than 450 cycles(0.5 m A cm^(-2), 1.0 m A h cm^(-2))(fourfold longer than the control group) with higher average Coulombic efficiency of 98.7%. Enhanced performances are also observed at Li||Li and full cell configurations. The improved performances are attributed to the controlled morphology and stable interphase, according to scanning electron microscopy(SEM) and electrochemical impedance. This research advances the idea of uniform lithium plating and provides a new insight on how to create a homogeneous and mechanically stable diffusion layer using rigid-flexible polymers.

关键词： Lithium metal battery Lithium dendrite Uniform diffusion Rigid-flexible artificial layer electrochemical impedance