电化学葡萄糖传感器

作为电化学生物传感器中最重要的研究内容之一,葡萄糖生物传感器在数十年的发展中取得了巨大进展。本文综述了近年来利用纳米技术设计的新型电化学葡萄糖传感器的主要研究进展,并从纳米材料维度分类进行了讨论。其中,零维纳米材料主要讨论了包括金纳米颗粒、银纳米颗粒以及铜、铂等金属纳米颗粒材料; 一维纳米材料主要讨论了通过模板法制备的金属或金属氧化物纳米线以及单臂或者多壁纳米管材料; 二维纳米材料主要总结了以碳为基础的石墨烯材料和一些片状的金属材料。纳米材料对电化学葡萄糖传感器的影响主要集中在生物相容性、增强检测灵敏度、酶的固定等方面。此外,本文也对电化学葡萄糖传感器的今后发展做了展望。     

Glucose oxidase electrodes of a terpolymer poly(aniline-co-o-anisidine-co-o-toluidine) as biosensors

A simple technique is described for constructing a glucose sensor by the entrapment of glucose oxidase (GOD) in a poly (aniline-co-o-anisidine-co-o-toluidine) [P(A-co-o-A-co-o-T)] thin films, which were electrochemically deposited on a platinum plate in phosphate and acetate buffer. The maximum current response was observed for the said electrodes at pH 5.5 and potential 0.60 V (versus Ag/AgCl). The phosphate buffer gives high stability and fast response as compared to acetate buffer in amperometric measurements.     

Electrochemical and morphological characterization of poly[(R)-(−)-3-(l-pyrrolyl)propyl-N-(3,5-dinitrobenzoyl)-α-phenylglycinate] films deposited on ITO electrodes

Poly[(R)-(–)-3-(l-pyrrolyl)propyl-N-(3,5-dinitrobenzoyl)-α-phenylglycinate] films were deposited on ITO electrodes using potentiodynamic and galvanostatic methods. Polymerization occurred as a charge dependent process at 1.0 V vs. Ag/Ag⁺(CH₃CN) and was not affected by the presence of nitro groups in the monomer. The surface morphology of the film and its electrochemical properties were studied as a function of deposition charge (Q_dep) and deposition method. Film thickness increased in a quasi-linear manner with respect to Q_dep within the range 40–80 mC cm². The galvanostatic method provided easier control of Q_dep compared with potentiodynamic deposition, and produced a more adherent film with homogeneous grain geometry. Cyclic voltammetry revealed a well defined redox couple at the anodic region, attributable to polymer p-doping, and a poorly defined redox pair at the cathodic region, attributable to the reduction of the nitro group.     

An Amperometric Glucose Biosensor Based on Poly (Pyrrole‐2‐Carboxylic Acid)/Glucose Oxidase Biocomposite

A newly developed amperometric glucose biosensor based on graphite rod (GR) working electrode modified with biocomposite consisting of poly (pyrrole‐2‐carboxylic acid) (PCPy) particles and enzyme glucose oxidase (GOx) was investigated. The PCPy particles were synthesized by chemical oxidative polymerization technique using H₂O₂ as initiator of polymerization reaction and modified covalently with the GOx (PCPy‐GOx) after activation of carboxyl groups located on the particles surface with a mixture of N‐(3‐dimethylaminopropyl)‐N′‐ethylcarbodiimide hydrochloride (EDC) and N‐hydroxysuccinimide (NHS). Then the PCPy‐GOx biocomposite was dispersed in a buffer solution containing a certain amount of bovine serum albumin (BSA). The resulting biocomposite suspension was adsorbed the on GR electrode surface with subsequent solvent airing and chemical cross‐linking of the proteins with glutaraldehyde vapour (GR/PCPy‐GOx). It was determined that the current response of the GR/PCPy‐GOx electrodes to glucose measured at +300 mV vs Cl reference electrode was influenced by the duration of the PCPy particles synthesis, pH of the GOx solution used for the PCPy particles modification and the amount of immobilized PCPy‐GOx biocomposite. An optimal pH of buffer solution for operation of the biosensor was found to be 8.0. Detection limit was determined as 0.039 mmol L⁻¹ according signal to noise ratio (S/N: 3). The proposed glucose biosensor was tested in human serum samples.     

Electrochemical polymerization of 1-(4-nitrophenyl)-2,5-di(2-thienyl)-1 H-pyrrole as a novel immobilization platform for microbial sensing

Two types of bacterial biosensor were constructed by immobilization of Gluconobacter oxydans and Pseudomonas fluorescens cells on graphite electrodes modified with the conducting polymer; poly(1-(4-nitrophenyl)-2,5-di(2-thienyl)-1 H-pyrrole) [SNS(NO₂)]. The measurement was based on the respiratory activity of cells estimated by the oxygen consumption at − 0.7 V due to the metabolic activity in the presence of substrate. As well as analytical characterization, the linear detection ranges, effects of electropolymerization time, pH and cell amount were examined by using glucose as the substrate. The linear relationships were observed in the range of 0.25–4.0 mM and 0.2–1.0 mM for G. oxydans and P. fluorescens based sensors, respectively.     

Electrochemical Biosensors for Cancer Biomarker Detection

Cancer is still one of the leading causes of death in the world. There are over 200 types of cancers currently known according to the National Cancer Institute. However, early diagnosis continues to be an important integral part of cancer treatment even though many advances in therapeutics have been made in the past decade. Quick diagnosis and early prevention are critical for the control of the disease status. Biomarkers are commonly indicative of a particular disease process and the cancer biomarkers are also widely used in oncology to help detecting the presence of various carcinomas. The detection of cancer biomarkers plays an important role in clinical diagnoses and evaluation of treatment for patients. Many immunoassay methods are developed for detection of cancer biomarkers. As the detection devices are normally viewed with high sensitivity, simple preparation and rapid response, electrochemical biosensors are increasingly used for the detection of cancer markers. This review describes the status, the latest research and trends of electrochemical sensors in the quantitation of cancer markers in recent years. In particular, the strategy to improve the sensitivities of the electrochemical biosensors by the aid of enzymatic amplification, nanoparticle amplification, ultilization of magnetic microspheres etc. is described herein. At last, we discuss some special features and limitations associated with the described systems that summarize the application and the development prospects of electrochemical immunoassay technology.     

脱氧核糖核酸电化学传感器的原理及其应用

对电化学DNA传感器的组成及其在DNA损伤研究、环境污染监控、病原基因检测、基因疾病诊断和药物机理分析等方面的进行了总结，并对其发展趋势进行了评述。     

Development of Novel Glucose and Pyruvate Biosensors at Poly(Neutral Red) Modified Carbon Film Electrodes. Application to Natural Samples

Amperometric biosensors based on the corresponding oxidase enzyme with poly(neutral red) redox mediator have been developed for the determination of glucose and pyruvate. The enzymes have been immobilized on top of poly(neutral red) modified carbon film electrodes with glutaraldehyde as the cross‐linking agent. The biosensors were characterized by cyclic voltammetry and by electrochemical impedance spectroscopy. The glucose biosensor exhibited a linear response in the range 90 μM to 1.8 mM with a detection limit of 22 μM and the pyruvate biosensor in the range 90 to 600 μM with a detection limit of 34 μM. The relative standard deviations were found to be 2.1% (n=3) and 2.8% (n=4) respectively. The interference effects of various compounds were also studied. The glucose content of several types of wine and the amount of pyruvate in onion and garlic were determined and the results were compared with those obtained by standard spectrophotometric methods.     

Formation of polyaniline/Pt nanoparticle composite films and their electrocatalytic properties

Polyaniline (PANI) thin films modified with platinum nanoparticles have been prepared by several methods, characterised and assessed in terms of electrocatalytic properties. These composite materials have been prepared by the in situ reduction of a platinum salt (K₂PtCl₄) by PANI, in a variety of solvents, resulting in the formation of platinum nanoparticles and clusters of different sizes. The further deposition of platinum clusters at spin cast thin films of PANI/Pt composites from a neutral aqueous solution of K₂PtCl₄ has also been demonstrated. Thin-film electrodes prepared from these materials have been investigated for their electrocatalytic activity by studying hydrazine oxidation and dichromate reduction. The properties of the composite materials have been determined using UV–visible spectroscopy, atomic force microscopy and transmission electron microscopy. The nature of the material formed is strongly dependent on the solvent used to dissolve PANI, the method of preparation of the PANI/Pt solution and the composition of the spin cast thin film before subsequent deposition of platinum from the aqueous solution of K₂PtCl₄.Dedicated to Professor Dr. Alan Bond on the occasion of his 60th birthday.     

电化学DNA生物传感器研究的应用进展*

电化学DNA生物传感器因快速、灵敏、低耗和易于操作等优点在基因序列测定中受到了广泛的关注,已逐渐成为分子生物学和生物技术研究的重要领域。具有电活性的小分子和纳米材料因它们独特的性质,已被应用到电化学DNA生物传感器中。本文介绍了电化学DNA生物传感器的基本概念和分类,综述了近年来电活性小分子和纳米材料在电化学DNA生物传感器中的应用进展,并对此领域的未来发展做了展望。     

Electrochemical Biosensors for Detection of Biological Warfare Agents

This review discusses current development in electrochemical biosensors for detection of biological warfare agents. This could include bacteria, viruses and toxins that are aerosoled deliberately in air, food or water to spread terrorism and cause disease or death to humans, animals or plants. The rapid and unequivocal detection and identification of biological warfare agents is a major challenge for any government including military, health and other government agents. Reliable, specific characterization and identification of the microorganism from sampling location, either air, water, soil or others is required. This review will survey different types of electrochemical biosensors has been developed based on the following: i) Immunosensors ii) PCR (DNA base Sensor) iii) Bacteria or whole cell sensor and iv) Enzyme sensor. This article gives an overview of electrochemical biosensor for detection of biological warfare agents. Electrochemical biosensors have the advantages of sensitivity, selectivity, to operate in turbid media, and amenable to miniaturization. Recent developments in immunofiltration, flow injection, and flow‐through electrochemical biosensors for bacteria, viruses, and toxin detection are reviewed. The current research and development in biosensors for biological warfare agents detection is of interest to the public as well as to the defense is also discussed.     

甘氨酸为络合剂是钯和葡萄糖氧化酶的电化学共沉积研究

甘氨酸和Ｐｄ（ＮＨ３）２Ｃｌ３组成镀液,用于钯和葡萄糖氧化酶（ＧＯＤ）的电化学共沉积以制备金属化酶电极、ＵＶ／Ｖ光谱实验表明甘氨酸能与Ｐｄ＾２＋离子发生络合作用,并使镀液在一定ｐＨ范围内具有较稳定的化学组成。伏安法实验证实甘氨酸的存在降低了Ｐｄ的沉积电位,有利于防止钯氢化合物的形成,讨论了钯和ＧＯＤ电化学共沉积的合适条件。     

Conducting Redoxpolymer-Based Reagentless Biosensors Using Modified PQQ-Dependent Glucose Dehydrogenase

Reagentless, oxygen-independent glucose biosensors based on an Os-complex-modified polypyrrole matrix and on soluble PQQ-dependent glucose dehydrogenase from Acinetobacter calcoaceticus are described.As the soluble form of glucose dehydrogenase from Acinetobacter calcoaceticus is a hydrophilic enzyme with a positive net charge, its entrapment into the positively charged hydrophobic polypyrrole film is much more complicated than that of the corresponding membrane enzyme or the negatively charged and very stable glucose oxidase. Possible ways for using soluble PQQ-dependent glucose dehydrogenase in combination with conducting polymer films are seen in the modulation of the enzyme properties by covalent binding of suitable compounds to the protein shell together with the adjustment of the properties of the conducting polymer film. This can be done by neutralising the net charge of the protein and/or optimising the electron-transfer pathway between enzyme and electrode surface by covalent binding of suitable redox relays to the protein surface.In addition, methods for increasing the hydrophilicity of the polymer film, such as the co-entrapment of high-molecular weight hydrophilic additives and copolymerisation of hydrophilic pyrrole derivatives are presented. It is demonstrated that the replacement of the parent monomer pyrrole by a suitable hydrophilic pyrrole derivative facilitates the entrapment of the modified soluble PQQ-dependent glucose dehydrogenase into the Os-complex-modified polymer and hence allows for the development of reagentless biosensors.     

电化学生物传感器在发酵领域中的应用

本文综述了近10年来电化学生物传感器在发酵领域中的研究及应用。首先介绍了电化学生物传感器的基本原理及分类,然后对发酵领域中应用和研究最为广泛的酶电极以及微生物电极传感器进行了分类描述,并重点介绍和归纳了葡萄糖、乳酸、酒精以及甘油生物传感器的研究现状,集中探讨了两类传感器的抗干扰性与选择性等特性。     

Application of Some Room Temperature Ionic Liquids in the Development of Biosensors at Carbon Film Electrodes

Two room temperature ionic liquids, 1‐butyl‐3‐methylimidazolium bistriflimide and 1‐butyl‐3‐methylimidazolium nitrate, were employed for enzyme immobilization in a new sol‐gel matrix and, for the first time, were successfully applied as electrolyte carriers in a biosensing system. The new sol‐gel matrix, based on 3‐aminopropyltrimethoxysilane and 1‐butyl‐3‐methylimidazolium bistriflimide mixtures, did not crack even after several weeks when kept dry, and exhibited similar analytical properties to aqueous sol‐gel based glucose biosensors. The linear range was up to 1.1 mM of glucose, sensitivity was 62 nA mM^?1 and the limit of detection was 28.8 μM. The optimum ionic liquid electrolyte carrier was found to be 1‐butyl‐3‐methylimidazolium nitrate, where the biosensor was made by electrodeposition of the redox mediator, poly(neutral red), and the enzyme was immobilized by cross‐linking with glutaraldehyde. The results showed that application of room temperature ionic liquids to biosensors is very promising and can be further exploited.     

Simulation of Electrochemical Process for Glucose Oxidase Immobilized Conducting Polymer Electrodes

Abstract

Computer simulation of electrochemical processes that govern the operation of conducting polymer modified electrodes (CPME) have been reported in this paper. Comparison of the behaviour of a biocatalyst (GOX) in free solution and in the immobilized phase in conducting polymer modified electrodes (CPME) has been provided The output has been obtained using the Runga Kutta numerical method solved by programming in FORTRAN 77. The results point out that the catalytic current generated by an immobilized enzyme in layer is larger as compared to that for the enzyme in solution, and that it varies with the thickness of the diffusion layer.     

Electrochemical Biosensors Based on Layer‐by‐Layer Assemblies

Layer‐by‐layer (LBL) assemblies, which have undergone great progress in the past decades, have been used widely in the construction of electrochemical biosensors. The LBL assemblies provide a strategy to rationally design the properties of immobilized films and enhance the performance of biosensors. The following review focuses on the application of LBL assembly technique on electrochemical enzyme biosensors, immunosensors and DNA sensors.     

Enhancing a Novel Robust Multicomposite Materials Platform for Glucose Biosensors

An effective, stable enzymatic glucose biosensor was fabricated on a glassy carbon electrode (GCE) surface using simple multicomposite materials (MCM): a solution of prepared poly(diallyldimethylammonium chloride)‐capped gold nanoparticles‐nickel ferrite particles‐carbon nanotubes‐chitosan (PDDA‐AuNPs‐NiFe₂O₄‐CNTs‐CHIT), electropolymerization of poly(o‐phenylenediamine) (PoPD) and immobilization of glucose oxidase (GOx). Biocompatibility and synergy of the MCM enhanced the immobilization and the reaction of GOx and as well as the electron transfer from an oxidation reaction of hydrogen peroxide in the system. The NiFe₂O₄ was synthesized by co‐precipitation and calcined at 700 °C. Characterization was carried out by field emission scanning electron microscopy (FE‐SEM), energy‐dispersive X‐ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) and X‐ray diffraction (XRD) which presented both tetrahedral and octahedral metal stretching with a cubic NiFe₂O₄ crystal phase. The GOx/PoPD/MCM/GCE yielded a 0.77 s^?1 charge transfer rate constant (K_s), a 2.28×10^?6 cm² s^?1 diffusion coefficient value (D), a 0.21 mm² electroactive surface area (A_e) and a 1.93×10^?8 mol cm^?2 surface concentration ( ) as determined by cyclic voltammetry. The modified electrode showed a durable operation time (n=97, more than 50 % I), repeatability (%RSD=0.38, n=10), reproducibility (%RSD=1.60, n=10), high sensitivity (853.07 μA mM^?1 cm^?2), selectivity without effects of electroactive species (aspirin, uric acid, caffeine, cholesterol, ascorbic acid and dopamine) and two linear ranges from 0.5 to 10 μM (R²=0.998) and 10 to 15,000 μM (R²=0.991) with a low detection limit (0.35 μM, S/N=3). Its Michaelis‐Menten constant (K_m) was calculated as 93.51 μM with 46.30 μA maximum current (I_max). This proposed simple method was successfully applied for glucose determination in human blood samples.     

Tuning of the electronic properties of self-assembling and highly sensitive chromic polyalkylthiophenes

The solvatochromic behaviour of different functional group-bearing and self-interacting polyalkylthiophenes with strong chromic responses in solution and self-assembling capacity in the solid state is investigated here. The menagerie of species deriving from the conformational freedom of the conjugated chains in solution has been examined in different solvent mixtures as their physico-chemical nature sensibly affects final material morphology in the solid (film) state. Memory of solution curling shape and of the degree of aggregation is in fact retained through casting or spin-coating procedures and permanently endures in the polymeric film. The efficiency of the final device based on the ICP (inherent conducting polymer) film may therefore be improved by simply acting on its morphology, which is directly determined by polymer dissolution conditions.     

基于纳米材料电化学生物传感器的研究进展

近年来,纳米材料在电化学生物传感器领域的研究已成为前沿性的内容.纳米材料具备优异的物理、化学、电催化等性能,加之其量子尺寸效应和表面效应,可将传感器的性能提高到一个新的水平.基于纳米材料的电化学生物传感器呈现出体积更小、速度更快、检测灵敏度更高和可靠性更好等优异性能.该文按照纳米结构的分类,综述了近几年基于以下纳米材料...