An Enzyme Switch Employing Direct Electrochemical Communication between Horseradish Peroxidase and a Poly(aniline) Film

Bartlett, Philip N.; Birkin, Peter R.; Wang, Jinhai; Palmisano, Francesco; Benedetto, Giuseppe E. De

doi:10.1021/ac971088a

Cited by 149 publications

(86 citation statements)

References 32 publications

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“…These implantable biosensors must also be able to reject electrochemical interference by reducing agents present in the tissue, and a common strategy is the incorporation of a permselective membrane on the biosensor surface, such as electropolymerized PPD. 43,[75][76][77][78][79][80] This polymer is unusual 81 in that it displays very high permeability to the biosensor signal transduction molecule (H 2 O 2 , see…”

Section: Resultsmentioning

confidence: 99%

Contributions by a Novel Edge Effect to the Permselectivity of an Electrosynthesized Polymer for Microbiosensor Applications

et al. 2009

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Pt electrodes of different sizes (2 × 10 -5 -2 × 10 -2 cm 2 ) and geometries (disks and cylinders) were coated with the ultrathin non-conducting form of poly(o-phenylenediamine), PPD, using amperometric electrosynthesis. Analysis of the ascorbic acid (AA) and H 2 O 2 apparent permeabilities for these Pt/PPD sensors revealed that the PPD deposited near the electrode insulation (Teflon or glass edge) was not as effective as the bulk surface PPD for blocking AA access to the Pt substrate. This discovery impacts on the design of implantable biosensors where electrodeposited polymers, such as PPD, are commonly used as the permselective barrier to block electroactive interference by reducing agents present in the target medium. The undesirable "edge effect" was particularly marked for small disk electrodes which have a high edge density (ratio of PPDinsulation edge length to electrode area), but was essentially absent for cylinder electrodes with a length of >0.2 mm. Sample biosensors, with a configuration based on these findings (25 µm diameter Pt fiber cylinders) and designed for brain neurotransmitter L-glutamate, behaved well in vitro in terms of Glu sensitivity and AA blocking.The design of biosensors for implantation in functioning biological tissues is an important area of research with significant socioeconomic impact. 1-4 Depending on the target analyte, different signal transduction pathways have been exploited in the design of enzyme-based biosensors, including direct oxidation of reduced oxidases, 5-7 dehydrogenase chemistries, 8-10 redox mediators, 11-13 and spectrophotometric approaches. 14-16 However, "first generation" electrochemical biosensors, based on reactions 1-3, remain the most common design for many applications. 1,2,[17][18][19] The majority of these are oxidase-based devices designed to operate in amperometric mode, detecting H 2 O 2 generated by the reaction of the co-substrate (dioxygen) with the reduced form of the enzyme.First-generation biosensors in general, and especially those designed for tissue implantation, 20-24 must be capable of effective rejection of electroactive interference by endogenous reducing agents in the target medium because these devices are normally operated at a high applied overpotential for efficient H 2 O 2 * To whom correspondence should be addressed. E-mail: robert.oneill@ucd.ie.

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Section: Resultsmentioning

confidence: 99%

Contributions by a Novel Edge Effect to the Permselectivity of an Electrosynthesized Polymer for Microbiosensor Applications

et al. 2009

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“…A reliable, fast, accurate, and low level detection of H 2 O 2 has been the central task in various fields of analytical chemistry from environmental protection [23,24] to biosensors utilizing enzymes [25][26][27][28][29][30]. There are several disadvantages of the enzyme-modified electrodes, such as instability, high cost of enzymes and complicated immobilization procedure.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of 3D porous CeO2/reduced graphene oxide xerogel composite and low level detection of H2O2

Jha

Kumar

Raj

et al. 2014

Electrochimica Acta

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a b s t r a c tA novel synthetic approach has been designed to prepare CeO 2 /reduced graphene oxide (rGO) xerogel composite. The CeO 2 /rGO xerogel composite electrode displays much enhanced performance for the catalytic reduction of H 2 O 2 than the single component CeO 2 . The CeO 2 /rGO modified glassy carbon electrode displayed a wide linear range (60.7 nM-3.0 M), and low level of detection limit (30.40 nM) for H 2 O 2 and much higher sensitivity than that of CeO 2 nanoparticles modified electrode. The sensor fabricated by the xerogel composite was fast, stable, and reliable to the detection of hydrogen peroxide.

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“…1 Therefore, the determination of H2O2 is of great importance in both biological and industrial fields. [2][3][4][5] Electrochemical techniques have long been considered for the determination of H2O2, in view of its simplicity, low-cost and real-time detection properties. 6,7 Nevertheless, H2O2 is not an ideal species to detect with an electrochemical biosensor, because the electrode kinetics is very slow at most electrode surfaces.…”

mentioning

confidence: 99%

Incorporation of Horseradish Peroxidase in a Kieselguhr Membrane and the Application to a Mediator-free Hydrogen Peroxide Sensor

et al. 2001

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Hydrogen peroxide (H2O2) is a product of many enzymecatalyzed redox reactions. 1 Therefore, the determination of H2O2 is of great importance in both biological and industrial fields. [2][3][4][5] Electrochemical techniques have long been considered for the determination of H2O2, in view of its simplicity, low-cost and real-time detection properties. 6,7 Nevertheless, H2O2 is not an ideal species to detect with an electrochemical biosensor, because the electrode kinetics is very slow at most electrode surfaces. 8,9 It therefore requires high overpotentials to drive the reaction at an electrode, which often leads to low sensitivity and unacceptable interferences. 10 Therefore, peroxidase is often employed, to lower the activation energy for the reduction of H2O2 and to catalyze its electrochemical reduction at electrode surfaces. [11][12][13][14][15][16] Horseradish peroxidase (HRP) is a widely used peroxidase, due to its reasonable stability, commercial availability and effectiveness towards the reduction of H2O2. 17,18 Many good HRP-based H2O2 sensors have been constructed. [19][20][21][22][23] However, the redox center of HRP is electrically insulated by its thick protein shell, thus hindering its direct electrical communication with electrodes. Therefore, redox mediators usually have to be employed to shuttle electrons between the heme site of HRP and the electrodes.Meanwhile, although the direct electroreduction of H2O2 in the presence of HRP was observed at purposely pretreated carbon electrode surfaces, direct (i.e., mediator-free) electron transfer between the electrode and HRP is rather slow. Thus, no direct electrochemistry of HRP is observable in such cases. [24][25][26] Consequently, it is less efficient in the bioelectrocatalytic reduction of H2O2 and the biosensors exhibit lower sensitivity than those sensors that employ redox mediators.Recent studies have shown that the electron-transfer reactivity of proteins could be effectively enhanced after the proteins were incorporated in some membranes. 27 For example, Ferri et al. entrapped HRP within a tributylmethyl phosphonium chloride (TBMPC) polymer bound anionic exchange resin.The heterogeneous electron-transfer rate of HRP was greatly promoted and a pair of redox peaks of HRP was observed, corresponding to Fe(III)/Fe(II) conversion. 28 Hence, it combines the specificity of an enzymatic reaction with facile interfacial electron transfer, which shows great promise in biosensing applications. 29 Kieselguhr is a kind of inorganic material with a porous structure, which is promising as an immobilization matrix because of its good mechanical, thermal and chemical stability. 30 Moreover, kieselguhr is of special interest owing to its effectiveness in the retention of enzyme activity, 31 and its nice catalytic ability. 32,33 In this work, we incorporated HRP in the kieselguhr membrane. It was observed that HRP exhibits good direct electrochemical transfer reactions. Furthermore, a mediator-free H2O2 sensor is accordingly constructed. ExperimentalHRP (EC 1.11...

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An Enzyme Switch Employing Direct Electrochemical Communication between Horseradish Peroxidase and a Poly(aniline) Film

Cited by 149 publications

References 32 publications

Contributions by a Novel Edge Effect to the Permselectivity of an Electrosynthesized Polymer for Microbiosensor Applications

Contributions by a Novel Edge Effect to the Permselectivity of an Electrosynthesized Polymer for Microbiosensor Applications

Synthesis of 3D porous CeO2/reduced graphene oxide xerogel composite and low level detection of H2O2

Incorporation of Horseradish Peroxidase in a Kieselguhr Membrane and the Application to a Mediator-free Hydrogen Peroxide Sensor

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