Amperometric sensors modified

Reference electrodes Biomedical electrodes Apphcations to cations, anions Coated wire/hybrids ISFETs and related Biosensors Gas sensors Amperometric sensors Modified electrodes Gas sensors Biosensors... 

D.R. Shankaran and S.S. Narayanan, Amperometric sensor for thiols based on mechanically immobilised nickel hexacyanoferrate modified electrode. Bull. Electrochem. 17, 277-280 (2001). 

R.M. Ianniello and A.M. Yacynych, Immobilized enzyme chemically modified electrode as an amperometric sensor. Anal. Chem. 53, 2090-2095 (1981). 

Voltammetric/Amperometric Sensors Thick-film carbon-containing screen-printed electrodes modified with formazan [473] were used for zinc determination. 

A cleverly modified amperometric sensor measures glucose at a concentration of 2 fM in a 30 jlL volume containing just 36 000 molecules of glucose.14... 

In general, traditional electrode materials are substituted by electrode superstructures designed to facilitate a specific task. Thus, various modifiers have been attached to the electrode that lower the overall activation energy of the electron transfer for specific species, increase or decrease the mass transport, or selectively accumulate the analyte. These approaches are the key issues in the design of chemical selectivity of amperometric sensors. The long-term chemical and functional stability of the electrode, although important for chemical sensors as well, is typically focused on the use of modified electrodes in energy conversion devices. Examples of electroactive modifiers are shown in Table 7.2. 

Table 7.2 Examples of modifiers for amperometric sensors (adapted from Bard and Faulkner, 2001, pp. 584-585)...

Figure 9. Structure of the modified amperometric sensor. "Reproduced with permission from Ref. 13. Copyright 1984, The Chemical Society of Japan. "...

Figure 10. Response curve of the modified amperometric sensor to 2000 ppm H2 and dependence of short circuit current of the sensor on H2 concentration in air.

Figure 11. Sensing mechanism of the modified amperometric sensor.

E. Turkusic, V. Milicevic, H. Tahmiscija, M. Vehabovic, S. Basic and V. Amidzic, Amperometric sensor for L-ascorbic acid determination based on Mn02 bulk modified screen printed electrode, Fresenius J. Anal. Chem., 368 (2000) 466-470. 

P. Skladal and M. Mascini, Sensitive detection of pesticides using amperometric sensors based on cobalt phthalocyanine-modified composite electrodes and immobilized cholinesterases, Biosens. Bioelectron., 7 (1992) 335-343. 

Different other attractive way to modify the active electrode of amperometric sensors, besides deposition of polymers or electropolymerization, is formation of self-assembled structures, e.g., self-assembled monolayers (SAM) on solid supports 88 89 or bilayer lipid membranes (BLM) on various types of support.90 Both types of theses structures can either induce selectivity of sensor to particular analytes and... 

Hart J and Wring S 1994 Screen-printed voltammetric and amperometric sensors for decentralized testing Electroanalysis 6 617-24 Wang J 1991 Modified electrodes for electrochemical sensors Electroanalysis 3 255-9... 

Amperometric electrodes are a type of electrochemical sensor, as are potentiometric electrodes discussed in Chapter 13. In recent years there has been a great deal of interest in the developmenfoTv ious types of electrochemical sensors that exhibit increased selectivity or sensitivity. These enhanced measurement capabilities of amperometric sensors are achieved by chemical modification of the electrode surface to produce chemically modified electrodes (CMEs). 

Antiochia, R. Lavagnini, I. Magno, F. Electrocatalytic oxidation of dihydronicotinamide adenine dinucleotide with ferrocene carboxylic acid by diaphorase from Clostridium kluveri. Remarks on the kinetic approaches usually adopted. Ekctroanalysis 1999, 11, 129-133. Sanchez, P. D. Ordieres, A. J. M. Garcia, A. G. Blanco, P. T. Peroxidase ferrocene modified carbon paste electrode as an amperometric sensor for the hydrogen-peroxide assay. Ekctroanalysis 1991, 3, 281—285. 

A carbon paste electrode modified with Cu -doped clinoptilolite powder has been evaluated as an amperometric sensor for non-electroactive in flow injection analyses [48]. The conductivity of heulandite single crystals parallel to [100] has been studied under isothermal conditions as a function of the H2O content, small polar organic molecule concentration, and charge compensating cations. Results indicate that heulandite electrodes will be applicable for analytical purposes in aqueous solution [49]. 

L. Pigani, G. Loca, K. lonescu, V. Martina, A. Ulrici, F. Terzi, M. Vignali, C. Zanardi, and R. Seeber, Amperometric sensors based on poly(3,4-ethylenedioxythiophene)-modified electrodes Discrimination of white wines, Anal. Chim. Acta, 614, 213-222 (2008). 

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