Conductive polymer modified electrodes

There has therefore been much interest in the mediation of redox reactions in solution by conducting polymer-modified electrodes. 

Yoon el al. [112] reported an all-solid-state sensor for blood analysis. The sensor consists of a set of ion-selective membranes for the measurement of H+, K+, Na+, Ca2+, and Cl. The metal electrodes were patterned on a ceramic substrate and covered with a layer of solvent-processible polyurethane (PU) membrane. However, the pH measurement was reported to suffer severe unstable drift due to the permeation of water vapor and carbon dioxide through the membrane to the membrane-electrode interface. For conducting polymer-modified electrodes, the adhesion of conducting polymer to the membrane has been improved by introducing an adhesion layer. For example, polypyrrole (PPy) to membrane adhesion is improved by using an adhesion layer, such as Nafion [60] or a composite of PPy and Nafion [117],... 

Scanning tunneling (STM) was invented a decade ago by Binnig and Rohrer [72], and was first applied to the solid-liquid interface by Sonnenfeld and Hansma in 1986 [73]. Since then, there have been numerous applications of STM to in situ electrochemical experiments [74-76]. Because the STM method is based on tunneling currents between the surface and an extremely small probe tip, the sample must be reasonably conductive. Hence, STM is particularly suited to investigations of redox and conducting polymer-modified electrodes [76,77],... 

Z. Li, H. Wang, S. Dong and E. Wang, Electrochemical investigation of DNA adsorbed on conducting polymer modified electrode, Anal. Sci., 13 (1997) 305-310. 

Different examples of hydrogenation of organic molecules with conducting polymer modified electrodes have been described rather recently in the literature. Two different kinds of modification have been considered for this application insertion of metallic particles, and functionalization of pyrrole with transition metal complexes leading, after electropolymerization, to active electrodes. 

M. Pyo, ControUed-release of biological molecules from conducting polymer-modified electrodes - the potential-dependent release of adenosine 5 -triphosphate from poly(pyrrole adenosine 5 -triphosphate) films, J. Electroanal. Chem., 368(1-2), 329-332 (1994). 

Ever since Feldberg s original model separating faradaic and capacitance current associated with a conducting polymer that behaves like a porous metal, " there have been various attempts to rationalize experimentally the nature of the current at a conducting polymer. Apart from impedance models, there has not been so much effort placed on modeling the system. Experimental efforts to examine processes at conducting-polymer-modified electrodes consisted of voltam-metry, " impedance, " and quartz crystal microbalance. However the... 

FIGURE 12.4 Bioelectronic detection of DNA hybridization based on electrochemical detection of ferrocene label at conducting polymer-modified electrodes. (Reprinted from Lei, C., Georghe, M., and Gtiiseppi-Elie, A., Proc. ACS PMSE Preprints 83, 552, 2000. With permission.)... 

Lupu, S., A. Mucci, L. Pigani, R. Seeber, and C. Zanardi. 2002. Polythiopbene derivative conducting polymer modified electrodes and microelectrodes for determination of ascorbic acid. Effect of possible interferents. Electroanalysis 14 519-525. 

The use of conducting polymers in sensor technologies involves employing the conducting polymers as an electrode modification in order to improve sensitivity, to impart selectivity, to suppress interference, and to provide a support matrix for sensor molecules [7,9,16,18,22,25,26,113-216]. All electrochemical transducer principles can also be realized with conducting-polymer-modified electrodes. The role of the conducting polymer may be active (for instance, when used as a catalytic layer, as a redox mediator, as a switch, or as a chemically modulated resistor, a so-called chemiiesistor ) or passive (for instance, when used as a matrix) [7,9,16,22,23,26,122,123,167,168,176,177]. 

Table 12, Some examples of application of intrinsically conducting polymer modified electrodes for the development of molecularly imprinted polymers...

Table 2.5 Examples of applicatirais of intrinsically conducting polymer modified electrodes in the frame of enzymatic biosensors...

II1-3 Dispersion of electrocatalysts into a conducting polymer modified electrode... 

The most common use for conductive polymer modified electrodes has been in the construction of sensor electrodes. These can be very selective and sensitive, and made to enhance the analysis of many different molecular entities. Thus, many different inorganic, organic, and biological species have been targeted (117). 

Singh, R. P. (2012). Prospects of organic conducting polymer modified electrodes enzymosen-sors. International Journal of Electrochemistry, 2012. 

Rahman A, Won M, Shim Y (2003) Characterization of an EDTA bonded conducting polymer modified electrode its application for the simultaneous determination of heavy metal ions. Anal Chem 75 2828-2834... 

Rahman MA, Park DS, Won MS, Park SM, Shim YB (2004) Selective electrochemical analysis of various metal ions at an EDTA bonded conducting polymer modified electrode. Electroanalysis 16 1366-1370... 

Conducting polymer-modified electrodes have potential usage in the fabrication of chemical detector for analytical applications [8]. As many of such research activities have focused extensively on the application of polypyrrole and its derivatives in the fabrication of biosensor especially glucose sensors [9], we have worked on the development of analytical probes using polythiophenes and polybithiophenes. An amperometric glucose sensors fabricated using enzyme/polybithiophene modified electrode has recently been reported [10]. 

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