Electrochemical synthesis biological materials

Comparable to thiophene, pyrrole is a five-membered heterocycle, yet the ring nitrogen results in a molecule with distinctly different behavior and a far greater tendency to polymerize oxidatively. The first report of the synthesis of polypyrrole (PPy) 62 that alluded to its electrically conductive nature was published in 1968 [263]. This early material was obtained via electrochemical polymerization and was carried out in 0.1 N sulfuric acid to produce a black film. Since then, a number of improvements, which have resulted from in-depth solvent and electrolyte studies, have made the electrochemical synthesis of PPy the most widely employed method [264-266]. The properties of electrosynthesized PPy are quite sensitive to the electrochemical environment in which it is obtained. The use of various electrolytes yield materials with pronounced differences in conductivity, film morphology, and overall performance [267-270]. Furthermore, the water solubility of pyrrole allows aqueous electrochemistry [271], which is of prime importance for biological applications [272]. 

This chapter focuses on electrochemical biosensors that incorporated nanomaterials in their design, including the synthesis and characterization of these nanostruc-tured materials and their use with biological recognition elements. 

The importance of aqueous solid-liquid interfaces is not limited to biology but is also of major importance in earth science, colloid science, and several areas of surface chemistry. Other solid-liquid interfaces of practical importance, for example, include electrified metal-aqueous interfaces, as these are important for electrochemical reactivity across a number of fields involving corrosion, electrodeposition, and electrochemical energy storage. The extent to which lateral inhomogeneity on a nanoscale is important at these inorganic interfaces is increasing inline with the development of nanoscale textured surfaces and the synthesis of nanocomposite materials. 

Nanocomposites of conducting polymers exhibit improved physicochemical and biological properties as compared to their individual counterparts. The integration of secondary component within conducting polymer leads to dramatic increase in different properties that are useful from an application point of view. Size, shape and controlled distribution of the dispersed phase are the critical factors to control the desired properties of a nanocomposite. Different approaches such as in situ synthesis, one-pot synthesis, electrochemical polymerization and vapor-phase polymerization have been employed to synthesize the nanocomposites of conducting polymers with metal or metal oxide nanoparticles, carbon-based materials, ternary nanocomposites, etc. All of these methods have certain advantages and drawbacks. Functional nanocomposites synthesized by these methods display many... 

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