Conducting Polymer

The conductance and electrostriction of bilayer lipid membranes (sBLM) supported on stainless steel and on conducting polymer polypyrrole (PPY) were studied. We showed that an increase in ammonia concentration resulted in an increase in d.c. current flow across the PPY layer adjacent to the metal surface and that covered by the lipid bilayer. The elasticity modulus in the direction perpendicular to the sBLM surface (E) and the electrical capacitance (C) were characterized by a complicated dependence on the application of an external d.c. voltage. In the case of sBLM formed on the PPY layer and that modified by avidin-urease, higher values of E were observed and in addition the latter system was characterized by a less expressed hysteresis of E and C than the metal supported sBLM. This is evidence that sBLM formed on PPY layers is smoother and more homogeneous than that formed on a metal support. We developed a urea minisensor based on sBLM supported on a PPY layer. Avidin-biotin tec...

Rapid advances in biosensors have recently been reported. This has been possible due to rapid growth in the development of new biomaterials such as conducting polymers, copolymers and sol gels etc and the reported improvements in sensing techniques. Biosensors are miniaturized devices employing biochemical molecular recognition as the basis for a selective analysis. The response generated as a result of biochemical reaction is detected by a transducer to give a signal (optical/electrical/thermal) that can be used with or without amplification for the estimation of the concentration of an analyte in a given test sample. Among the various biosensors, electrochemical sensors, especially amperometric biosensors presently hold a leading position.Due to specificity, portability, simplicity, high sensitivity, potential ability for real-time and on-site analysis coupled with the speed and low cost, biosensors have been projected to have applications in food analysis, environment control, clinical detection, drug and agriculture industries etc. Besides this, biosensors offer exciting opportunities for numerous decentralized clinical applications, ranging from emergency room screening, home self testing and alternative site testing, continuous and real-time in vivo monitoring. New generation of biosensors combining new bioreceptors with the ever-growing number of transducers is emerging. The present paper highlights some of the recent advances in the area of biosensors contributed by our laboratory.

Dielectric properties of some conducting polymers were investigated and their electrical properties are compared with each other. Temperature dependencies of their electrical properties are investigated throughout the work. Electrical behaviors of the synthesized systems constitute a good infrastructure for both understanding the intrinsic mechanisms and optimizing new synthesizes. It is found that, it can be possible to attain desired electrical properties by small synthesis modulations in thiophene based polymer materials.

Cell adhesion and proliferation in poly(3,4-ethylenedioxythiophene), an electroactive polythiophene derivative generated by anodic polymerization, has been investigated. Results show that epithelial cells Hep-2 present significant activity on the surface of poly(3,4-ethylenedioxythiophene) electrodeposited on stainless steel electrodes, no sign of cytotoxicity being detected for this conducting polymer. Indeed, seeded and cultured cells bound better to poly(3,4-ethylenedioxythiophene) than to uncoated stainless steel,

There are over 100 conducting polymers which have been synthesised by chemists with a wide range of specific electrical conductivities. Many of these polymers are suitable for elec tronic device fabrication. Semi-conducting and conducting polymers have potential for application in several areas. In this paper electronic and microwave properties are explored. Fabrication of elec tronic and microwave devices can be