A dibenzyl substituted poly (3,4-propylenedioxythiophene) was designed and synthesized, and exhibited a contrast of 89% at 632 nm with switching speeds of 400 ms and coloration efficiency of 575 cm 2 C 21 .Conjugated polymers 1 belong to an important class of polymers due to their widespread use in industrial applications like sensors, electrochromic materials, light emitting diodes (LEDs), actuators, and batteries etc. Electrochromics (ECs) are materials where the color exhibited is a function of applied potential. 2-4 Both inorganic and organic materials have been used as EC materials but there is still a lot of scope for further improvement in terms of switching speeds, stability, contrast and ease of synthesis and processing. Conducting or conjugated polymers have been found to be more promising as EC materials because of their better stability, faster switching speeds and easy processing compared to the inorganic EC materials. 2 EC materials where the color changes from a highly opaque colored state to highly transmissive bleached state are highly desirable as they are potential candidates for applications in display devices. In these systems, the change in percentage transmittance (D%T) between the two states is called the contrast and the higher the contrast, the better the material is for display applications. Conjugated polymers based on 3,4-alkylenedioxythiophene have attracted a lot of attention, both in academic as well as in industrial labs, as potential candidates for display applications because of their high contrast, low oxidation potential, better stability to air exposure at ambient and at elevated temperature conditions, and faster switching speeds. 5 Recently, Reynolds and coworkers have extensively studied the effect of ring size and also of ring substitution on the electrochromic properties of polymers based on 3,4-alkylenedioxythiophene. 5 They observed that the electrochromic contrast improves on increasing the ring size and also on increasing the interchain separation by the incorporation of a rigid/bulky side chain. 6 A tetradecyl substituted polyethylenedioxythiophene derivative was found to exhibit a D%T of 64%. However, the highest contrast (D%T of 78%) reported to date was observed in the case of a dimethyl substituted polypropylenedioxythiophene (PProDOT-Me 2 ). 7 Therefore, if one has to design a polymer with even better contrast than PProDOT-Me 2 one has to use more rigid/bulky substituents instead of methyl groups. Based on these facts, we designed and synthesized a dibenzyl propylenedioxythiophene (ProDOT-Bz 2 ) monomer (1). Incorporation of benzyl groups as the substituents, we think, will increase the interchain separation due to its rigid and bulky nature and hence the contrast. PProDot-Bz 2 exhibits an extremely high contrast of 89% at l max (632 nm) with coloration efficiencies of the order of 575 cm 2 C 21 ; in fact, these are the best reported values to date. In this communication, we report its synthesis, electrochemical and optical properties.The monomer 1 was synthe...

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Microtubule sensors for glucose, urea, and triglyceride were fabricated based on poly(styrene sulfonate)-polyaniline (PSS-PANI) composites synthesized within the pores of track-etched polycarbonate membranes. The synthesis of a sufficiently thick and conducting PSS-PANI film at pH 5 provided the advantage of immobilizing enzymes during polymerization. This resulted in the improvement of sensor response for urea and triglyceride by a factor of approximately 10(2) with a significant increase in the linear region of response compared to polyaniline-based sensors, where the enzymes were immobilized by physical adsorption after the polymerization. The sensors based on urea and triglyceride were found to have a higher linear range of response, better sensitivity, improved multiple use capability, and faster response time compared to the potentiometric and amperometric sensors based on polyaniline. A microtubule sensor array for glucose, urea, and triglyceride based on PSS-PANI was fabricated by immobilization of three different sets of enzymes on three closely spaced devices and its response was found to be free from cross-interference when a sample containing a mixture of the above analytes was analyzed in a single measurement.

A conductimetric reagentless immunosensor using the biospecific binding pair of goat antirabbit IgG and rabbit IgG has been designed and fabricated using poly (3,4-ethylenedioxythiophene) as the immobilization matrix-cumtransducer.

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