Here we present a simple, low cost approach for the production of PEDOT nanofiber biosensors using simple techniques. Firstly, nanofibers of PEDOT were produced by the chemical vapor polymerization of EDOT on FeCl 3 containing electrospun PAN nanofiber mats. The nanofibers were characterized by SEM, FTIR, CV and conductivity studies, which indicated the formation of homogeneous, porous, electroactive PEDOT nanofibers. The fabrication of biosensors was achieved through the loading of various amounts of GOx on the nanofibers. To uncover their capability, the biosensors were operated under both hydrogen peroxide production and oxygen consumption conditions. For each biosensor current response versus glucose concentration calibration curves were plotted. The sensitivity, linear range, LOD, K m and I max values of the biosensors were determined and the stabilities of all the sensors were investigated. The biosensor operating at 0.6 V revealed a lower LOD with a wider linear range, higher stability, good sensitivity and selectivity. For example, the PEDOT-NFs/GOx-3 nanofiber biosensor showed good sensitivity (74.22 mA mM À1 cm À2 ) and LOD (2.9 mM) with a response time of 2-3 s without any interference effects. The PEDOT-NFs/GOx-2 biosensor operating at À0.6 V exhibited extreme sensitivity of 272.58 mA mM À1 cm À2. Our studies have shown that having good sensitivity, LOD and stability makes these interference-free, easy to construct sensors viable candidates for commercialization.

The present work demonstrates a novel, simple approach for fabrication of sensitive and selective glucose biosensors based on polypyrrole (PPy) nanofibers without using price-rising mediator or nanoparticles. The nanofibers were produced by chemical vapor polymerization of pyrrole on FeCl3 containing PAN nanofiber mats. Amperometric biosensors were constructed by entrapment of glucose oxidase on the nanofibers with the help of glutaraldehyde. The operational parameters such as pH, working potential, enzyme amount were optimized. For every biosensor sensitivity, linear range, limit of detection (LOD), and Michaelis-Menten constant values were determined and the stabilities of some of the sensors were tested. Our studies underlined the clear effect of enzyme content where the biosensors tend to show widened the linear detection range as the enzyme loadings increased +0.65V. PPy-NFs/GOx-1 biosensor showed good sensitivity (68.95 μA/mM.cm2) and LOD (7.8 μM) without any interference effect at +0.65V. On the other hand, when it was operated at −0.65V (oxygen consumption) the biosensor exhibited enhanced sensitivity of 116.42 μA/mM.cm2 with modest LOD and operational stability. Due to utilization of biocompatible, large surface area, nanoporous PPy nanofibers; an improved analytical performance was achieved with a very short response time, good stability and high selectivity, which make them feasible candidates for commercialization.

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