Electrodeposited honeycomb-like cobalt nanostructures on graphene oxide doped polypyrrole nanocomposite for high performance enzymeless glucose sensing

Honeycomb-like cobalt nanostructures modified graphene oxide doped polypyrrole (CoNSs/FtGO/PPy) nano- composites were successfully prepared via a simple two-step electrochemical synthesis route. Firstly graphene oxide (GO) doped PPy nanocompOsite was electrodeposited onto a pretreated glassy carbon electrode (GCE) to obtain GO/PPy nanocomposite; secondly honeycomb-like cobalt nanostructures were electrochemical reduced onto GO/PPy nanocomposite surface in a cobalt chloride solution at - 1.0 V. During the second reduction process, GO/PPy was reduced to a more conductive RGO/PPy nanocomposite simultaneously. The electrode modified with CoNSs/RGO/PPy nanocomposites exhibited outstanding electrocatalytic performance for enzymeless glucose sensing in alkaline media. Under optimum experimental conditions, the nonenzymatic glucose sensor displayed linear ranges from 0.5 mu M to 2.667 mM, a high sensitivity of 297.73 mu A mM(-1) cm(-2), a very low detection limit of 29 nM (at S/N = 3) and a superfast response time of 1 s. The developed glucose sensor displayed favorable selectivity against common interferents, excellent stability and high reproducibility, and it has great potential to successfully detect glucose concentration in real biological samples.