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/RGO/PPy) nanocomposites 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   μM to 2.667   mM, a high sensitivity of 297.73   μA   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.