Graphene oxide doped poly(3,4-ethylenedioxythiophene) modified with copper nanoparticles for high performance nonenzymatic sensing of glucose

Abstract

A highly stable and sensitive nonenzymatic glucose sensor was successfully constructed through a facile electrodeposition method. Graphene oxide (GO) doped poly(3,4-ethylenedioxythiophene) (PEDOT) was first electrodeposited onto a glass carbon electrode using cyclic voltammetry and copper nanoparticles were then electrodeposited onto the rough surface of the PEDOT/GO nanocomposite through electrochemical reduction in a solution containing copper cations. The modified electrode was used for reliable nonenzymatic electrochemical detection of glucose, and under optimized conditions, it exhibited a high sensitivity of up to 909.1 μA mM⁻¹ cm⁻² and a very fast response time of less than 1 s, with a wide linear range of 0.1 μM to 1.3 mM and a low detection limit of 47 nM. This nonenzymatic glucose sensor was, furthermore, highly stable and unresponsive to potentially interfering substances, and it could be used for the assay of glucose in real human serum samples. These enhanced sensing performances were ascribed to the close contact of copper nanoparticles onto the rough surface of the PEDOT/GO conducting polymer nanocomposite, which has good conductivity and very high surface area that can act as an excellent substrate for the growth and support of copper nanoparticles. All these results indicate that this electrochemical sensor is highly promising for nonenzymatic glucose detection.