Layer-by-layer inkjet printing of fabricating reduced graphene-polyoxometalate composite film for chemical sensors

Graphene oxide (GO) nanosheets and polyoxometalate such as H3PW12O40 (PTA) are prepared into a multilayer film via a layer-by-layer inkjet printing method. The GO/PTA composite thin film shows linear, uniform and regular layer-by-layer growth. Under UV-irradiation, a photoreduction reaction takes place in the film which converts GO to reduced GO (rGO) due to the photoreduction activity of polyoxometalate clusters. According to the cyclic voltammograms measurement, the rGO/PTA composite film displays good electrocatalytic activity for the oxidation of dopamine (DA). The oxidation peak current (I-pa) increases gradually with increasing the dopamine concentration, which may be used in electrochemical biosensors.