Nickel nanoparticle-chitosan-reduced graphene oxide-modified screen-printed electrodes for enzyme-free glucose sensing in portable microfluidic devices.

A facile one-step strategy is reported to synthesize nanocomposites of chitosan-reduced graphene oxide-nickel nanoparticles (CS-RGO-NiNPs) onto a screen-printed electrode (SPE). The synthesis is initiated by electrostatic and hydrophobic interactions and formation of self-assembled nanocomposite precursors of negatively charged graphene oxide (GO) and positively charged CS and nickel cations (Ni(2+)). The intrinsic mechanism of co-depositions from the nanocomposite precursor solution under cathodic potentials is based on simultaneous depositions of CS at high localized pH and in situ reduced hydrophobic RGO from GO as well as cathodically reduced metal precursors into nanoparticles.