Fabrication of metal–organic single crystalline nanowires and reduced graphene oxide enhancement for an ultrasensitive electrochemical biosensor

A novel strategy is first presented here to design and construct a good selective and highly sensitive dopamine (DA) biosensor based on single-crystalline CuPc nanowires with a reduced graphene oxide–Nafion film (rGON/CuPcNWs). Metal–organic semiconductor single-crystalline CuPc nanowires with excellent electronic properties and large surface-to-volume ratios were prepared using a physical vapor transport technique and modified onto a glassy carbon electrode (GCE), and exhibited high electrocatalytic activity for DA detection by immobilizing it onto a GCE with a film of the rGON composite. The introduction of a rGO–Nafion film can significantly improve the electrochemical signal of the CuPcNWs. The relevant detection limit toward dopamine is 0.3 nM with a wide linear range from 0.001 μM to 200 μM. The results of the demonstrated biosensor could provide important enlightenment for the design of more sensitive electrochemical biosensors.