Electrochemical dopamine sensor based on P-doped graphene: Highly active metal-free catalyst and metal catalyst support

•P-doped graphene (P-G) was synthesized by a thermal annealing method.•P-G was used for DA sensing as both metal-free catalyst and metal catalyst support.•P-G and Au/P-G exhibited a much improved catalytic activity for DA oxidation.•P-G and Au/P-G showed prominent DA sensing performances.•PG might be a promising electrode material for electrochemical sensing.

Heteroatom doping is an effective strategy to enhance the catalytic activity of graphene and its hybrid materials. Despite a growing interest of P-doped graphene (P-G) in energy storage/generation applications, P-G has rarely been investigated for electrochemical sensing. Herein, we reported the employment of P-G as both metal-free catalyst and metal catalyst support for electrochemical detection of dopamine (DA). As a metal-free catalyst, P-G exhibited prominent DA sensing performances due to the important role of P doping in improving the electrocatalytic activity of graphene toward DA oxidation. Furthermore, P-G could be an efficient supporting material for loading Au nanoparticles, and resulting Au/P-G hybrid showed a dramatically enhanced electrocatalytic activity and extraordinary sensing performances with a wide linear range of 0.1-180 μM and a low detection limit of 0.002 μM. All these results demonstrated that P-G might be a very promising electrode material for electrochemical sensor applications.

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