Urchin-like CoP/CuP heterostructured nanorods supported on a 3D porous copper foam for high-performance non-enzymatic electrochemical dopamine sensors.

In this study, we developed a high-performance non-enzymatic electrochemical sensor based on urchin-like CoP/CuP heterostructured nanorods supported on a three-dimensional porous copper foam, namely, CoP/CuP NRs/CF, for the detection of dopamine. Benefiting from the promising intrinsic catalytic activities of CoP and CuP, urchin-like microsphere structures, and a large electrochemically active surface area for exposing numerous accessible catalytic active sites, the proposed CoP/CuP NRs/CF shows extraordinary electrochemical response towards the electrocatalytic oxidation of dopamine. As a result, the CoP/CuP NRs/CF sensing electrode has a broad detection window (from 0.2 to 2000 μM), low detection limit (0.51 μM), high electrochemical sensitivity (0.0105 mA μM cm), excellent selectivity towards dopamine in the coexistence of some interfering species, and good stability for dopamine determination. More importantly, the CoP/CuP NRs/CF catalyst also exhibits excellent catalytic activity, sensitivity, and selectivity for dopamine detection under simulated human body conditions at a physiological pH of 7.25 (0.1 M PBS) at 36.6 °C.