Urchin-like CoP3/Cu3P heterostructured nanorods supported on a 3D porous copper foam for high-performance non-enzymatic electrochemical dopamine sensors†

Abstract

In this study, we developed a high-performance non-enzymatic electrochemical sensor based on urchin-like CoP₃/Cu₃P heterostructured nanorods supported on a three-dimensional porous copper foam, namely, CoP₃/Cu₃P NRs/CF, for the detection of dopamine. Benefiting from the promising intrinsic catalytic activities of CoP₃ and Cu₃P, urchin-like microsphere structures, and a large electrochemically active surface area for exposing numerous accessible catalytic active sites, the proposed CoP₃/Cu₃P NRs/CF shows extraordinary electrochemical response towards the electrocatalytic oxidation of dopamine. As a result, the CoP₃/Cu₃P 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⁻¹ cm⁻²), excellent selectivity towards dopamine in the coexistence of some interfering species, and good stability for dopamine determination. More importantly, the CoP₃/Cu₃P 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.