Carbon-coated CoNiFeCuCr high-entropy alloy nanoparticles for robust electrochemical simultaneous detection of dopamine and uric acid.

Simultaneous electrochemical detection of dopamine (DA) and uric acid (UA) in complex biological media remains challenging due to overlapping oxidation responses, interference from coexisting species, and poor electrode durability. Herein, we present a carbon-coated high-entropy alloy, CoNiFeCuCr/C (HEA/C), as an electrochemical platform for selective DA and UA sensing, prepared through a one-step metal-organic chemical vapor deposition (MOCVD) route. The HEA/C electrode delivered well-resolved oxidation signals, rapid response, high sensitivity, strong anti-interference performance, and long-term stability. The sensor achieved detection limits of 0.50 μM for DA and 1.97 μM for UA, with repeatability RSDs of 2.22% and 0.57%, respectively. It maintained stable analytical performance over 65 days, with stability RSDs of 0.90% and 0.59% for DA and UA, respectively, and enabled reliable determination of both analytes in human urine, supporting its applicability to complex biological samples. Overall, these results demonstrate that HEA/C is a promising electrochemical sensing material for biomolecule detection and provides a useful strategy for developing advanced biosensing platforms.