A low-cost high-entropy porous CrO/CrN/C biosensor for highly sensitive simultaneous detection of dopamine and uric acid

A low-cost high-entropy porous CrO/CrN/C biosensor was fast fabricated by mechanical milling strategy for simultaneous detection of dopamine (DA) and uric acid (UA). Biosensor carrier derived from the natural waste jasmine flowers (JF) could be coated by DA and then coordinated with Cr3+ with the aid of high-energy mechanochemistry, which fabricate porous Cr-JFC/DAC electrode with highly dispersed CrO/CrN sites. The formed large amount of high active sites significantly enhanced the biosensor’s response signal and resolution for the detection of DA and UA. Moreover, the high surface (950.1 m2/g), enriched interface and conductive carbon carrier efficiently improved the electrical signal transfer of biosensor. The Cr-JFC/DAC2 modified electrode was used for the simultaneous determination of DA and UA in the range of 0.05 ∼ 4 μM with a limit of detection (LOD) 10.65 and 17.54 nM (S/N = 3) respectively. The LOD were 1 ∼ 2 orders of magnitude less than reported state-of-the-art non-precious metal sensors, and even lower than those of most precious metal sensors. The analytical performance of the Cr-JFC/DAC2-modified electrodes has been evaluated using human serum samples with recoveries of 97.00%∼104.00%, good anti-interference and stability. Therefore, the Cr-JFC/DAC2/Nafion/GCE exhibited a great potential in the real application to simultaneously detect DA and UA.