High-entropy Ag,Pt-based catalyst toward exceptionally high-performance and stable electrochemical detection of nitrite†

The undisclosed and exceptional electrochemical nitrite sensing performance of a high-entropy Ag,Pt-based catalyst (FeAlCoAgPt) prepared via a solvothermal synthesis method is reported. The morphology, structure, and elemental composition of the prepared FeAlCoAgPt catalysts were characterized using X-ray diffractometry (XRD), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The prepared FeAlCoAgPt catalysts were utilized to modify glassy carbon electrodes (GCE), forming the modified electrode FeAlCoAgPt/GCE, which was employed for the electrochemical detection of nitrite. Electrochemical studies showed that FeAlCoAgPt/GCE exhibited a wide linear nitrite determination range of 1.0 μM to 10.0 mM, a low limit of detection (LOD) and quantification (LOQ) of 0.92 μM (S/N = 3) and 3.07 μM (S/N = 10) respectively, a high sensitivity of 42.59 μA mM⁻¹ cm⁻², and a quick nitrite response at 0.85 V (response time of 1.2 s), which compared favorably with recent reports in the literature. FeAlCoAgPt/GCE also exhibited favorable anti-interference ability, satisfactory repeatability and extraordinary stability and reusability, and has good feasibility for real sample analysis of nitrite in lake water and milk, with recovery rates ranging from 96.33 to 104.76% and RSD values of less than 4%. As an ideal catalyst with high and stable detection performance, the high-entropy Ag,Pt-based catalyst has great potential to be integrated into next-generation electrochemical sensing devices.