Ultrasensitive electrochemical detection of uric acid based on cobalt-embedded nitrogen-doped carbon

Abstract

Based on the electro-oxidation mode, electrochemical sensors provide an appealing evaluation tool for uric acid (UA) detection. However, improvements in the field of high-performance electrocatalysts remain necessary to enable wide-range and ultrasensitive detection of UA in this way. In recent years, the research and development of thermally treated metal (M) and nitrogen (N) co-doped carbon (M–N–C) catalysts, along with the usage of metal–organic framework materials as precursors, has substantially increased the performance of non-precious metal oxygen reduction catalysts, rendering them a potential species of the active substance. In this work, we synthesized cobalt metal-embedded nitrogen-doped carbon frameworks (Co–CN) through a host–guest synthetic strategy. An electrochemical sensing system was constructed for the accurate detection of UA molecules utilizing the excellent UA electrooxidation performance of Co–CN. The electro-oxidation reaction exhibits double electron/double proton transfer, and a response current signal can be obtained using differential pulse voltammetry (DPV), establishing a correlation between the measured UA concentration and the strength of the DPV current. The target UA concentration and DPV current density exhibited a dose-dependent relationship with a dynamic range of 2–120 μM and a limit of detection of 0.55 μM. During measurement, this sensing approach revealed good accuracy, high specificity, and adequate storage stability. It is worth noting that this detection system introduces a fresh approach for the development of sensitive, portable, and reasonably priced human metabolite analysis in wearable health monitoring devices.