MXene/cobalt oxide nano-micro flower nanozymes for decentralized uric acid detection

Abstract

This research addresses the health implications of abnormal uric acid levels, which are linked to various conditions such as cardiovascular disease, acute kidney injury, kidney stones, gout, diabetes, and heart disease. Here, we developed a non-enzymatic, disposable sensor for point-of-care (POC) detection of uric acid, meeting the demand for low-cost and simple materials that offer excellent catalytic performance in real-world conditions. The sensor utilized a novel nano-microstructure of cobalt oxide/MXene, which was fabricated through an economical one-step electrodeposition method. The resulting nano-micro flowers (NMFs)-like structure, confirmed by Field Emission-Scanning Electron Microscopy (FE-SEM), significantly enhanced the reaction interface with uric acid. This morphology provided a high density of active sites, thereby improving catalytic activity and surface electrical potential (as investigated using simulated data from COMSOL Multiphysics software), and achieving an 8.6 times enhanced signal-to-noise ratio. The cobalt oxide NMFs sensor, fabricated in the presence of MXene, exhibited exceptional performance in challenging media, displaying wide linear range of detection between 50 and 1500 mu M. Additionally, the sensor maintained stability up to 28 days (RSD = 3.9 ). The sensor proved practical and selective in real applications, such as patient saliva and serum. The results showed a correlation coefficient of up to r = 0.96 with the Mindray BS-430 laboratory device. Also, clinical specificity of 100 for saliva and 92 for serum was achieved. Finally, this work represents a substantial advancement in nonenzymatic POC sensors, paving the way for the future development and application of disposable sensors for decentralized small molecule measurements.