Carbon dots modified hydrange-shaped ZnCo(OH)F used as a flexible electrode for sensitive detection of dopamine and uric acid

Abstract

Dopamine (DA), widely recognized as the most prevalent catecholamine neurotransmitter in the brain, functions as a vital regulator of various physiological processes within the central nervous system. Meanwhile, uric acid (UA) serves as the terminal product of purine metabolism, and hyperuricemia emerges as a significant risk factor for gout, with a steep escalation in risk as blood uric acid levels surge. Consequently, monitoring the concentrations of DA and UA in biological fluids is crucial not only for the treatment of related disorders but also for enhancing disease prevention strategies. In this work, the blooming hydrangea shaped ZnCo(OH)F/carbon dots (CDs) composite was grown on carbon cloth (CC) substrate by a simple hydrothermal method, which was used as a flexible sensor for the detection of DA and UA. The unique open structure and morphologic adjustment strategy of ZnCo(OH)F/CDs/CC provided a large surface area and highly exposed active site. After screening the experimental variables that affect the sensor performance, the optimal ZnCo(OH)F/CDs/CC flexible electrode achieved individual and simultaneous detection for DA and UA in the concentration ranges of 1.0220.0 µM and 1.0500.0 µM, the detection limits (LOD) of DA and UA were 0.0129 and 0.044 μM, respectively (S/N=3). In addition, the sensor exhibited good repeatability, stability and selectivity, realizing the detection of DA and UA in human serum with recovery rate of 95.20 % 105.3 %. Also, the density functional theory (DFT) calculations were used to explore the interaction between electrode material and detected substrate. A simple hydrothermal method was utilized to grow the ZnCo(OH)F/CDs composite onto the CC substrate. The presence of F⁻ in ZnCo(OH)F can increase the charge mobility and improve the conductivity. ZnCo(OH)F/CDs/CC as flexible electrode material can determine DA and UA simultaneously in human serum with a satisfactory recovery rate. This flexible sensor has a broad application prospect in the manufacture of wearable devices.