Sensitive and Selective Electrochemical Determination of L-Cysteine Based on Cerium Oxide Nanofibers Modified Screen Printed Carbon Electrode

A novel L-cysteine (CysH) electrochemical sensor based on CeO2 nanofibers (NFs) modified screen printed carbon electrodes (SPCEs) was developed. The morphology and the structure of the as-prepared CeO2 NFs were first characterized using scanning electron microscopy (SEM) and X-ray diffraction pattern (XRD), respectively. The electrochemical and electrocatalytic performances of the CeO2 NFs modified SPCEs were then evaluated using cyclic voltammetry and amperometry. Experimental results showed that the CeO2 NFs modified SPCEs possess excellent electrocatalytic activity toward the detection of CysH. Specifically, the developed electrochemical sensor demonstrated a high sensitivity of 120AmM(-1)cm(-2), a low detection limit of 20nM (signal to noise ratio of 3) and a wide linear range up to 200M for the determination of CysH, which are among the best values reported in literature. In addition, good selectivity and outstanding intra- and inter-electrode reproducibility have also been observed. Furthermore, the developed CysH sensor was applied to detect CysH spiked into human serum samples with remarkable accuracy. All these features indicate that CeO2 NFs hold great promise in the development of high performance electrochemical sensor for CysH.