| As a new type of probe, copper-gold composite nanomaterials can sensitively and selectively detect cysteine. In the presence of iodide ion, cysteine can enhance the absorption peak signal of copper-gold composite nanomaterials, so as to realize the quantitative detection of cysteine. The detection limit was 0.06 mmol/L and the linear range was 0 ～ 1 mmol/L. Compared with other amino acids, the sensor showed good selectivity for cysteine. The prepared copper gold composite nano materials can be directly used in the detection system without any treatment, which greatly simplifies the detection process. The sensor has the advantages of simplicity, rapidity and high selectivity, and can be used as a powerful tool for cysteine detection. |