Bimetallic copper-silver nanoclusters(DPA-Cu/Ag NCs) were prepared by one-pot method using penicillamine as reducing agent and stabilizer, and used as a sensor to detect silver ions in water samples. The Ag+ sensor has the advantages of low price, quick analysis speed and high selectivity. The structure and chemical composition of bimetallic copper-silver nanoclusters were characterized by transmission electron microscopy(TEM). The results showed that the DPA-Cu/Ag NCs exhibited a maximum emission at 555 nm with an excitation wavelength of 300 nm. It is a milky white solution under visible light, and the solution shows bright yellow fluorescence under UV light. When the preparation conditions of DPA-Cu/Ag NCs are optimized, it can be used as a probe to detect silver ions with high selectivity and sensitivity. The detection limit of silver ion is 0.3 μmol/L and the linear range is 0-500 μmol/L. The DPA-Cu/Ag NCs probe can also be applied to the detection of silver ion concentration in natural environmental water samples(lake water, bottled mineral water and laboratory tap water, etc.), and its detection performance is excellent with good percent of accuracy and reproducibility, indicating that the DPA-Cu/Ag NCs probe has extremely high application value in environmental monitoring. © 2022, Science Press. All right reserved.