Facile fabrication of Ag2(bdc)@Ag nano-composites with strong green emission and their response to sulfide anion in aqueous medium

A novel composites constructed MOF(s) and Ag nanoclusters, Ag2(bdc)@Ag (H2bdc is 1, 4-benzenedicarboxylate) have been simply fabricated through solution strategy for the first time, and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy(XPS). The as-prepared composites were found to be an effective material for the selective fluorescence detection of microgram levels of S2− in aqueous solution based on fluorescence quenching effects. Under optimized experimental conditions, the probe exhibited a stable response for S2- over a concentration range from 0.2 μM to 30 μM and a detection limit of 0.21 μM. The feasibility of the proposed method was further demonstrated through the detection of S2- in real samples, with the satisfactory recoveries in the range of 97.8-101.9%. The possible sensing quenching mechanism for the detection of S2- could be attributed to the formation of Ag2S during the addition of S2- into the Ag2(bdc)@Ag dispersion system. The proposed method for the detection of S2- has potential application in the environmental pollutant analysis.