Ag⁰ decorated Cr₂S₃ NPs embedded on PVP matrix: A colorimetric probe for selective and rapid detection of sulphide...

Globally, the environmental pollution is one of the major issues causing toxicity towards human and aquatic life. We have developed a facile and innovative sensing approach for detection of sulphide ions (S^2-) present in the aqueous media using Ag⁰ decorated Cr₂S₃ NPs embedded on PVP matrix (Ag/Cr₂S₃-PVP). Based on the SPR phenomena, the detection of S^2- ions was established. The nanohybrid was characterized using various techniques such as UV-vis spectrophotometer, High-Resolution Transmission Electron Microscopy (HR-TEM), Thermal Gravimetric Analysis (TGA), X-ray diffraction analysis(XRD), Energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The yellowish colour of Ag/Cr₂S₃-PVP nanohybrid turned to brown colour in presence of S^2- ions. The selectivity and sensitivity of the prepared probe was studied against the other interfering metal ions. In addition, the effect of different concentration of S^2- ions in the nanohybrid solution was investigated and the Limit of detection (LOD) was found to be 6.6 nM. The good linearity was found over the range of 10 nM to 100 μM with R² value of 0.981. The paper strip based probe was developed for rapid onsite monitoring of S^2- ions. The proposed method is found to be cost-effective, rapid, and simple. We have validated the practical applicability of the prepared probe for determining the concentration of S^2- ions in real water samples.