ag-based nanoparticle as a colorimetric sensor array for identification and determination of mixture of halides and sulfide

Abstract: inorganic anions such as halide ions and sulfide in excessive or insufficient dosage could lead to environmental risk and human health problems. given the pressing demand for inorganic anions detection, considerable progress in analytical methodology development has been made in the past decade. the plasmonic metal sensors have recently received much attention in colorimetric assaying of various chemical species because of size-dependent visual changes, simplicity, selectivity, and high sensitivity in multidisciplinary research areas. colorimetric sensor arrays comprised of metallic nanoparticles combining with chemometric techniques are suitable analytical tools for the detection and classification of different compounds in the mixture [1, 2]. in this study, a very simple and efficient color sensor array based on the cumulative behavior of silver nanoparticles, which is a combination of two different nanoparticles including ag nps and ag-chitosan nps, to identify and classify inorganic anions including br-, i- and s2- will be developed. the characterization study of silver embedded chitosan were studied by fourier transform infrared spectroscopy (ftir), x-ray diffraction spectroscopy (xrd) and scanning electron microscope (sem). the interaction of nanoparticles and anions will be measured by a spectrophotometer and the amount of change in their observable spectra. the obtained results were shown that the collective behavior of nanoparticles was changed by introducing anions into array, resulting in providing different colorimetric responses and fingerprint-like patterns for each anion. the principal component analysis (pca) and hierarchical clustering analysis (hca) were used to analyze the obtained patterns and generate a clustering map for classifying br-, i- and s2-. in addition, the quantitative detection performance of the sensor array on simultaneous determination of studied anions in mixtures was examined.