This work describes a facile synthesis of polymer-capped silver nanoparticles at room temperature. Chitosan oligosaccharide lactate-capped silver nanoparticles (COL-AgNPs) show the surface plasma resonance (SPR) band at 400 nm. The color of the COL-AgNPs was observed to be brownish yellow. The synthesized COL-AgNPs are stable for 5 months. The COL-AgNPs were characterized by UV–vis, X-ray diffraction, high-resolution transmission electron microscopy (HR-TEM), mass, and Fourier transform infrared spectral techniques. The obtained COL-AgNPs are monodispersed, and the range of the particle diameter was calculated to be 16.37 ± 0.15 nm by HR-TEM. We have utilized the COL-AgNPs as a probe to sense iodide (I – ). The SPR band of COL-AgNPs was decreased after the addition of iodide, and the color of the solution changed to colorless. Based on the decreases in SPR band absorbance, the concentration of iodide was calculated. The detection limit was found to be 108.5 × 10 –9 M (S/N = 3). Other interferences (825- and 405-fold) did not interfere with the detection of 1.48 × 10 –6 M iodide. The sensing mechanism was also discussed. Finally, we have successfully applied our sensing system for the detection of iodide in tap water, river water, pond water, blood serum, urine, and food samples. Good recoveries are obtained with spiked iodide in the real samples. Importantly, we have developed a paper-based kit using wax-printed paper for the on-site monitoring of iodide. The developed paper-based kit absorbance was validated with the microplate reader. To the best of our knowledge, this is the first report that used six different real samples for the detection of iodide and development of the paper-based kit for on-site monitoring.

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Vanadium substituted polyoxometalate ionic liquids (POM‐ILs) with increase in alkyl chain lengths, C4MImPV3W9O40, C8MImPV3W9O40, and C16MImPV3W9O40 were prepared by simple ion exchange method. These materials were characterized by elemental analysis, FTIR, electron microscopy, and thermal analysis. The dye removal ability towards methylene blue and methyl orange was studied under neutral pH. The dye removal rate of C4MImPV3W9O40 and C8MImPV3W9O40 towards methylene blue was 95%. The dye removal rate of C16MImPV3W9O40 towards methyl orange was 92%.

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Vanadium substituted Keggin type polyoxometalate loaded N-doped carbon was prepared from polyoxometalate ionic liquid hybrid by carbonization process. The decomposition of organic part generates various functional groups leaving polyoxometalate part intact. The catalyst was characterized by elemental analysis, FTIR, MAS 13 C NMR, XPS and electron microscopy studies. The presence of carboxylic acids, aromatic and hetero-aromatic groups in the catalyst was confirmed by [a]

Detection of the amoxicillin drug using pyrogallol-derived carbon dots.

In this work, Keggin type phosphomolybdate inorganic‐organic hybrid material coordinated to with iron was synthesized by hydrothermal process followed by precipitation with organic cation. The prepared hybrid was fully characterized using conventional spectroscopic techniques. The adsorption efficiencies of the hybrid were evaluated for the removal of both anionic and cationic dyes from aqueous solutions. From the studies, it was concluded that hybrid has high adsorption as well as high selectivity for anionic dyes than cationic dyes. The results from the adsorption experiments revealed that the hybrid have specific methyl orange dye removal efficiency ≥96 % for 20 mgL−1 concentration. The reaction kinetics and adsorption isotherm also discussed.