Sensitive and selective colorimetric sensor detection of Sn (II): An aqueous, paper, and gel-based method by green biomimetic silver nanoparticles

Abstract

Tin contamination in waters due to mining and natural activities in high concentrations can threaten human health. This research presents the development of a sensitive and selective colorimetric sensor in aqueous, paper, and gel-based to detect Sn²⁺. The development of such sensors is promising, with attractive advantages such as intense color, fast naked-eye response, and simple continuous fabrication. The addition of Sn²⁺ ions will change the color of the medium because curcumin (Cur) interacts with Sn²⁺, causing a decrease in free Cur, silver nanoparticles (AgNPs) becoming less stable, and a change in particle size. Colorimetric changes in Sn²⁺ were achieved by visual inspection within 10 min for aqueous-based and 20 min for paper and gel-based. The good linear relationship (R² = 0.9999) between Sn²⁺ and Δ absorption with a detection limit of up to 66.99 µg/L. This method is relatively scalable in determining Sn²⁺ and shows good recovery between 80 and 105 %. This colorimetric sensor gives good sensitivity to Sn²⁺ metal ions which is expected to become the basic technology for developing in-situ sensors to monitor Sn²⁺ levels in tin industrial waste.