Facile Synthesis of Galactosamine‐Stabilized Gold Nanoparticles with Sensitive Cd²⁺ Sensing

Abstract

Cadmium is one of the most toxic and dangerous heavy‐metal elements to human health and environmental safety. Therefore, it is very useful to develop simple, rapid, and sensitive methods for the detection of Cd2+ ions in real samples. Here, we report the simple synthesis of galactosamine‐functionalized gold nanoparticles (Galn‐GNPs) at room temperature. The Galn‐GNPs can be used as a colorimetric probe for the detection of Cd2+ ions through localized surface plasmon resonance. A linear response to the concentration of Cd2+ ions was observed in the range 1 to 100 nM. The detection limit is as low as 3 nM, which is below the maximum recommended contamination level of the World Health Organization for cadmium in drinking water of 3 ppb (15 nM). The specific interactions of Cd2+ ions with Galn‐GNPs provided excellent selectivity for the detection of Cd2+ ions over 15 other metal ions (Pb2+, Mg2+, Zn2+, Ni2+, Cu2+, Co2+, Ca2+, Mn2+, Cr3+, Ba2+, Cr6+, Ag+, Fe3+, Al3+, and Hg2+). The selectivity of this system toward Cd2+ ions was remarkably fivefold higher than that for other metal ions. The aggregation‐based change in color from red to purple occurred in less than 20 s. This method is simple and fast and has also been successfully applied to the detection of Cd2+ ions in lake‐water samples.

Optical nanosensors based on noble metal nanoclusters for detecting food contaminants: A review

“…For instance, the WHO mandates Hg 2+ concentration in drinking water to be below 1 µg/L and Cd 2+ concentration under 15 nM. Nevertheless, some NMNC‐based optical nanosensors fall short of meeting practical requirements (Fu et al., 2015; Gao, Ma, Sun, et al., 2022; Li, Zhang, et al., 2022; Zhang et al., 2018). To summarize, substantial work remains to be done in applying NMNCs‐based optical nanosensors for hazardous ion detection, especially in enhancing their resistance to interference and sensitivity.…”