Colorimetric Detection of Cadmium Ions Using DL-Mercaptosuccinic Acid-Modified Gold Nanoparticles

A colorimetric assay has been developed for detection of Cd2+ utilizing DL-mercaptosuccinic acidmodified gold nanoparticles (MSA-AuNPs). The method showed good selectivity for Cd2+ over other metal ions. As a result, the linear relationships (r > 0.9606) between concentration 0.07 mM and 0.20 mM for cadmium ion were obtained. The detection limit was as low as 0.07 mM by the naked eye. The effect of pH on the aggregation was optimized. The MSA-AuNPs probe could be used to detect Cd2+ in an aqueous solution based on the aggregation-induced color change of MSA-AuNPs.