Iodine-Mediated Etching of Triangular Gold Nanoplates for Colorimetric Sensing of Copper Ion and Aptasensing of Chloramphenicol.

A colorimetric method for fast, simple, and selective detection of Cu was developed using I-mediated etching of triangular gold nanoplates (AuNPLs). The method was based on our finding that Cu efficiently promoted this etching in the presence of SCN. The etching process was accompanied by a dramatic color change from blue to red, allowing for visual and spectroscopic detection of Cu with detection limits of 10 and 1 μM, respectively. When molecular recognition by a DNA aptamer was incorporated into this method, visual detection of chloramphenicol was also achieved with a detection limit of 5 μM.