Self-assembly of 1,3-alternate calix[4]arene carboxyl acids-modified silver nanoparticles for colorimetric Cu2+ sensing

In this study, a novel colorimetric sensor based on 1,3-alternate calix[4]arene-modified silver nanoparticles (Ag NPs) was synthesized. The functionalized Ag NPs were characterized by Transmission Electron Microscopy (TEM) and Infrared Spectroscopy (IR). It was observed that the Ag NPs synthesized had a high selectivity for Cu2+ ions with the detection limit of 2.5 × 10−6M. Based on the findings in this research, the 1,3-alternate calix[4]arene-modified Ag NPs was found to be useful for colorimetric detection of Cu2+ in solution. Moreover, the Ag NPs continued to grow and larger three-dimensional aggregates were formed with increasing concentration of Cu2+.