Colorimetric sensor based on anti-aggregation of gold nanoparticles for silver ion detection in presence of APDC

In this study a selective, facile colorimetric probe was developed for detecting silver ion. This system works based on aggregation of gold nanoparticles (AuNPs) with ammonium pyrrolidine dithiocarbamate (APDC) and antiaggregation in presence of silver ion. APDC induces the aggregation of AuNPs leading to color change from red to blue, in presence of silver ion because of ability to form complex with APDC, aggregation of AuNPs inhibited, therefore color change occurs in reverse direction with increasing silver concentration (blue to red) [1]. Under optimized conditions this system exhibits high selectivity to Ag+ over other tested metal ions. This reported probe has advantages such as; wide linear range (1nM-700nM) and low detection limit (1.3*10 -8). The recovery analysis of river water and tap water as real samples confirmed that this colorimetric sensor could be successfully applied in environmental monitoring.