Highly selective and sensitive colorimetric detection of Ag(I) using N-1-(2-mercaptoethyl)adenine functionalized gold nanoparticles

A sensitive and selective colorimetric Ag+ detection method was developed by using N-1-(2-mercaptoethyl)adenine functionalized gold nanoparticles (MEA-AuNPs). The presence of Ag+ immediately induced aggregation of MEA-AuNPs, yielding a color change from red to blue. This Ag+-induced aggregation of MEA-AuNPs was monitored by bare eye and UV–vis spectroscopy with a detection limit of 3.3 nM. MEA-AuNPs showed excellent selectivity toward Ag+ compared with other metal ions through interaction between adenine and Ag+. The best detection of Ag+ was achieved at pH 6–9. Furthermore, MEA-AuNPs were applied to detect Ag+ in lake water with low interference.

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