A new rapid colorimetric detection method of Al3+ with high sensitivity and excellent selectivity based on a new mechanism of aggregation of smaller etched silver nanoparticles

Mechanism scheme of GSH-AgNPs with Cys for rapid colorimetric detection of Al3+. Cys may attack the surface of the AgNPs and replace GSH to some extent. The size of the AgNPs decreases because AgNPs could be etched by Cys. Slight aggregation may also happen because Cys is worse than GSH as a stabilizer. The smaller GSH-AgNPs etched by Cys aggregate to a great extent after being incubated with Al3+.