Fast and selective detection of mercury ions in environmental water by paper-based fluorescent sensor using boronic acid functionalized MoS2 quantum dots

In this study, the B-MoS2 QDs, boronic acid functionalized MoS2 quantum dots, are synthesized by a simple aminoacylation reaction between MoS2 QDs and 3-aminobenzeneboronic acid (APBA). It not only exhibits excellent thermo-stability, photo-stability and good salt tolerance, but shows excellent fluorescence stability even under industrial wastewater with high concentration. These good characters can be used to construct a new fluorescence sensor for sensitive and selective detection of mercury ions (Hg2+). The fluorescence intensity of B-MoS2 QDs linearly decreases with the increase of Hg2+ concentration ranging from 0.005 to 41 mu mol L-1, and the limit of detection as low as 1.8 nmol L-1. Due to the mercury ion-promoted transmetalation reaction of aryl boronic acid, this proposed method exhibits fast response, ultra-sensitivity and high selectivity for analysis of Hg2+ in different environmental water, and which also uses to online monitoring of Hg2+. The B-MoS2 QDs-based test paper can be used to detect the trace amounts of Hg2+ under UV lamp by naked eyes, suggesting that the proposed method has potential application in on-site monitoring of environmental Hg2+.