Improving sensitivity of a new Hg2+-Selective fluorescent sensor by silver nanoparticles via plasmonic enhancement

A new Hg2+-selective fluorescent sensor which consisted of tripodal ligand connected to three 7-nitrobenzo-2-oxa-1,3-diazolyl (NBD) moieties (TNBD) was successfully synthesized. This sensor exhibited high Hg2+-selectivity over other interfering ions with the detection limit of 12.5 ppb. Furthermore, plasmonic enhancement of the synthesized purple silver nanoparticles (P-AgNPs) was utilized to enhance sensitivity of TNBD. Remarkably, the sensor containing P-AgNPs (TNBD P-AgNPs) preserved high selectivity toward Hg2+ with better detection limit (3.8 ppb) compared to the bare sensor. Moreover, Hg2+ detection in real samples (drinking water) by TNBD + P-AgNPs was accomplished which indicated that the sensor could operate in the presence of aqueousconsisted matrix. Therefore, the developed sensor was practical and could be applied for Hg2+-detection in biological samples.

Automated summary

A new Hg2+-selective fluorescent sensor with high selectivity and low detection limit was successfully synthesized, demonstrating improved sensitivity when combined with purple silver nanoparticles. The sensor showed excellent performance in real samples and can be applied for Hg2+ detection in aqueous matrices.