Enhancing Sensitivity of Novel Hg2+ Fluorescent Sensor via Plasmonic Enhancement of Silver Nanoparticles

•In this work, novel method to improve sensitivity of fluorescent sensor for Hg2+ detection by using plasmonic enhancement originated from surface plasmon resonance of silver nanoparticles has been demonstrated. The synthesized yellow silver nanoparticles (Y-AgNPs) were incorporated with the synthesized fluorescent sensor (sensor RBS) to form sensor RBS+Y-AgNPs. The sensitivity and selectivity studies of Hg2+ detection indicated that utilization of Y-AgNPs with sensor RBS could significantly improve the sensitivity of the sensor (lower the detection limit from 12.9ppb to 0.7ppb). Remarkably, sensor RBS+Y-AgNPs still exhibited high selectivity toward Hg2+ against interference ions including Ca2+, Cd2+, Co2+, Cu2+, Na+, Ni2+, Zn2+, Ba2+, K+, Cu2+, Pb2+, Fe2+, Li+, Mg2+and Hg2+. Furthermore, the developed method required use of only single excitation wavelength to achieve plasmonic enhancement of the fluorescent sensor.•We have shown that utilization of plasmonic enhancement of metal nanoparticle could significantly improve the sensitivity of the fluorescent sensor, which could pave the way for development of high sensitivity fluorescent sensor for an on-site detection of Hg2+.