A sensitive turn‐off–on fluorometric sensor based on S,N co‐doped carbon dots for environmental analysis of Hg(II) ion

Authors:
Publisher website
Google Scholar
Abstract
A simple and sensitive fluorescence turn‐off‐on sensor was established by means of S,N co‐doped carbon dots (S,N‐CDs) and Ag nanoparticles (AgNPs) for the determination of Hg2+. For this purpose, blue emissive S,N‐CDs were hydrothermally synthesized and characterized using transmission electron microscopy, Fourier transform infrared spectroscopy, and energy dispersive X‐ray spectroscopy. We observed that the fluorescence intensity of the as‐prepared S,N‐CDs was impressively quenched by AgNPs. The quenching mechanism was studied and attributed to nanosurface energy transfer and the inner filter effect between S,N‐CDs and AgNPs. Furthermore, by adding Hg2+, the fluorescence intensity of S,N‐CDs/AgNPs was restored as a result of aggregation of AgNPs in the presence of Hg2+. Based on these facts, S,N‐CDs and AgNPs were exploited to design a sensitive turn‐off–on sensor for analysis of Hg2+. The recovered fluorescence signal was proportional to the concentration of Hg2+ in the range 1.5–2000 nM with a detection limit of 0.51 nM. The established sensor was used with satisfactory results for measurement of Hg2+ in environmental water samples.

This publication has 47 references indexed in Scilit: