Fluorescence and FRET based mercury (II) sensor

TL;DR

This paper introduces a simple FRET-based fluorescence sensor for detecting mercury (II) ions in water, showing linear response and a detection limit of 9.13 ppb, suitable for real water samples.

Contribution

It presents a novel, easy-to-use FRET sensor system for Hg2+ detection that operates effectively in aqueous environments and has been validated with real lake water samples.

Findings

Linear decrease in fluorescence intensity with Hg2+ concentration

Detection limit of 9.13 ppb for Hg2+ ions

Successful application in real lake water samples

Abstract

A mercury (II) sensor has been proposed based on Fluorescence Resonance Energy Transfer (FRET) between N,N'-dioctadecyl thiacyanine perchlorate (NK) and Octadecyl rhodamine B chloride (RhB). Out of these two molecules NK is sensitive to Hg2+ ions due to presence of sulfur atom in it. Accordingly, presence of Hg2+ ions affects the NK fluorescence as well as FRET from NK to RhB. Our results showed that NK fluorescence intensity and FRET efficiency linearly decreases with increase in Hg2+ ion concentration. With proper optimization present system under investigations can be used to sense Hg2+ ions in aqueous solution with detection limit of 9.13 ppb. Advantage of this present system is that it is very simple compared to the other FRET based system and also it works under aqueous environment. This method has also been tested using real lake water and satisfactory results were obtained.