Turn-On Fluorescent Chemosensor for Hg2+ Based on Multivalent Rhodamine Ligands

Xuemei Wang,Willem Verboom,Jurriaan Huskens,Mudassir Iqbal

doi:10.3390/ijms131216822

Xuemei Wang, Willem Verboom + Show 2 more

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https://doi.org/10.3390/ijms131216822

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Abstract

Rhodamine-based fluorescent chemosensors 1 and 2 exhibit selective fluorescence enhancement to Fe3+ and Hg2+ over other metal ions at 580 nm in CH3CN/H2O (3/1, v/v) solution. Bis(rhodamine) chemosensor 1, under optimized conditions (CH3CN/HEPES buffer (0.02 M, pH = 7.0) (95/5, v/v)), shows a high selectivity and sensitivity to Hg2+, with a linear working range of 0–50 μM, a wide pH span of 4–10, and a detection limit of 0.4 μM Hg2+.

Highlights

Mercury is considered to be a highly dangerous element by the United States EnvironmentalProtection Agency due to its special properties, such as migration through cell membranes and bioaccumulation within living tissues [1,2]
Chemosensor 1 was synthesized starting from rhodamine B hydrazide (4) (1.3 g, 2.8 mmol), isophthaloyl dichloride (3) (0.29 g, 1.4 mmol) in THF (5 mL) and triethylamine (0.3 g, 3.0 mmol) in THF (70 mL)
For practical Hg2+ detection, the experimental conditions were optimized to CH3CN/HEPES buffer

Summary

Introduction

Mercury is considered to be a highly dangerous element by the United States Environmental. Protection Agency due to its special properties, such as migration through cell membranes and bioaccumulation within living tissues [1,2]. There is a high demand for the determination of the Hg2+ ion in environmental analysis. Rhodamine-based fluorescent chemosensors have received considerable attention for the detection of Hg2+ [3,4,5,6,7,8,9,10,11,12,13,14], Cu2+ [15,16,17], Pb2+ [18], Cr3+ [19], and Fe3+ [20], because their special structural properties provide an ideal mode to construct off-on fluorescent switch chemosensors.

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