A highly selective and non-reaction based chemosensor for the detection of Hg2+ ions using a luminescent iridium(III) complex.

Daniel Shiu-Hin Chan,Modi Wang,Wai-Chung Fu,Dik-Lung Ma,Chung-Hang Leung,Li-Juan Liu,Andrew C Marr

doi:10.1371/journal.pone.0060114

A highly selective and non-reaction based chemosensor for the detection of Hg2+ ions using a luminescent iridium(III) complex.

Daniel Shiu-Hin Chan, Modi Wang + Show 5 more

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https://doi.org/10.1371/journal.pone.0060114

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Journal: PloS one	Publication Date: Mar 22, 2013
Citations: 19	License type: CC BY 4.0

Affiliation: Hong Kong Baptist University, University of Macau

Abstract

We report herein a novel luminescent iridium(III) complex with two hydrophobic carbon chains as a non-reaction based chemosensor for the detection of Hg2+ ions in aqueous solution (<0.002% of organic solvent attributed to the probe solution). Upon the addition of Hg2+ ions, the emission intensity of the complex was significantly enhanced and this change could be monitored by the naked eye under UV irradiation. The iridium(III) complex shows high specificity for Hg2+ ions over eighteen other cations. The system is capable of detecting micromolar levels of Hg2+ ions, which is within the range of many chemical systems.

Highlights

Mercury is a highly toxic heavy metal ion that is harmful to both humans and the environment
The absorption band at 303 nm is assigned to an iridium-based spin allowed metal-to-ligand charge transfer (1MLCT) transition, while the low-energy absorption shoulder at approximately 450 nm is assigned to spin-forbidden triplet 3MLCT transitions according to the peak assignment of a similar iridium(III) complex [55]
Mercury ions may interact with the hydrophobic carbon chains of multiple complexes, inducing aggregation of the iridium(III) complexes into a micelle-like motif

Summary

Introduction

Mercury is a highly toxic heavy metal ion that is harmful to both humans and the environment. Traditional instrumental techniques for detection of Hg2+ ions include atomic absorption/emission spectrometry (AAS/AES) [4,5], inductively-coupled plasma mass spectrometry or atomic emission spectroscopy (ICP-MS/ICP-AES) [6,7,8] and X-ray fluorescence (XRF) [9,10,11]. Despite their widespread usage in industry and the laboratory, these methods are time-consuming and require extensive pre-treatment procedures, and involve the use of complex and expensive instrumentation. It is desirable to develop water-soluble luminescent probes for Hg2+ ions that can function effectively in aqueous solution

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