A colorimetric/luminescence sensor for detecting MeCN in water: Towards direct detection of dissolved organic contaminants

To address the need for a field-deployable in-situ technique for the accurate and reliable detection of organic contaminants in water, this work reports a new chemical sensing approach for the detection of aqueous MeCN. The approach relies on the reversible colorimetric/luminescent change in a transition metal complex. In this approach, a square planar platinum salt [Pt(tpy)Cl](PF6) (tpy = 2,2':6',2 ''-terpyridine) demonstrated a reversible color change from yellow to red as well as a red shift in emission intensity upon exposure to aqueous MeCN. This observed spectroscopic change was induced by the incorporation of MeCN molecules withing the crystal lattice of the platinum salt, that resulted in an enhancement in the intermolecular Pt center dot center dot center dot Pt interactions, which correlatively altered the electronic structure. The spectroscopic response was highly selective and quantitative for aqueous MeCN. This work illustrates a new technique for the rapid, selective, sensitive detection of aqueous MeCN, while also providing a general strategy for the detection of other small molecule contaminants.

Automated summary

This study presents a new chemical sensing approach for the accurate detection of aqueous MeCN, based on reversible colorimetric/luminescent changes in a transition metal complex. By observing the reversible color change from yellow to red and the red shift in emission intensity of the platinum salt, the spectroscopic response showed high selectivity and quantitativeness for aqueous MeCN. This work not only provides a new technique for rapid and sensitive detection of aqueous MeCN, but also offers a general strategy for detecting other small molecule contaminants.