Heavy metal detection has received significant attention in recent years due to the increasing risk to human health and surrounding ecosystems. Here, the term heavy metal will encompass transition and post transition metals. Heavy metals that pose concern can span from biologically relevant transition metals like copper and zinc, to post transition metals like lead and chromium, to rare earth metals such as lanthanides and actinides. To date, there have been several reports of sensors that can quantitatively determine heavy metal concentrations in the environment, but those sensors can be rather limited in their application. Furthermore, successful multiplexed detection of heavy metals normally requires the use of complex instrumentation like inductively coupled plasma mass spectrometry. Other detection methods such as absorbance, electrochemistry, and fluorescence have been explored to create low-cost, easy-to-use, quantitative sensors but these typically detect single analytes with optimized reaction and coordination environments. This talk will focus on the development of one of the first host-guest mediated fluorescent arrays for multiplexed sensing of heavy metal ions. The use of fluorescence as the sensing mechanism allows for sensitive measurement while the host-guest supramolecular array permits multiplexed detection. The coordination environment of the host permits binding of several metal ions while the interactions of the guest in the cavity enables distinct fluorescent quantum yields, dependent on an individual metal ion.
(1) Liu, Y.; Mettry, M.; Gill, A. D.; Perez, L.; Zhong, W.; Hooley, R. J. Selective Heavy Element Sensing with a Simple Host–Guest Fluorescent Array. Anal. Chem. 2017, 89 (20), 11113–11121. https://doi.org/10.1021/acs.analchem.7b03377.