Coumarin-based fluorescent sensors for zinc(II) and hypochlorite

Abstract

Two new fluorescent chemosensors have been designed and synthesised through functionalisation of a common 7-aminocoumarin precursor. One sensor features a di(2-picoyl)amine metal ion-binding moiety that allows for selective detection of Zn²⁺ ions over other common cations in aqueous solution, with the sensor exhibiting a 5.4-fold increase in fluorescence upon Zn²⁺ binding (limit of detection = 26 nM). The second sensor incorporates an aminophenyl group designed to react with highly reactive oxygen species (hROS). This sensor reacts with ClO⁻  in preference to other ROS, exhibiting a 27-fold increase in fluorescence upon the addition of 150 equivalents of ClO⁻  (limit of detection = 2 μM).

Keywords:

• chemosensor
• coumarin
• zinc
• reactive oxygen species
• hypochlorite

Supplemental data

Experimental procedures for compounds 3, 7, 8, 9, UV-vis absorbance spectra for sensors 1 and 2, Job plot analysis for binding of Zn²⁺ by sensor 1, and fluorescence of sensor 1 upon standard addition of Zn²⁺ ions to a spiked environmental sample. Supplemental data for this article can be accessed here: http://dx.doi.org/10.1080/10610278.2015.1077958.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

^1. This sample was analysed for ICP-MS and the total concentration Zn in solution was below 5 nM.

Additional information

Funding

The authors acknowledge the support of the School of Chemistry and Monash Institute of Pharmaceutical Sciences, Monash University. Financial support from the Australian Research Council is gratefully acknowledged [grant numbers DP150100383 and FT130100838].