Resazurin-based fluorescent probe for mercury ions and its applications in environment and biological systems

Mercury is considered to be one of the most typical and toxic elements of heavy metals in the environment, threatening human health even at very low level. For this reason, we developed a new fluorescence-enhanced probe RTQ based on resazurin dye, which realizes the selective detection of Hg²⁺ by using carbonothioate group as the recognition receptor. Probe RTQ can quantitatively assay Hg²⁺ ranging from 0-0.1 μM with a detection limit of 14 nM. Besides, the probe RTQ can specifically recognize Hg²⁺, resulting in a noticeable color change from mauve to dark blue. The relationship between the color change and Hg²⁺ content is analyzed using the RGB value analysis function of smartphones. RTQ can be fabricated into test strips as a portable tool for the detection of Hg²⁺. Finally, the successful applications of RTQ in environmental aqueous samples, cells and zebrafish demonstrate that it can provide a new promising tool for Hg²⁺ detection.