Highly selective fluorogenic probe served as a fluorescent marker in the biosorption capacity evaluation of gram-negative bacteria for Hg2+

A novel fluorescent compound Tetra((4-bis(2-hydroxyethyl)amino)methyl phenyl)ethene (3) was synthesized and employed as a fluorogenic probe for detecting Hg2+. This probe exhibits low fluorescence in aqueous environment, which can be enhanced in the presence of Hg2+ due to the complexation between 3 and Hg2+. Furthermore, the fluorescence intensity of 3 can be further enhanced upon addition of lipopolysaccharide (LPS), because the binding between 3-Hg2+ and LPS activate the aggregation-induced emission (AIE) property of compound 3. Therefore, this fluorescence probe is employed as a fluorescent marker to monitor the interaction between Hg2+ and gram-negative bacteria. The biosorption capacity for Hg2+ of gram-negative bacteria is evaluated conveniently by the fluorescence intensity change of compound 3.