High selectivity improvement of chemosensors through hydrogen-induced emission (HIE) for detection of Hg2+ in vivo and in vitro

Abstract 2-(4-((4-Chloro-6-((3',6'-dihydroxy-3-oxospiro [isoindoline-1,9'-xanthen]-2-yl)amino)-1,3,5-triazin-2-yl)amino)benzoyl)-N-phenylhydrazine-1-carbothioamide (PCFH) is prepared for the detection of Hg2+ by hydrogen-induced emission (HIE). In the presence of blood serum, PCFH has a strong fluorescence response to Hg2+ in ethanol/H2O (90/10, v/v), while the fluorescence with other metal ions, including Cu2+, is much weaker. PCFH coordinates better with Hg2+ than Cu2+, which gives rise to specificity of detection. Through spectroscopic techniques and molecular dynamics simulations, the mechanism of HIE reveals that the interactions between polar bonds of PCFH and protein in blood serum via hydrogen bonding can efficiently enhance the specificity and sensitivity of detection. As the results of the interactions, the free rotation of two plenary structures of PCFH linked by C-C bonds is restricted, which leads to increased planarity, and the protein destroys the coordination between Cu2+ and PCFH. The development of cells under Hg2+ pollution is monitored, and the concentrations of Hg2+ in deformed and dead cells are 0.47 μM and 0.88 μM respectively. The HIE effects found here will promote new ideas in the design of new types of fluorescence probes for Hg2+ and other metal ions.