A Fluorescent Chemodosimeter for Hg2+Based on a Spirolactam Ring-Opening Strategy and its Application Towards Mercury Determination in Aqueous and Cellular Media

A novel fluorescent chemosensor rhodamine B phenyl hydrazide (RBPH) for Hg²⁺ was designed and synthesized. This probe is highly sensitive, selective, and irreversible for Hg²⁺ and exhibits fluorescent response at 580 nm. RBPH also displayed detectable color change from colorless to pink upon treatment with Hg²⁺. This property has been utilized as naked eye detection for Hg²⁺ in various industrial samples. Fluorescence microscopic experiments demonstrated that this chemosensor is cell permeable and can be used for fluorescence imaging of Hg²⁺ in cellular media. This probe can detect Hg²⁺ with good linear relationships from 1 to 100 nM with r?=?0.99983 and the limit of detection were found to be 0.019 nM with?±?0.91 % RSD at 10 nM concentrations.