A photo-induced electron transfer based reversible fluorescent chemosensor for specific detection of mercury (II) ions and its applications in logic gate, keypad lock and real samples
Rajendran Ganesh Kumar, Subban Ravi, C. Immanuel David, Raju Nandhakumar
Abstract
A quantitative mercuric detection is very important in the environmental and biological systems. In this paper, we report a novel bis-rhodanine derived fluorescent chemosensor for recognition of Hg2+ ion in DMSO-H2O (1:1) medium. The ‘turn-on’ fluorescence response was exhibited specifically toward Hg2+ over other metal ions by receptor R2 at 410 nm, which could be ascribed to the restriction of photo-induced electron transfer (PET) process and chelation-enhanced fluorescence (CHEF) effect upon the complexation with mercury ions. The complexing stoichiometry of receptor R2 to Hg2+ was estimated to be 1:1 according to Job’s plot experiments. The limit of detection was calculated to be 7.33 × 10−7 M based on the concentration dependent emission changes with good association constant of 8.97 × 104 M−1. As a result, we express that receptor R2 is a promising candidate for Hg2+ recognition without any significant interference of other co-existing cations. The receptor R2 was successfully applied to molecular logic and keypad lock applications and real water samples to determine its potential applications.