Boron‐Salphen Conjugate based Molecular Probe Exhibiting Fluorescence On‐Off‐On Response in Detection of Cu<sup>2+</sup> and ATP through Displacement Approach
Rimpi Bhandari, Ravisen Rai, Mohammed Kaleem, Rajesh Pratap, Nikita Shraogi, Satyakam Patnaik, Subrato Bhattacharya, Arvind Misra
Abstract
Abstract Synthesis and photophysical properties of a fluorescent probe HBD is described. Probe upon interaction with metal ions, anions and nucleoside pyrophosphates (NPPs) showed fluorescence quenching with Cu 2+ due to chelation enhanced quenching effect (CHEQ). Moreover, interaction of ensemble HBD .Cu 2+ with anions and NPPs showed fluorescence “turn‐ On” response with ATP selectively. “ On‐Off‐On ” responses observed with Cu 2+ and ATP is attributed to an interplay between ESIPT and TICT processes. Cyclic voltammogram of probe exhibited quasi‐reversible redox behaviour with three oxidation and two reduction potentials and the change in band gaps of probe suggested the interaction with Cu 2+ and ATP. The 2 : 1 and 1 : 1 binding stoichiometry for an interaction between probe and Cu 2+ (LOD, 62 nM) and ensemble, HBD .Cu 2+ with ATP (LOD, 0.4 μM) respectively are realised by Job's plot and HRMS data. Cell imaging studies carried out to detect Cu 2+ and ATP in HeLa cells. Also, the output emission observed with Cu 2+ and ATP is utilized to construct an implication (IMP) logic gate. Test paper strips showed naked‐eye visible color responses to detect Cu 2+ and ATP. In real water samples probe successfully detected copper (0.03 μM) between 5–6.5 ppb level (ICP‐MS method).