Modulation in the binding sites for adaptable DNA interactive probe: Efficient at chromo-fluorogenic meticulous recognition of Al3+ and its live cell bioimaging

Abstract

Herein, a chromone based simple reversible fluorescent “turn-on” probe HMCP [6-(Hydroxymethyl)-N'-((6-methyl-4-oxo-4H-chromen-3-yl)methylene)picolinohydrazide] was successfully introduced to detect Al3+ over a group of other coexisting metal ions in methanol at pH 7.2. The “turn on” emission response along with the effective enhancement in fluorescence intensity upon addition of Al3+ can be attributed to the inhibition of photo-induced electron transfer (PET) and C=N isomerization as well as initiation of Chelation-enhanced-fluorescence (CHEF). The sensor HMCP binds Al3+ in 1:1 stoichiometry with a brilliant binding constant and good detection limit in the order of 103 M-1 and 10-7 M respectively. The binding mode of interaction of HMCP with Al3+ was supported by 1H-NMR titration, HRMS, Job’s plot analysis, theoretical calculations and also by molecular logic gate applications. DNA binding study was also executed to elucidate possible bioactivity and found that HMCP interacts with DNA more effectively over other analogues. Furthermore, the applicability in live cell imaging study indicated that HMCP is highly efficient to detect exogenous Al3+ in living cells. In addition, real sample analysis and dip-stick experiment provide a wide range of practical application of the probe conveniently.