Adaptable DNA-Interactive Probe Proficient at Selective Turn-On Sensing for Al³⁺: Insight from the Crystal Structure, Photophysical Studies, and Molecular Logic Gate

Abstract

The synthesized Schiff base ligand 3-hydroxy- N ′-(2-hydroxy-3-methoxybenzylidene)-2-naphthohydrazide (H 2 NPV) is structurally characterized by single-crystal X-ray diffraction (XRD) and exhibits weak fluorescence in the excited state owing to the effect of excited-state-induced proton transfer (ESIPT). However, in the presence of Al 3+ , the ESIPT is blocked and chelation-enhanced fluorescence (CHEF) is induced because of complexation with the cations, resulting in turn-on emission for Al 3+ . The probe H 2 NPV selectively detects Al 3+ among the various metal ions, and the detection limit is found to be 1.70 μM. The composition and modes of complex coordination were determined by spectroscopic, theoretical studies and molecular logic gate applications. Finally, DNA binding studies were performed by spectroscopic and calorimetric methods to elucidate possible bioactivity of H 2 NPV.

New DNA-Interactive Manganese(II) Complex of Amidooxime: Crystal Structure, DFT Calculation, Biophysical and Molecular Docking Studies

“…Figure represents the Stern–Volmer plot for the fluorescence quenching of the Hoechst–DNA system by 1 . This observation suggests that 1 can dislocate Hoechst essentially from the adenine- and thymine-binding sites in the minor groove of DNA. ,, …”

“…This observation suggests that 1 can dislocate Hoechst essentially from the adenine-and thyminebinding sites in the minor groove of DNA. 29,30,44 Hydrodynamic Studies. Hydrodynamic study is an important method for ascertaining the mode of binding of small molecules with DNA.…”

“…Lamarckian genetic algorithm was used to carry out the docking calculations. Each run of the docking simulation was set to conclude after a maximum of 250,000 GA energy evaluations . The optimized docked model with lowest docking energy was chosen for further analysis of docking simulations.…”

“…The competitive binding efficiency between Hoechst 33258 and 1 with DNA was determined by fluorimetry in the range of 400−600 nm. 44 Aliquots of stock solution of 1 (upto 0−32 μM) were added to the equilibrated mixture of CT−DNA (20 μM) and Hoechst 33258 (1.91 μM) (termed as the Hoechst−DNA complex) at room temperature. The excitation wavelength was set as 350 nm.…”

“…Each run of the docking simulation was set to conclude after a maximum of 250,000 GA energy evaluations. 44 The optimized docked model with lowest docking energy was chosen for further analysis of docking simulations. The docked poses were analyzed and viewed in PyMOL software.…”