Preferential Binding of Thioflavin T to AT-Rich DNA: White Light Emission Through Intramolecular Forster Resonance Energy Transfer.

作者：Mukherjee, Saptarshi; Pramanik, Srikrishna; Nandy, Atanu; Chakraborty, Subhajit; Pramanik, Ushasi; Nandi, Somen

来源：Journal of Physical Chemistry Letters, 2020.

DOI：10.1021/acs.jpclett.0c00237

Herein we report the effect of different nucleobase pair compositions on the association induced fluorescence enhancement property of Thioflavin T (ThT), upon binding with 20 base pair long double stranded deoxyribonucleic acid (dsDNA). Analysis of binding and decay constants along with the association (Kass) and dis-sociation (Kdiss) rate constants obtained from the fluctuation in the fluorescence intensity of ThT after binding with different DNA revealed selective affinity of ThT towards AT rich dsDNA. Molecular Docking also substantiates the experimental results. We also observed that addition of orange emitting Ethidium Bromide (EtBr) to cyan emitting ThT-DNA complexes leads to bright white light emission (WLE) through FRET. Additionally, the emission of white light is far more in the case of intra-DNA strands. Besides endorsing the binding insights of ThT to AT rich dsDNA, the present investigations open a new perspective for realizing promising WLE from two biomarkers without labelling the DNA.