Bis-triazolylchalcogenium-Functionalized Benzothiadiazole Derivatives as Light-up Sensors for DNA and BSA
Roberta Krüger, Allya Larroza, Mariana G. Fronza, Isadora Tisoco, Lucielli Savegnago, Joel S. Reis, Davi F. Back, Bernardo A. Iglesias, Diego Alves
Abstract
A range of bis-triazolylchalcogenium-BTD 3 was synthesized by a copper-catalyzed azide–alkyne cycloaddition of azido arylchalcogenides 1 and 4,7-diethynylbenzo[c][1,2,5]thiadiazole 2. Eight new compounds were obtained in moderate to good yields using 1 mol % of copper(II) acetate monohydrate under mild reaction conditions. In addition, the synthesized bis-triazolylchalcogenium-BTD 3a–3h were investigated regarding their photophysical, electrochemical, and biomolecule binding properties in solution. In general, compounds presented strong absorption bands at the 250–450 nm region and cyan to green emission properties. The redox process attributed to the chalcogen atom was observed by electrochemical analysis (CV techniques). In addition, spectroscopic studies by UV–vis, steady-state emission fluorescence, and molecular docking calculations evidenced the ability of each derivative to establish interactions with calf-thymus DNA (CT-DNA) and bovine serum albumin (BSA). The behavior presented for this new class of compounds makes them a promising tool as optical sensors for biomolecules.