Research Area

aza-BODIPY based NIR fluorescent and colorimetric probe for selective cysteine detection

Cysteine (Cys), homocysteine (Hcy) and glutathione (GSH) are essential biothiols for cellular growth, metabolism, and maintenance of biological system. Thus, the detection of biothiols is highly important for early diagnosis and evaluation of disease progression. In this article, a series of sulfonyl aza-BODIPY was synthesized, characterized, and examined by 1H-NMR, 13C-NMR, crystallization, photophysical properties and DFT calculation. Among these structures, a fluorescent probe (BDP-1), exhibited selective detection of Cys among various biothiols via nucleophilic aromatic substitution mechanism and typical size of Cys molecules. BDP-1 showed color change and near-infrared (NIR) fluorescent enhancement after reaction with Cys to generate BDP-OH, confirmed by HRMS. The red shift of absorption wavelength showed a similar tendency resulting in time-dependent density functional theory (TD-DFT). Furthermore, the calculated detection limit of BDP-1 toward Cys was 5.23 μM. This probe facilitates the colorimetric and fluorescent detection of Cys over other biothiols.