A colorimetric and near-infrared fluorescent probe with large Stokes shift for biothiol bioimaging

Abstract

Biothiols, essential sulfur-containing amino acids, play a critical role in various physiological processes in animals. Abnormal biothiol levels are closely associated with the onset and progression of numerous diseases, leading to increased research on their detection and quantification. While many fluorescent probes exist for biothiol tracking with a small Stokes shift, there is a scarcity of near-infrared (NIR) fluorescent probes with a large Stokes shift specifically for biothiols. This study introduces a new fluorescent probe, XB-F, based on the fluorinated NIR Rhodol. When biothiols are added, XB-F emits NIR light at 700 nm with a significant Stokes shift of 161 nm. The probe exhibits high sensitivity to biothiols, showing a 25-fold increase in fluorescence, along with excellent sensitivity and selectivity towards biothiols compared to other potential interferents in biological samples. Due to its low cytotoxicity, XB-F is suitable for detecting exogenous and endogenous biothiols in HepG-2 cells. Moreover, by utilizing its NIR emission with a large Stokes shift, XB-F is employed for monitoring biothiols in vivo. This innovative research opens avenues for further exploration into biothiol-related diseases, offering a valuable bioimaging tool for future studies.