Colorimetric and NIR Fluorescence Probe with Multiple Binding Sites for Distinguishing Detection of Cys/Hcy and GSH in Vivo

Although some progress has been made in distinguishing the detection of biothiols, NIR biothiol fluorescent probes for simultaneously distinguishing detection of Cys, Hcy, and GSH in vivo have not been reported. The design of these probes involves the introduction of NIR fluorophores and multiple binding sites; thus, the integrated design of probes remains a challenge. Although Cys, Hcy, and GSH have common functional groups, a sulfydryl group and an amino group, due to their differences in spatial structure, they may react with multiple binding site probes to produce different reaction products in different bonding mechanisms, resulting in different colors and fluorescent signal changes of the system. Therefore, multiple binding site fluorescent probes can realize their discrimination detection. For an NIR fluorescent probe, it is easier to realize in vivo imaging to promote the research of biothiols in clinical diagnosis. In our work, not only were multiple binding sites constructed in the compound but also NIR fluorophores were introduced. This enables the probe to not only efficiently distinguish detection of Cys/Hcy and GSH but also achieve fluorescence imaging in vivo. We believe this result is a milestone in the discrimination detection of biothiols.