Activatable NIR-II Fluorescence Probe for Highly Sensitive and Selective Visualization of Glutathione In Vivo

• Published in: Analytical chemistry (Washington) Vol. 93; no. 51; pp. 17103 - 17109
• Main Authors: Pan, Yuantao, Lei, Shan, Zhang, Jing, Qu, Junle, Huang, Peng, Lin, Jing
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 28.12.2021
• Subjects: analytical chemistry; Biomarkers; Chemistry; detection limit; Diagnostic Imaging; Fluorescence; Fluorescent Dyes; Fluorescent indicators; Glutathione; Humans; I.R. radiation; In vivo methods and tests; Near infrared radiation; Penetration depth; photostability; Probes; Selectivity; skeleton; Visualization
• ISSN: 0003-2700; 1520-6882; 1520-6882
• DOI: 10.1021/acs.analchem.1c04504

Visualization of glutathione (GSH) enables us to understand GSH-related pathophysiological processes in living subjects. Currently, in vivo visualization methods of GSH are based on visible or first near-infrared (NIR-I) window fluorescence (FL) probes, which possess limitations due to their low tissue penetration depth and strong tissue autofluorescence. Herein, we developed a GSH-activatable second near-infrared (NIR-II) window FL probe (denoted as LET-7) for highly sensitive and selective visualization of GSH in vivo. LET-7, composed of an anionic polymethylcyanide skeleton linked with a FL quenching group of 3,5-bis­(trifluoromethyl)­benzenethiol, can be specifically activated by GSH, thus triggering a significant NIR-II FL emission enhancement with excellent photostability, which enables us to efficiently distinguish GSH from closely related low-molecular-weight biothiols. The limit of detection of LET-7 for GSH was determined to be as low as 85 nM. Most intriguingly, the in vivo studies demonstrated that LET-7 showed high sensitivity and good selectivity toward GSH. Therefore, our study provides a solution to design activatable NIR-II FL probes for in vivo imaging of GSH and other disease-related biomarkers.