An "on-off-on" selective fluorescent probe based on nitrogen and sulfur co-doped carbon dots for detecting Cu and GSH in living cells

• Published in: Analytical methods Vol. 12; no. 42; pp. 511 - 5119
• Main Authors: Wei, Shanshan, Li, Tinghua, Zhang, Xinyu, Zhang, Hongyuan, Jiang, Chunzhu, Sun, Guoying
• Format: Journal Article
• Published: 05.11.2020
• ISSN: 1759-9660; 1759-9679
• DOI: 10.1039/d0ay01662d

The abnormal level of Cu 2+ or GSH can cause variety of neurodegenerative diseases in humans. Thus, the selective and sensitive detection of Cu 2+ and GSH has inspired intensive research efforts in biological sample analysis fields. Herein, an "on-off-on" fluorescent probe based on nitrogen and sulfur co-doped carbon dots (N,S-CDs) has been successfully prepared for the detection of Cu 2+ and GSH. The "turn-off" process of fluorescence in the presence of Cu 2+ ions was induced by forming a non-luminescent ground state complex due to the interaction between surface groups of the probe and Cu 2+ ions. Moreover, the strong coordination between GSH and Cu 2+ could destroy the structure of the complex and restore the fluorescence to "turn-on". This fluorescent probe had excellent selectivity and high sensitivity toward Cu 2+ and GSH with the limits of detection (LODs) of 38 nM and 41 nM. More importantly, the as-prepared N,S-CDs served as an efficient fluorescent probe for not only detecting Cu 2+ ions in lake water and tap water, and GSH in BSA solution, but also sensing Cu 2+ and GSH in living cells. Therefore, these N,S-CDs could be considered as a promising fluorescence probe candidate for environmental monitoring and biological imaging. Nitrogen and sulfur co-doped carbon dots (N,S-CDs) as a simple "on-off-on" fluorescent probe were applied for quickly detecting Cu 2+ ions and GSH in living cells.