Redox-controlled fluorescent sensor for highly reactive oxygen species detection and cell imaging based on dihydrolipoic acid functionalized carbon quantum dots

• Published in: Journal of luminescence 2021-06, Vol.234, p.117998, Article 117998
• Main Authors: Zhang, Ruxia, Fan, Zhefeng
• Format: Article
• Language: English
• Subjects: Carbon quantum dots; Cell imaging; Dihydrolipoic acid; Fluorescent sensor; Reactive oxygen species; Redox
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2021.117998

A novel redox-controlled fluorescent sensor for the detection of highly reactive oxygen species (hROS) was developed based on the unique green fluorescence emission of dihydrolipoic acid functionalized carbon quantum dots (DHLA@N-CQDs). Given the excellent redox characteristic between the disulfide bonds (S–S) and thiol (R-SH), the sensor was designed by bonding N-CQDs and DHLA under the action of coupling agents. When hROS was introduced into the sensing system, a large number of S–S gathered between DHLA@N-CQDs can effectively inhibit the fluorescence of probe. In addition, the as-prepared fluorescent sensor can sense hydroxyl radicals (·OH) and hydrogen peroxide (H2O2) in different response ranges, which ensures a high selectivity for hROS detection. Furthermore, the sensor system has been successfully utilized to detect the H2O2 in human saliva samples and the fluorescence imaging of ·OH in HeLa cells, exhibiting the feasibility of fluorescent sensors in practical applications. Scheme 1. Sensing mechanism diagram of fluorescent switch sensor to hROS. [Display omitted] •A novel redox-controlled fluorescent sensor was developed.•The functionalization of dihydrolipoic acid enables the probe to transform from blue to green light.•Hydroxyl radicals (·OH) and hydrogen peroxide (H2O2) can be sensed in different response ranges.•Fluorescent sensor was used to detect the H2O2 in human saliva samples and the fluorescence imaging of ·OH in HeLa cells.