pH-responsive copper-cluster-based dual-emission ratiometric fluorescent probe for imaging of bacterial metabolism

• Published in: Talanta (Oxford) 2021-01, Vol.221, p.121621, Article 121621
• Main Authors: Song, Shanliang, Zhao, Yue, Li, Yang, Yang, Xudong, Wang, Dong, Wen, Zhuoqi, Yang, Minghui, Lin, Quan
• Format: Article
• Language: English
• Subjects: Aggregation induced emission enhancement; Copper; Copper nanoclusters; Fluorescent Dyes; Hydrogen-Ion Concentration; Imaging of bacterial metabolism; Ratiometric fluorescent probe; Silicon Dioxide; Spectrometry, Fluorescence
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2020.121621

The profiling of bacterial metabolism is of great significance in practical applications. Therefore, the development of ultrasensitive and highly selective probe for bacterial metabolism detection and imaging is extremely desirable. Herein, a novel dual-emission pH-response bacterial metabolism detection and imaging probe is successfully developed. This probe consists of large-sized and easily separated SiO2 microspheres, copper nanoclusters (Cu NCs) with red emission, and carbon dots (CDs) with blue emission through in-situ self-assembly. In this system, the fluorescence of Cu NCs is sensitive to pH change due to their obvious aggregation-induced emission enhancement (AIEE) property, while the blue fluorescence of CDs remained almost stable. Therefore, red fluorescence and blue fluorescence are compounded with different fluorescence intensity at different pH values, and their fluorescence ratio is also different. By observation of composite fluorescence color, the visual colorimetric pH detection can be realized with the change of pH value of 0.2 units. Utilizing this system, we are able to detect bacterial metabolism with high signal-to-noise ratio, and it can also be used for bacterial metabolic imaging. Therefore, the pH-responsive Cu NCs-based dual-emission ratiometric fluorescent probe we constructed can provide new ideas for bacterial detection, antimicrobial sterilization, and biological imaging. [Display omitted] •Dual-emission Cu NCs–SiO2 @ CDs probe can visually detect pH changes by colorimetry.•The minimum pH change detected by the high sensitivity probe is 0.2 units.•The probe can detect the pH change of the bacterial metabolic system with high signal-to-noise ratio.•The probe can indicate the metabolism and reproduction of bacteria intuitively.