A novel dual-function fluorescent probe for the detection of cysteine and its applications in vitro

• Published in: Talanta (Oxford) 2024-05, Vol.272, p.125769-125769, Article 125769
• Main Authors: Zhou, Lipan, Yang, Tengao, Zhang, Tingrui, Song, Zhiguang, Feng, Guodong
• Format: Article
• Language: English
• Subjects: Bioimaging; Colorimetry - methods; Cyclization; Cysteine; Cysteine - analysis; Dual-function; Fluorescent Dyes; Fluorescent probe; HeLa Cells; Humans; Limit of Detection; Smartphones; Spectrometry, Fluorescence
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2024.125769

A fluorescent probe of both colorimetric and ratiometric type for highly selective and sensitive detection of Cys (cysteine) is very important in biological analysis. In this work, a new colorimetric and ratiometric fluorescent probe ((E)-2-(2-(5-(4-(acryloyloxy)phenyl)furan-2-yl)vinyl)-3-methylbenzo[d]thiazol-3–ium iodide, LP-1) was designed and synthesized for the detection of Cys. The reaction mechanism of LP-1 toward Cys involves a conjugate addition reaction between Cys and the α,β-unsaturated carbonyl group, leading to the formation of an intermediate thioether, followed by intramolecular cyclization to produce the desired compounds LP-1-OH. At this point, the ICT process is activated, significantly increasing the fluorescence intensity of the molecules. Meanwhile, LP-1 is highly selective and sensitive to Cys identification under optimized experimental conditions. LP-1 shows a good linear relationship in the range of Cys concentration from 0.40 μM to 40 μM (R2 = 0.9942) and the limit of detection (LOD) of Cys is 0.19 μM. In addition, we have developed a simple, portable and low-cost smartphone-based high-sensitivity Cys detection method based on naked eye obvious color detection. LP-1 also has low cell toxicity and can be successfully used for biological imaging of Cys, suggesting that it is a promising biological application tool for Cys detection. [Display omitted] •Dual-function fluorescent probe with colorimetric and ratiometric properties was designed and synthesized.•This probe showed exceptional selectivity and sensitivity in Cys detection with a low LOD (0.19 μM).•A novel smartphone-based approach for Cys detection based on naked-eye color change was developed.•The probe was suitable for Cys bioimaging in cells with low cytotoxicity.