Highly sensitive and selective strategy for imaging Hg2+ using near-infrared squaraine dye in live cells and zebrafish. (October 2018)

• Record Type: Journal Article
• Authors: Wang, Guimei; Xu, Wenjian; Yang, Huanghao; Fu, Nanyan
• Is Part Of: Dyes and pigments. Volume 157(2018)
• Page Start: 369
• Page End: 376
• Publication Date: 2018-10
• Subjects: Squaraine -- Self-assembly -- Double quenching effect -- Hg2+-triggered disaggregation -- Fluorescent probe -- Bioimaging; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2018.05.016
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: This article describes the rational design and synthesis of a monothiosquaraine (MTSQ ) fluorescent Hg 2+ probe that exhibits near-infrared fluorescence, ultrahigh brightness, fast response, high sensitivity and excellent selectivity. Utilizing the strategy of the incorporation of the heavy atom effect and self-assembly caused quenching, the background fluorescence ofMTSQ was greatly lowered and the sensitivity in PBS buffer solution was highly enhanced with a very low limit of detection (LOD = 1.2 nM). Systematic studies revealed excellent selectivity and specificity for Hg 2+ over other thiophilic metal ions such as Ag +, Pb 2+, and Cd 2+ . The mechanistic investigation indicates that self-assembly and desulfurization ofMTSQ are responsible for Hg 2+ -triggered significantly higher fluorescence enhancement. With high sensitivity, optimal pH range of 3–7, weak background, good water-solubility and low cytotoxicity, MTSQ therefore can be applied for imaging Hg 2+ in live cells and zebrafish. The very simple but effective strategy reported here can provide a more convenient approach for designing NIR probes. Graphical abstract: Highlights: A squaraine based fluorescent probe of Hg 2+ has been designed and synthesized. Heavy atom effect and self-assembly have been incorporated in Hg 2+ sensing. The fluorescent probe shows excellent selectivity and high sensitivity. The probe has been applied in live cell and zebra fish imaging. The sensing mechanism has been discussed.