Development of Unique Xanthene–Cyanine Fused Near‐Infrared Fluorescent Fluorophores with Superior Chemical Stability for Biological Fluorescence Imaging. Issue 2 (11th November 2014)

• Record Type: Journal Article
• Authors: Chen, Hua; Lin, Weiying; Cui, Haijun; Jiang, Wenqing
• Is Part Of: Chemistry. Volume 21:Issue 2(2015)
• Page Start: 733
• Page End: 745
• Publication Date: 2014-11-11
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201404718
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The development of near‐infrared (NIR) functional fluorescent dyes has gained increasing attention over the last few decades. Herein, we describe the development of a unique type of xanthene–cyanine fused NIR fluorophores, <bold>XC</bold> dyes, formed by reacting chloro‐substituted cyanine with resorcin or its analogues under anhydrous conditions. <bold>XC</bold> dyes are a hybrid of cyanine and xanthene. The preliminary mechanistic studies indicate that the formation of <bold>XC</bold> compounds likely includes a sequence of cyclization and oxidation. <bold>XC</bold> dyes have absorption and emission in the NIR region, and their fluorescence properties can be controlled by modifications of the key hydroxyl and amine groups. The novel <bold>XC</bold> NIR dyes are advantageous over previously developed merocyanine dyes NIR dyes in their chemical stability against strong nucleophiles. Quantum chemical calculations reveal that the distinct properties of <bold>XC</bold> and <bold>HD</bold> dyes can be attributed to their structural differences. By taking advantage of the superior properties of <bold>XC</bold> dyes, we have further constructed a new NIR fluorescent probe, <bold>XC‐H<sub>2</sub>S</bold>, which is capable of monitoring both the concentration‐ and time‐dependent variations of H<sub>2</sub>S in living animals, highlighting the value of <bold>XC</bold> NIR dyes. We expect that the unique <bold>XC</bold> NIR dyes developed herein will find broader applications than <bold>HD</bold> NIR dyes as fluorescent platforms for the development of a wide variety of NIR fluorescent probes, in particular, those suitable for targets of interest that have strong nucleophilic character.</p> </abstract>