Uota Sisay, Hwang Bor-Jang, Butcher Raymond, Mullins Roger, Wachira James, Hijji Yousef, Abebe Fasil
Department of Chemistry, Morgan State University, 1700 E Cold Spring Ln, Baltimore, MD 21251 USA.
Department of Biology, Morgan State University, 1700 E Cold Spring Ln, Baltimore, MD 21251 USA.
Spectrochim Acta A Mol Biomol Spectrosc. 2025 Feb 5;326:125155. doi: 10.1016/j.saa.2024.125155. Epub 2024 Sep 21.
A new sensor based on Ethylbenzothiazolium-2-hydroxynaphthaldehyde conjugate-based fluorescent sensor, (E)-3-ethyl-2-(2-(2-hydroxynaphthalen-1-yl) vinyl) benzo[d]thiazol-3-ium iodide (SU-1) was designed and synthesized. The structure of SU-1 was confirmed by H NMR, C NMR, HRMS, and single crystal XRD spectral analysis. SU-1 displayed a colorimetric and fluorometric response in a DMSO:HO (1:1,v/v) matrix, changing color from pale yellow to colorless visible to the naked eye, accompanied by a ∼ 120 nm red-shift in the absorption spectra upon CN addition. This shift, due to formation of deprotonation followed by the nucleophilic attack on the benzothiazolium ring's double bond, disrupts π-conjugation, blocking intramolecular charge transfer within SU-1. However, competitive anions showed negligible interference while detecting CN. The Limit of detection for CN was determined to be 0.27 nM, significantly below the WHO's permissible CN concentration in drinking water (1.9 μM). Job's plot analysis shows that the binding stoichiometry of SU-1 to CN is a 1:1, with a stability constant (Ka) of 1.58 x 10 M. The sensor demonstrated practical applications in environmental water samples and fluorescence imaging of intracellular CN in CAD cell line.
设计并合成了一种基于乙基苯并噻唑啉-2-羟基萘醛共轭物的新型荧光传感器，即（E）-3-乙基-2-（2-（2-羟基萘-1-基）乙烯基）苯并[d]噻唑-3-碘鎓盐（SU-1）。通过¹H NMR、¹³C NMR、高分辨质谱（HRMS）和单晶X射线衍射光谱分析确定了SU-1的结构。SU-1在二甲基亚砜：水（1:1，v/v）基质中表现出比色和荧光响应，肉眼可见颜色从浅黄色变为无色，加入氰根（CN）后吸收光谱发生约120nm的红移。这种红移是由于去质子化形成后对苯并噻唑鎓环双键的亲核攻击，破坏了π共轭，阻断了SU-1分子内的电荷转移。然而，在检测CN时，竞争性阴离子的干扰可忽略不计。确定CN的检测限为0.27 nM，显著低于世界卫生组织规定的饮用水中CN的允许浓度（1.9 μM）。Job曲线分析表明，SU-1与CN的结合化学计量比为1:1，稳定常数（Ka）为1.58×10⁶ M。该传感器在环境水样和CAD细胞系细胞内CN的荧光成像中显示出实际应用价值。
