Liu Jianhua, Yin Haoyuan, Shang Zhuye, Gu Pengli, He Guangjie, Meng Qingtao, Zhang Run, Zhang Zhiqiang
School of Chemical Engineering, University of Science and Technology Liaoning Anshan Liaoning Province 114051 P. R. China
College of Pharmacy, Jilin Medical University Jilin Province 132001 P. R. China.
RSC Adv. 2022 May 26;12(25):15861-15869. doi: 10.1039/d2ra01048h. eCollection 2022 May 23.
Hypochlorous acid (HOCl) and sulfur dioxide derivatives (SO /HSO ) play critical roles in complex signal transduction and oxidation pathways. Therefore, it is meaningful and valuable to detect both HOCl and SO derivatives in biosystems by a fluorescence imaging assay. In this work, we developed a red-emitting fluorescent probe (DP) by the condensation of malononitrile and phenothiazine derivatives through a C[double bond, length as m-dash]C double bond. DP was designed with a donor-π-acceptor (D-π-A) structure, which enables absorption and emission in the long wavelength region. In the presence of HOCl, specific oxidation of the thioether of phenothiazine in DP to a sulfoxide derivative (DP[double bond, length as m-dash]O) occurs, resulting in a hypochromic shift (572 nm to 482 nm) of the absorption spectra and "OFF-ON" response of the maximum emission at 608 nm. After the activation of the C[double bond, length as m-dash]C double bond by oxidation, DP[double bond, length as m-dash]O reacts specifically with SO /HSO a 1,4-nucleophilic addition reaction leading to a decrease in the intensity of the absorption and emission spectra, which enabled the realization of sequential detection of HOCl and SO /HSO by a single fluorescent probe. The detection limits of DP for HOCl and SO /HSO were calculated to be 81.3 nM and 70.8 nM/65.1 nm, respectively. The results of fluorescence microscopic imaging indicated that DP shows potential for the detection of intracellular HOCl and SO /HSO . Using adult zebrafish and nude mice as live animal models, DP was successfully used for the fluorescence imaging of HOCl and SO /HSO .
次氯酸（HOCl）和二氧化硫衍生物（SO₂/HSO₃⁻）在复杂的信号转导和氧化途径中发挥着关键作用。因此，通过荧光成像分析在生物系统中同时检测HOCl和SO₂衍生物具有重要意义和价值。在这项工作中，我们通过丙二腈和吩噻嗪衍生物通过C═C双键缩合开发了一种发红光的荧光探针（DP）。DP设计为供体-π-受体（D-π-A）结构，使其能够在长波长区域吸收和发射。在HOCl存在下，DP中吩噻嗪的硫醚特异性氧化为亚砜衍生物（DP═O），导致吸收光谱发生减色位移（从572 nm到482 nm）以及608 nm处最大发射的“关-开”响应。通过氧化激活C═C双键后，DP═O与SO₂/HSO₃⁻发生特异性反应，通过1,4-亲核加成反应导致吸收和发射光谱强度降低，从而实现了用单一荧光探针顺序检测HOCl和SO₂/HSO₃⁻。DP对HOCl和SO₂/HSO₃⁻的检测限分别计算为81.3 nM和70.8 nM/65.1 nm。荧光显微镜成像结果表明，DP在检测细胞内HOCl和SO₂/HSO₃⁻方面具有潜力。以成年斑马鱼和裸鼠作为活体动物模型，DP成功用于HOCl和SO₂/HSO₃⁻的荧光成像。
