张晓兵-袁林课题组科研成果|具有优异双光子特性的功能化TPCs荧光染料-百灵威

双光子成像是生物医学研究和临床诊断的新兴工具。电子供体-受体（D–A）型分子是应用最广泛的双光子支架，然而由于溶剂化淬灭效应使这些染料的应用受到了限制，湖南大学张晓兵-袁林课题组提出了氢键诱导荧光增强（Hydrogen-bond Induced Enhanced Emission, HIEE）的反溶剂化荧光染料发展新策略，构建了具有反溶剂化效应的双光子荧光染料——TPCs荧光染料。^[1]

反溶剂化效应：有效解决染料极性荧光淬灭难题；
更适合应用于双光子荧光生物成像：TPCs荧光染料在水溶液中会表现出强荧光和大的双光子吸收截面，荧光会随着溶剂极性增强而增强。

图1 A) Structures of TPC1–3. B) Normalized fluorescence intensities of Acedan-NH<sub>2</sub> , Ans, Naph-NH<sub>2</sub> , and TPC1–3 (5 mm) in different solvents DCM=CH<sub>2</sub>Cl<sub>2</sub> . C),D) Fluorescent photographs of TPC3 and Acedan-NH<sub>2</sub> (5 mm) in MeCN–PBS buffer mixtures under 365 nm excitation.<sup>[1]</sup>

图1 A) Structures of TPC1–3. B) Normalized fluorescence intensities of Acedan-NH₂ , Ans, Naph-NH₂ , and TPC1–3 (5 mm) in different solvents DCM=CH₂Cl₂ . C),D) Fluorescent photographs of TPC3 and Acedan-NH₂ (5 mm) in MeCN–PBS buffer mixtures under 365 nm excitation.^[1]

在此荧光染料基础上，张晓兵-袁林课题组构建了新型双光子H₂S探针TPC-N₃，首次成功实现在肝硬化过程中气体信号分子H₂S的成像检测。同时揭示了H₂S在肝硬化前期起着重要的自我修复作用。

图2 Two-photon imaging of TPC-N<sub>3</sub> (10 mm) in liver tissue of cirrhotic mice: A) Normal mice liver tissue only. Inset: the chemical structure of TPC-N<sub>3</sub> . B) Normal mice liver tissue with TPC-N<sub>3</sub> , C)–I) mice with CCl4 treatment after 1 to 7 weeks, liver tissue extracted then incubated with TPC-N<sub>3</sub> . Excitation: 810 nm. Emission: 500–560 nm. Scale bar: 150 mm. J) Quantification of cystathionine g lyase (CSE) levels in normal and cirrhosis liver tissue by ELISA. K) Serum ALT levels in normal and cirrhosis mice. <sup>[1]</sup>

图2 Two-photon imaging of TPC-N₃ (10 mm) in liver tissue of cirrhotic mice: A) Normal mice liver tissue only. Inset: the chemical structure of TPC-N₃ . B) Normal mice liver tissue with TPC-N₃ , C)–I) mice with CCl4 treatment after 1 to 7 weeks, liver tissue extracted then incubated with TPC-N₃ . Excitation: 810 nm. Emission: 500–560 nm. Scale bar: 150 mm. J) Quantification of cystathionine g lyase (CSE) levels in normal and cirrhosis liver tissue by ELISA. K) Serum ALT levels in normal and cirrhosis mice. ^[1]