Biology Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, Shandong Province, China.
Shandong Jinan Qilu Science Patent Office Ltd, Ji'nan 250014, Shandong Province, China.
Org Biomol Chem. 2020 Feb 26;18(8):1522-1549. doi: 10.1039/c9ob02561h.
Nitric oxide (NO) is an important gaseous signaling molecule related to various human diseases. To investigate the biological functions of NO, many strategies have been developed for real-time monitoring the NO levels in biological systems. Among these strategies, fluorescent probes are considered to be one of the most efficient and applicable methods owing to their excellent sensitivity and selectivity, high spatiotemporal resolution, noninvasiveness, and experimental convenience. Therefore, great efforts have been paid to the design, synthesis, and fluorescence investigation of novel NO fluorescent probes in the past several years. However, few of them exhibit practical applications owing to the low concentration, short half-life, and rapid diffusion characteristics of NO in biological systems. Rational design of NO fluorescent probes with excellent selectivity and sensitivity, low cytotoxicity, long-lived fluorescent emission, and low background interference is still a challenge for scientists all over the word. To provide spatial-temporal information, this article focuses on the progress made in the organic and metal complex-based NO fluorescent probes during the past five years. The key structural elements and sensing mechanisms of NO fluorescent probes are discussed. Some novel ratiometric, luminescence, and photoacoustic probes with low background interference and deep tissue penetrating ability are mentioned. All these probes have been used for imaging exogenous and endogenous NO in cells and animal models. More importantly, this article also describes the development of multi-functional NO fluorescent probes, such as organelle targeting probes, dual-analysis probes, and probe-drug conjugates, which will inspire the design of various functional fluorescent probes.
一氧化氮（NO）是一种与多种人类疾病相关的重要气态信号分子。为了研究 NO 的生物学功能，已经开发了许多策略来实时监测生物系统中的 NO 水平。在这些策略中，荧光探针由于其出色的灵敏度和选择性、高时空分辨率、非侵入性和实验便利性，被认为是最有效和适用的方法之一。因此，过去几年中，人们付出了巨大的努力来设计、合成和荧光研究新型 NO 荧光探针。然而，由于 NO 在生物系统中的浓度低、半衰期短和扩散迅速的特点，很少有探针具有实际应用价值。合理设计具有优异选择性和灵敏度、低细胞毒性、长荧光寿命和低背景干扰的 NO 荧光探针仍然是全世界科学家面临的挑战。为了提供时空信息，本文重点介绍了过去五年中基于有机和金属配合物的 NO 荧光探针的进展。讨论了 NO 荧光探针的关键结构元件和传感机制。提到了一些具有低背景干扰和深组织穿透能力的新型比率、发光和光声探针，这些探针已被用于细胞和动物模型中外源和内源性 NO 的成像。更重要的是，本文还描述了多功能 NO 荧光探针的发展，如细胞器靶向探针、双分析探针和探针药物偶联物，这将启发各种功能荧光探针的设计。
