Kim Na Yoon, Fortibui Maxine Mambo, Lee Min Hee
Department of Chemistry, Chung-Ang University, Seoul, 06974, South Korea.
Department of Chemistry, Chung-Ang University, Seoul, 06974, South Korea.
Anal Chim Acta. 2025 Oct 1;1369:344363. doi: 10.1016/j.aca.2025.344363. Epub 2025 Jul 3.
Reactive oxygen species (ROS) are highly reactive molecules that play pivotal roles in various cellular functions such as signaling, immune responses, and metabolic regulation. While they are essential in normal physiological processes, excessive ROS accumulation leads to oxidative stress, which damages cellular structures, including lipids, proteins, and DNA, contributing to diseases like cancer, neurodegeneration, and cardiovascular disorders. Therefore, the development of effective detection strategy for the selective detection of ROS, particularly superoxide (O) and hypochlorite (ClO), is crucial for understanding their roles in cellular processes.
In this study, we introduce an acetoxy-substituted tetraphenyl imidazole (AcOPI) as a fluorescence probe specifically designed to detect superoxide (O) and hypochlorite (ClO) through a unique combination of aggregation-induced emission (AIE) and excited-state intramolecular proton transfer (ESIPT). The probe demonstrates a remarkable 96-fold fluorescence enhancement upon ROS exposure, with a large Stokes shift (Δλ = 145 nm) that minimizes interference from background fluorescence. Additionally, AcOPI exhibits low self-quenching and high aqueous compatibility, which are advantageous features for its application in biological systems. These properties make AcOPI a highly sensitive and selective tool for ROS detection in aqueous environments. These results could be applied to follow-up research focused on developing fluorescence probes that absorb and emit detectable visible light for spatiotemporal and real-time detection in living systems.
The successful development of AcOPI as a fluorescent probe for detecting superoxide and hypochlorite offers a promising strategy for monitoring ROS under both physiological and environmental conditions. Owing to its high sensitivity, large Stokes shift, and excellent aqueous compatibility, AcOPI enables real-time ROS imaging and detection, underscoring its potential for diagnostic applications in ROS-related diseases. This study further suggests a potential application in elucidating the link between chronic inflammation and cancer by exploring the mechanisms of ROS interactions during disease progression. Applying our methodology to chronic inflammation models may help clarify the integrated ROS signaling pathways involved in tumor development. Beyond its medical relevance, AcOPI also shows strong potential for environmental monitoring of aquatic organisms subjected to oxidative stress induced by pollutants such as heavy metals, pesticides, and disinfectants. Although AcOPI demonstrated promising performance in aqueous systems, several challenges remain for in vivo applications. The limited tissue penetration of visible light may restrict the use of these probes for deep-tissue imaging or targeted delivery.
活性氧（ROS）是高反应性分子，在信号传导、免疫反应和代谢调节等各种细胞功能中发挥关键作用。虽然它们在正常生理过程中必不可少，但过量的ROS积累会导致氧化应激，损害包括脂质、蛋白质和DNA在内的细胞结构，引发癌症、神经退行性疾病和心血管疾病等疾病。因此，开发一种有效的检测策略来选择性检测ROS，特别是超氧阴离子（O）和次氯酸盐（ClO），对于理解它们在细胞过程中的作用至关重要。
在本研究中，我们引入了一种乙酰氧基取代的四苯基咪唑（AcOPI）作为荧光探针，专门设计用于通过聚集诱导发光（AIE）和激发态分子内质子转移（ESIPT）的独特组合来检测超氧阴离子（O）和次氯酸盐（ClO）。该探针在暴露于ROS时显示出显著的96倍荧光增强，具有大的斯托克斯位移（Δλ = 145 nm），可最大限度地减少背景荧光的干扰。此外，AcOPI表现出低自猝灭和高水相容性，这是其在生物系统中应用的有利特性。这些特性使AcOPI成为水性环境中ROS检测的高灵敏度和选择性工具。这些结果可应用于后续研究，重点是开发在生物系统中用于时空和实时检测的吸收和发射可检测可见光的荧光探针。
成功开发出用于检测超氧阴离子和次氯酸盐的荧光探针AcOPI，为在生理和环境条件下监测ROS提供了一种有前景的策略。由于其高灵敏度、大斯托克斯位移和出色的水相容性，AcOPI能够进行实时ROS成像和检测，突出了其在ROS相关疾病诊断应用中的潜力。本研究进一步表明，通过探索疾病进展过程中ROS相互作用的机制，在阐明慢性炎症与癌症之间的联系方面具有潜在应用。将我们的方法应用于慢性炎症模型可能有助于阐明肿瘤发生过程中涉及的综合ROS信号通路。除了其医学相关性外，AcOPI在对受重金属、农药和消毒剂等污染物诱导的氧化应激影响的水生生物进行环境监测方面也显示出强大潜力。尽管AcOPI在水性系统中表现出有前景的性能，但在体内应用方面仍存在一些挑战。可见光有限的组织穿透性可能会限制这些探针用于深部组织成像或靶向递送。
