A two-photon fluorescent probe for endogenous superoxide anion radical detection and imaging in living cells and tissues

• Published in: Sensors and actuators. B, Chemical Vol. 250; pp. 259 - 266
• Main Authors: Lu, Danqing, Zhou, Liyi, Wang, Ruowen, Zhang, Xiao-Bing, He, Lei, Zhang, Jing, Hu, Xiaoxiao, Tan, Weihong
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.10.2017; Elsevier Science Ltd
• Subjects: Anions; Atoms & subatomic particles; Biocompatibility; Biosensors; Cell imaging; Cells; Cells (biology); Endogenous O2− detection and imaging; Fluorescence; Fluorescent indicators; Image resolution; Light; Radiation detectors; Response time; Stability; System effectiveness; Technical services; Tissue imaging; Tissues; Toxicity; Turn-on response; Two-photon fluorescent probe; Variation; Endogenous O2− detection and imaging; Two-photon fluorescent probe; Cell imaging; Tissue imaging; Turn-on response
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2017.04.041

•A Two-photon fluorescent probe based on non-redox strategy for endogenous O2− detection has been successfully designed and synthesized for intracellular biosensing and bioimaging.•The probe displayed excellent in vitro analytical performance, as well as two-photon bioimaging of endogenous O2− in live cells and tissue slices.•By taking advantage of the reported two-photon fluorescent probe, further understanding of the roles of O2− in biological and pathological events is anticipated. Superoxide anion radical (O2−), the “primary” reactive oxygen species (ROS) in living systems, is linked to a variety of physiological and pathological processes. Therefore, developing an effective strategy to monitor the fluctuation of O2− in biological systems is of great importance. This paper describes a new turn-on two-photon fluorescent probe for endogenous O2− detection and imaging, which was rationally designed and synthesized via a non-redox strategy. In the presence of O2−, the probe exhibited notable fluorescence enhancement (∼235-fold) with a low detection limit down to 1nM, indicating a high signal-to-background ratio and excellent sensitivity. In addition, short response time, good biocompatibility, low cytotoxicity, long-term stability against light illumination, specificity to O2− over general reductants, and pH stability were demonstrated, indicating that the requirements for cellular O2− determination are met. Furthermore, the probe was successfully applied in two-photon fluorescence imaging of endogenous O2− in living cells and tissues and showed high imaging resolution and a deep-tissue imaging depth of ∼150μm, illustrating the promising potential for practical applications in complex biosystems and providing a valuable theoretical basis and technical support for the study of physiological and pathological functions of O2−.