Diverse Fluorescent Probe Concepts for Detection and Monitoring of Reactive Oxygen Species

World-wide research on reactive oxygen species (ROS) continues to reveal new information about the role and impact of ROS on human health and disease. ROS are generated in live cells as a byproduct of aerobic metabolism. Physiological concentrations of cellular ROS are important for signaling and homeostasis, but excessive generation of ROS causes apoptotic and necrotic cell death and various health disorders. Fluorescence technology is a powerful tool to detect, monitor, and image cellular ROS. The present review provides an overview of diverse organic dye-based fluorescent probe concepts that involve modifications of traditional fluorescent dyes utilizing basic principles of dye chemistry and photophysics. Fluorescence responses of the probes and their specificity towards ROS are discussed through analyses of their photophysical and photochemical parameters. We also provide an outlook on future directions of ROS-responsive fluorescent dyes, which could enable the design and development of advanced probes for gaining deeper insights into redox biology.