Responsive fluorescent probes for cellular microenvironment and redox small biomolecules

The living system is critically depended on the inner microenvironment and redox small biomolecules to maintain the normal physiological processes. Consequently, tracing and monitoring the functional mechanism of the microenvironment and redox small biomolecules remain of extraordinary significance. Fluorescent probes have emerged for bearing the important tasks of biosensing and bioimaging with superior fluorescence signal and superb targeting specificity. In this review, we focus on the responsive fluorescent probes of microenvironment-related parameters of pH, viscosity and hypoxia, and redox small biomolecules of the reactive oxygen species, reactive nitrogen species, reactive sulfur specie, respectively. Each category is firstly devoted generally functions of the target molecule properties, and then discuss the design strategy according to the specific recognition groups, as well as biological applications. We hope our review will provide useful guidance in development advanced fluorescence probe for monitoring the microenvironments and redox small biomolecules to reveal their special biological processes.