Photoswitchable fluorescent nanoparticles: preparation, properties and applications.

This minireview highlights recent advances of research dedicated to photoswitchable fluorescent nanoparticles and their applications. Recently, several strategies have been developed to synthesize nanoparticles with optically switchable emission properties: either fluorescence on/off or dual-alternating-color fluorescence photoswitching. The underlying mechanisms of fluorescence photoswitching enable many different types of photoswitchable fluorescent nanoparticles to change fluorescence colors, thus validating the basis of the initial photoswitching design. Among all possible applications, the usage of photoswitchable fluorescent nanoparticles to empower super-resolution fluorescence imaging and to label biological targets was subsequently reviewed. Finally, we summarize the important areas regarding future research and development on photoswitchable fluorescent nanoparticles.