Light controlled imaging probes for intracellular target recognition: photochromism as a tool to enhance sensing precision

Chemosensors and imaging probes have been the focus of significant research interest over the past few decades. In part due to ease of preparation and simplicity in manipulation, fluorescent probes have been extensively used for biomedical applications. When used for in vitro cell imaging, the fluorescent probes tend to be passively internalised by cells and then bind or react with the intracellular analyte of interest leading to a fluorescence output signal. Nevertheless, several problems remain to be solved including biological autofluorescence, probe destruction before reaching the in vivo target and the failure to localise in the target cell of complex biological systems.