Designs and applications of fluorescent protein-based biosensors.

Genetically encoded biosensors allow the noninvasive imaging of specific biochemical or biorecognition processes with the preservation of subcellular spatial and temporal information. Aequorea green fluorescent protein (FP) and its engineered variants are a critical component of genetically encoded biosensors, as they serve to provide a 'read-out' of the biorecognition event under investigation. The family of FP-based biosensors includes a diverse array of designs that utilize various photophysical characteristics of the FPs. In this review, we will discuss these designs and their read-outs through reviewing some of the recent works in this area.