Abstract: The present disclosure relates to fluorescent biosensors and methods of use thereof. In particular, provided herein is a genetically encoded fluorescent indicator (GEFI) comprising a circular-permuted fluorescent protein (cpFP) and an inhibitory molecule bound to the cpFP. In the basal state, the inhibitory molecule prevents fluorescence from the circular-permuted fluorescent protein. Upon conformational change and/or cleavage of the bond between the inhibitory molecule and the cpFP, the cpFP is disinhibited, thereby permitting fluorescence from the cpFP. The biosensors described herein may be used in methods for detecting a variety of cell-signaling events.