Recent developments of fluorescent proteins and biosensors driven by cross-disciplinary insights

Since the discovery and application of green fluorescent protein for use as an optical tag, fluorescent proteins (FPs) have changed the way we observe biological signals and processes. FP and fluorescent biosensor design has continued to advance, facilitated by new technologies and developments in chemistry, physics, engineering and screening technologies. We summarize some of the recent developments in FP engineering, focusing on insights that have led to improved photostability or longer wavelengths, among other improvements, highlighting mScarlet as a case study. We also discuss the engineering of new fluorescent biosensors, focusing on the ways in which screening, quantitative imaging, spatial resolution and multiplexing have been improved in recent years. Finally, we conclude with a perspective on what the future holds for the next generation of FPs and biosensors.