Split trehalase as a versatile reporter for a wide range of biological analytes.

In health care, biosensors are envisioned as universal diagnostic devices with AAAA characteristics (i.e., available for anything, anywhere, anytime, to anyone). Despite numerous attempts to develop such a diagnostic device, none have managed to fulfill all four criteria and be commercialized. Glucometers, the most successful class of biosensor currently marketed monitor blood glucose concentrations. Their performance in clinical samples, including sensitivity and specificity, has been optimized and they are small and relatively inexpensive. We aimed to develop a technology that uses this existing biosensor, but adds versatility in detection of a wide range of analytes. Herein, we report the periplasmic trehalase of E. coli as a novel split enzyme reporter capable of converting a wide variety of analytes into glucose. Conditional complementation of trehalase fragments induced by detection of analytes, resulting in trehalose hydrolysis and glucose production, was used to detect antibodies and bacterial cells. We also demonstrated retention of split TreA activity in undiluted clinical samples. In conclusion, a trehalase-based biosensor platform offers a versatile and convenient method for point-of-care applications as it does not require sample preparation or handling and can be integrated with existing glucometers or sensors.