Creation of a point-of-care therapeutics sensor using protein engineering, electrochemical sensing and electronic integration.

Point-of-care sensors, which are low-cost and user-friendly, play a crucial role in precision medicine by providing quick results for individuals. Here, we transform the conventional glucometer into a 4-hydroxytamoxifen therapeutic biosensor in which 4-hydroxytamoxifen modulates the electrical signal generated by glucose oxidation. To encode the 4-hydroxytamoxifen signal within glucose oxidation, we introduce the ligand-binding domain of estrogen receptor-alpha into pyrroloquinoline quinone-dependent glucose dehydrogenase by constructing and screening a comprehensive protein insertion library.