Portable organic electrochemical transistor system for precision tracking of metformin pharmacokinetic profile.

Therapeutic drug monitoring (TDM) for type 2 diabetes medications like metformin is challenging due to the lack of rapid and sensitive methods. Standard assays are often inaccurate, time-consuming, and fail to capture real-time pharmacokinetic (PK) fluctuations. Here, we developed a portable organic electrochemical transistor (OECT) sensing system for continuous, real-time tracking of metformin levels. The laser-engraved OECT biosensor is functionalized with a specific Fe2O3 nanozyme on the gate electrode for electrocatalytic oxidation of metformin, enabling highly sensitive and selective detection. Seamless integration with a smartphone application and OECT system provides dynamic real-time metformin PK monitoring in vitro, fostering a pharmacologically informed approach to diabetes management. Our findings confirm the system's potential for home-care precision PK monitoring, paving the way for personalized diabetes care.