Latest generation glucose sensors use small-form wearables which provide continuous data. These
devices represent the commercial forefront aiming towards personalized and real-time point-of-care
biomedical applications. Currently, device lifetimes are limited due to unknown failure mechanisms and
ex-situ calibration strategies. Creating a method for in-situ sensor diagnostics will allow a bottom-up
approach for designing enzyme-supporting matrixes and calibration strategies inherent to biosensors. To
this end, this work seeks to enhance the understanding of performance, stability, and failure mechanisms
of biologically based electrochemical transistors using impedimetric measurements.
Here, we reveal the fundamental interplay between glucose oxidase loading and the electronic properties
of a commonly used PEDOT:PSS matrix as an encapsulating medium. Fundamental to these studies was
the discovery of conductivity enhancing strategies compatible with preserving enzyme activity. The
enzyme-embedded conductive polymer matrix was used in an organic electrochemical transistor probed
via electrochemical impedance (EI) to determine the causes of performance loss over sensor lifetimes.
Supporting spectroscopies aided in detailing film morphology and electrical property changes associated
with sensor behavior.