Modular enzymatic biosensor based on electrolyte-gated organic field-effect transistor for glucose and urea sensing

Electrolyte-gated organic field-effect transistors (EGOFETs) have the potential to be versatile transducing devices for the realization of modular environmental monitoring and biomedical diagnostic sensor platforms. For the practical realisation the EGOFET offers several operation modes to transduce a specific analyte/receptor interaction into an easy to read out electrical response. Here we report on the interaction between the analyte (glucose and urea) using specific enzyme (glucose-oxidase and urease, respectively) based bioreceptor anchored to the EGOFET gate electrode rather than a binding/affinity device. The presented EGOFET-based enzymatic biosensor for glucose and urea displays a linear and analyte selective response in the range between 10− 6 and 10− 3 mol/L. Changes in the local ionic strength affect the Debye length which modulates the EGOFET responses through the electric double layer capacitance variation. The possibility of exchanging the modified gate electrode to detect specific analytes using the same EGOFET system allows the modular sensor which might be reused and applied for a broad range of applications.