Organic Electrochemical Transistors for Biosensing Applications

The detection of low concentrations of biomarkers is crucial for early-stage medical diagnostics and intervention. Therefore, the development of biosensors with low LOD (Limit of Detection) is essential, as even the smallest quantities of biological markers can provide indications of disease progression. Organic electrochemical transistors (OECTs) have attracted great interest in the field of biosensors to be used as a transducer due to their unique properties, including low operating voltages, compatibility with aqueous environments, and intrinsic signal amplification. OECTs are three-terminal devices based on an organic mixed ionic-electronic semiconductor, such as PEDOT:PSS, which operate in contact with an electrolyte. During operation, the conductivity of the channel is electrochemically modulated by a gate voltage. For biosensing applications, the OECT is functionalized with biomolecules that specifically bind with the target analyte, this biorecognition event is translated into an amplified modulation of the channel current. Despite these advantages, lowering the LOD remains a key challenge for the reliable detection of analytes.