DPP-DTT Thin-Film-Transistor-based Glucose Sensor with Parylene C Gate Dielectric

Rapid and simple glucose detection is essential in healthcare, food safety, and environmental monitoring. This paper presents a flexible organic thin-film transistor glucose sensor using a PDPP2T-TT-OD (DPP-DTT) channel and Parylene C as both the substrate and gate dielectric. DPP-DTT is a high-mobility semiconductor material that enables simple and low-cost fabrication. Parylene C provides transparency, flexibility, and excellent chemical stability, thereby enhancing the durability of the sensor. The proposed glucose sensor was designed with a coplanar bottom-gate structure to enable direct contact between the DPP-DTT channel and the glucose solution. For the detection, the DPP-DTT channel was coated with glucose oxidase enzyme (GOx). Glucose solutions diluted in phosphate-buffered saline at the concentrations of 0 mM, 10 mM, and 25 mM were analyzed. The drift current that occurs during measurement and the time required for the sensor to rejuvenate are considered as limitations. Therefore, we performed calibration to improve the accuracy of the sensor. Consequently, the glucose sensors with the channel widths/lengths of 5000/50 (µm/µm) and 5000/75 (µm/µm) showed the sensitivities of 52.8946 nA/mM and 13.0305 nA/mM, respectively. This study highlighted the potential of a flexible and biocompatible glucose sensor using Parylene C and DPP-DTT. The proposed sensor is suitable for wearable health-monitoring applications.