Synergistic Blending of Polythiophene/Silver Nanowires for Glucose Detection with Enhanced Sensitivity

Abstract

In the modern era, excess nutrition and uncontrolled diets have given rise to numerous chronic diseases, with diabetes emerging as a significant concern. Regular monitoring of blood sugar is essential for patients, but the invasive nature of blood sampling causes discomfort, deterring frequent testing. Hence, the development of noninvasive methods is imperative. This study utilizes a blend of poly(3-hexylthiophene) (P3HT) and silver nanowires (Ag NWs) to craft organic field-effect transistors (OFETs) for highly sensitive glucose detection. Ag NWs exhibit a strong affinity for oxygen molecules, easily forming silver oxide and preventing the oxygen doping issue in P3HT, resulting in improved OFET characteristics. Additionally, the Schottky barriers between P3HT/Ag NWs are highly sensitive to the released hydrogen ions from glucose oxidation. Consequently, devices fabricated through this methodology demonstrate exceptional sensitivity for detecting extremely low concentrations of glucose solutions. The blended device outperforms pure P3HT, with a 10-times increase in the on/off ratio (∼10⁴) and hole mobility (4 × 10^–3 cm²/(V s)). While detecting a 10 μM glucose solution (same level as saliva), the blended device’s normalized response (NR) soared to 24.62. Additionally, for a 20 mM glucose solution (the same level as blood), the NR of P3HT/Ag NWs surged to 428.49, much higher than that of the pure P3HT. The proposed glucose sensor showed a detection limit of 6 μM and a wide linear detection range (10 μM–20 mM), which encompasses the glucose levels found in both saliva and blood. These superior features demonstrate the potential application of P3HT/Ag NWs transistors in the fabrication of a high-performance glucose sensor. This study yields a highly promising avenue for noninvasive blood glucose detection.