Highly Enhanced Sensing Performances of Si-Based Electrolyte-Gated Transistor (EGT) Using Silver Nanowire Coating Method in Chikungunya Detection

Silver nanowire (AgNW) coating was applied to the gate surface of silicon-based electrolyte-gated transistors (EGTs) by spray coating and lift-off patterning to enhance biosensing performance. The intrinsic electrical properties of the device remained largely unaffected following AgNW deposition. After aptamer immobilization, threshold voltage variations were observed across different AgNW coating durations, indicating that the AgNW layer facilitates increased receptor density and improved sensitivity. The lumped-capacitive model was employed to calculate the dipolar and capacitive contributions. In the detection of Chikungunya virus (CHIKV), the AgNW-coated EGT (EGT-AgNW) demonstrated a 230% increase in sensitivity and achieved a limit of detection (LOD) as low as 430 pg/mL, approximately 200× lower than that of uncoated conventional EGTs. Furthermore, the sensor showed high selectivity against other mosquito-borne tropical viruses, such as dengue, Zika, and yellow fever (YF). These results indicate the potential of EGT-AgNW as low-cost, high-performance biosensing platforms capable of detecting CHIKV and other biomarkers at ultralow concentrations.