Enhancing the Sensitivity of Electrolyte-Gated FET Biosensors via AC Voltage System to Overcome Debye Screening Effect
발표자
이주혁 (경기대학교 화학과)
연구책임자
하영근 (경기대)
초록
내용
Electrolyte-gated field-effect transistor (EGFET) biosensors offer high sensitivity in biomolecule detection, but their performance degrades in high-ionic-strength environments due to Debye screening. This study introduces an AC voltage modulation strategy to suppress ionic shielding by disrupting electrical double layer (EDL) formation. The biosensor was fabricated using an amorphous indium–gallium oxide (IGO) channel and functionalized with a tau-targeting aptamer via APTES and glutaraldehyde. Upon applying AC voltage together with a DC bias, EDL formation was weakened, thereby extending the effective charge detection range. Compared to DC-only sensing, the AC-assisted approach achieved stronger signal responses under identical ionic conditions. This work provides a promising strategy to overcome limitations in FET biosensor sensitivity under physiological environments and demonstrates its potential for reliable biomarker detection.