Ultra-sensitive label-free DNA detection based on n-type accumulation mode vertical organic electrochemical...

Herein, we present an ultrasensitive DNA detection platform based on n-type accumulation-mode vertical organic electrochemical transistors (vOECTs) for the first time. The vOECTs utilize poly(benzimidazobenzophenanthroline) (BBL) as the n-type organic semiconductor channel, operating in accumulation mode with low power consumption and ultrahigh transconductance (up to 53.7 mS). DNA probes were immobilized on Au gate electrodes via Au-S bonds, followed by 6-mercapto-1-hexanol (MCH) blocking to minimize nonspecific adsorption. Target DNA hybridization induces interfacial charge redistribution and electrical double-layer (EDL) modulation, amplifying current responses through the vOECT's high transconductance. The platform achieves an exceptional sensitivity of 155.91 μA/dec-31-fold higher than state-of-the-art DNA sensors-and an ultralow detection limit of 1.07 aM. Notably, the sensor enables label-free, amplification-free detection with rapid response and excellent stability. This work establishes a novel approach for high-precision nucleic acid analysis in biomedical applications.