Nanogap-Based Electrical PNA Chips for the Detection of Genetic Polymorphism of Cytochrome P450 2C19

Abstract

PNA chips for the detection of the genetic polymorphism of Cytochrome P450 2019 (CYP2C19), a well-known enzyme related to the metabolism of therapeutic drugs, were electrically-interfaced with interdigitated nanogap electrodes (INEs). The average gap distance and effective length of the INEs were about similar to 70 nm and similar to 140,mu m, respectively. Those INEs having the aspect ratio of about 2000, were prepared by the combination of the photolithography (for the formation of initial electrodes) and the surface-catalyzed chemical deposition (for the gap narrowing), without the e-beam lithography. The PNA probes for the detection of CYP2C19 were immobilized in the gap region of INEs via Schiff base formation. The I-V characteristics clearly showed a sharp increase in the conductance between the nanogap electrodes upon the PNA-DNA hybridization, followed by the adsoprtion of functionalized Au nanoparticles. Four different target DNAs for the diagnosis of CYP2C19 polymorphism were successfully detected and discriminated with the INE-based PNA chips.