Immobilization of Probe DNA on Ta₂O₅ Thin Film and Detection of Hybridized Helix DNA using IS-FET

Abstract

We demonstrated developments of a non-labeling DNA (deoxyribonucleic acid) sensor by using a commercially available ion-sensitive field-effect transistor (IS-FET). A single strand DNA was immobilized on a Ta2O5 thin film on a gate electrode in the IS-FET, and the surface of the thin film was confirmed by XPS measurements. The results indicated that the DNA was immobilized on the Ta2O5 thin film. To detect the hybridization of DNA, we carried out measurements of I drain-V gs properties of IS-FETs immobilized by ss-DNA and ds-DNA hybridized by complemental target DNA. Then, the difference in threshold voltage was evaluated to be about 10 mV, and the amount of immobilized DNA as 6.3×107 [molecules/cm2]. Consequently, the non-labeling IS-FET DNA sensor is expected to be a novel measurement tool for diagnosing diseases.

Electrochemical processes and mechanistic aspects of field-effect sensors for biomolecules

“…Single-stranded DNA can be immobilized on the surface of FETs and maintain its ability to hybridize with complementary strands. 65,66 The two strands of DNA contain complementary elements (adenine-thymine and cytosine-guanine). The target single-stranded DNA (ssDNA) is identified by a probe ssDNA immobilized on the sensitive surface.…”

“…65,66 The two strands of DNA contain complementary elements (adenine–thymine and cytosine–guanine). The target single-stranded DNA (ssDNA) is identified by a probe ssDNA immobilized on the sensitive surface.…”

AlGaN/GaN HEMT And ZnO nanorod-based sensors for chemical and bio-applications

“…Electrical detection of hybridization using semiconductor based field effect transistors (FETs) have been reported previously (41)(42)(43)(44) . Baur et al detected DNA hybridization on a functionalized GaN surface with fluorescence labeled DNA (44) .…”

Immobilization of Target-Bound Aptamer on Field Effect Transistor Biosensor to Improve Sensitivity for Detection of Uncharged Cortisol

“…1 Thus, FET biosensors have the potential to directly detect target molecules without the need for a labeling process. [2][3][4] However, uncharged molecules do not affect the charge density on the gate surface by adsorption, which results in no shift in FET characteristics. To overcome this challenge, aptamers have been applied as the receptors of FET biosensors, utilizing their ability to recognize small molecules and conformational changeability.…”