Artificial DNA nanostructure detection using solution-processed In-Ga-Zn-O thin-film transistors

TLDR

The study develops a method for detecting artificial DNA using solution‑processed In‑Ga‑Zn‑O thin‑film transistors. The detection relies on IGZO TFTs with a field‑effect mobility of 0.07 cm²/Vs and an on‑current of ~2.68 µA, onto which double‑crossover DNA is immobilized via a dry‑wet process. Immobilization of DX DNA caused μFET to drop to 0.02 cm²/Vs, Ion to 0.247 µA, and a positive threshold‑voltage shift, due to electrostatic interactions from the DNA’s negatively charged phosphate backbone.

Abstract

A method for detecting artificial DNA using solution-processed In-Ga-Zn-O (IGZO) thin-film transistors (TFTs) was developed. The IGZO TFT had a field-effect mobility (μFET) of 0.07 cm2/Vs and an on-current (Ion) value of about 2.68 μA. A dry-wet method was employed to immobilize double-crossover (DX) DNA onto the IGZO surface. After DX DNA immobilization, significant decreases in μFET (0.02 cm2/Vs) and Ion (0.247 μA) and a positive shift of threshold voltage were observed. These results were attributed to the negatively charged phosphate groups on the DNA backbone, which generated electrostatic interactions in the TFT device.