Electrospun-Aligned Gd-Doped In₂O₃ Nanofiber Field-Effect Transistors for Artificial DNA Detection

In view of the time-consuming and laborious problem of detecting biological genetic information by conventional methods, it is important to study high-performance deoxyribonucleic acid (DNA) biosensors. In this report, an aligned Gd-doped In2O3 nanofiber favoring carrier transport was prepared by electrospinning. When the Gd doping concentration is 0.5 mol %, the aligned In2O3 nanofiber field-effect transistors (FETs) exhibit an excellent mobility (μ = 8.7 cm2/Vs), suitable threshold voltage (VTH = 0.3 V), large on/off current ratio (Ion/Ioff = 4.1 × 107), and outstanding stability. The FET biosensor based on one-dimensional nanofibers has the advantages of simple structure, fast response, high sensitivity, and extraordinary potential for biosensor applications, where the current variation is quite pronounced at concentrations as low as 10 nM DNA immobilized in the active layer of the aligned In1.995Gd0.005O3 nanofiber FET, and this phenomenon becomes more pronounced as the concentration of immobilized DNA increases. The sensing mechanism of the current variation is mainly attributed to the oxidation of guanine nucleotides in the DNA molecular chain. The aligned Gd-doped In2O3 nanofiber FETs exhibit high sensitivity to DNA at room temperature, which provides a solution for the development of novel DNA biosensors.