Fabrication and Characterization of Aluminum-Doped ZnO Nanorods for Biosensor Applications

• Published in: IEEE sensors journal Vol. 25; no. 10; pp. 16648 - 16657
• Main Authors: Chou, Hsin-Yu, Chen, Yu-Wei, Yu, Chang-Tze Ricky, Chen, Jo-Mei Maureen, Chiang, Wei-Hsiang, Singh, Anoop Kumar, Kung, Po-Kai, Chiang, Jung-Lung, Wuu, Dong-Sing
• Format: Journal Article
• Language: English
• Published: New York IEEE 15.05.2025; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aluminum; Aluminum-doped zinc oxide (AZO); biomedical sensor; Biosensors; Electrical properties; Electron beams; extended gate field effect transistor (EGFET); Field effect transistors; Glass substrates; Glucose; Indium tin oxide; Indium tin oxides; Ions; Nanorods; pH sensing; Semiconductor device measurement; Semiconductor devices; Sensitivity; Sensors; Substrates; Zinc oxide; Zinc oxides
• DOI: 10.1109/JSEN.2025.3552595
• ISSN: 1530-437X

In this study, we prepared various aluminum-doped zinc oxide (AZO) surface structures via chemical bath deposition (CBD) for use in biomedical sensors. Indium tin oxide (ITO) conductive films were deposited on glass substrates via electron beam evaporation, and AZO nanorods were subsequently grown on the ITO layer using CBD at a bath temperature of <inline-formula> <tex-math notation="LaTeX">90~^{\circ } </tex-math></inline-formula>C. The AZO/ITO sensor electrode was further optimized through furnace annealing, improving its structural and electrical properties. This nanostructure enhances the ability of biomedical sensor films to adsorb H+ and OH<inline-formula> <tex-math notation="LaTeX">{}^{-} </tex-math></inline-formula> ions by increasing the reactive surface area between the film and the solution under test, thereby improving pH sensitivity. In addition, we used an extended gate field effect transistor (EGFET) module to measure glucose concentrations ranging from 0 to 10 mg/ml, achieving sensitivity values of 55.4 mV/pH and 8.07 mA/mg<inline-formula> <tex-math notation="LaTeX">\cdot </tex-math></inline-formula>ml<inline-formula> <tex-math notation="LaTeX">{}^{-{1}} </tex-math></inline-formula>. These findings have significant implications for the future development of blood glucose monitoring and microenvironmental sensing systems.