Advances in zinc oxide nanobiosensors for medical diagnostics: morphologies, mechanisms and applications

Zinc oxide (ZnO) nanostructures present remarkable morphological, chemical and electrical properties, including a large surface area, semiconductor behavior and a high isoelectric point, positioning them as ideal for biosensing applications. This review outlines the recent advances (2022-2024) in ZnO-based nanobiosensors for medical applications, based on a selection of peer-reviewed, open-access experimental studies extracted from databases including IEE Xplore, Scopus and ScienceDirect. A variety of ZnO morphologies, including nanoflowers, nanorods, nanosheets and nanoparticles have made possible the development of piezoelectric, electrochemical, optical and field-effect transistor biosensors. Experimental data reveal that ZnO-based nanotechnologies achieve rapid detection of lactate, cancer biomarkers, glucose and infectious disease antigens, demonstrating lower detection limits and enhanced sensitivity. Emerging strategies, such as noble metal decoration and integration into wearable platforms or microfluids, have improved efficiency and clinical applicability. ZnO-based nanostructures therefore serve as a promising basis for the next generation of continuous monitoring and point-of-care systems.