Application of nanomaterials in the detection and therapeutic drug monitoring of Hepatitis B virus.

Hepatitis B virus (HBV) infection remains a major global health challenge, requiring accurate diagnostic tools and precise therapeutic drug monitoring (TDM) to guide antiviral treatment and prevent disease progression. Conventional laboratory‑based assays, while reliable, are often limited by long turnaround times, high operational costs, and the need for specialized infrastructure. Recent advances in nanomaterials have transformed the landscape of HBV diagnostics and TDM by enabling highly sensitive, rapid, and cost‑effective analytical platforms. Nanostructures such as gold nanoparticles, quantum dots, carbon nanotubes, graphene derivatives, and magnetic nanomaterials offer unique physicochemical properties including large surface area, tunable optical signatures, and enhanced biorecognition capabilities that significantly improve assay performance. These materials have been integrated into diverse sensing modalities, including electrochemical biosensors, fluorescence‑based assays, plasmonic platforms, and point‑of‑care devices, achieving ultralow detection limits for HBV DNA, HBsAg, and other clinically relevant biomarkers. In therapeutic monitoring, nanomaterial‑enabled sensors facilitate real‑time quantification of antiviral drugs such as tenofovir and entecavir, supporting personalized treatment strategies and improving adherence assessment. Despite promising advancements, challenges remain regarding clinical translation, standardization, biocompatibility, and large‑scale manufacturing. This narrative review summarizes current nanomaterial‑based approaches for HBV detection and TDM, highlights emerging technologies, and discusses future directions for integrating nanodiagnostics into routine clinical practice to enhance HBV management and global disease control.