Metal-based nanoparticles' potential in Alzheimer's disease diagnosis, therapy and theranostics.

Metal-based nanoparticles are emerging as a versatile platform to overcome critical challenges in the diagnosis and treatment of Alzheimer's disease (AD). This review provides a comprehensive synthesis of recent advances, structured around the three core domains of AD management: diagnostics, therapeutics, and theranostics. We discuss how the unique physicochemical properties of metals and metal oxides enable highly sensitive biosensing of amyloid and tau biomarkers, as well as high-contrast imaging modalities. The review then evaluates strategies for engineering metal-based nanoparticles to bypass the blood-brain barrier and achieve targeted accumulation, alongside their therapeutic roles in drug delivery, photothermal therapy, and modulating protein aggregation. Finally, we assess integrated theranostic systems that combine real-time imaging with targeted intervention. The key conclusion is that platforms based on metal-based nanoparticles, through their multifunctionality, offer a realistic pathway toward minimally invasive early diagnosis and targeted therapy. However, the field's future direction must prioritize rigorous standardization and advanced preclinical validation to translate these promising nanotechnologies from bench to bedside, ultimately advancing precision neurotheranostics for AD.