Nanotechnology can revolutionize the diagnosis of Alzheimer's disease by enabling the detection of biomarkers at very early stages. For instance, nanoparticles can be engineered to target amyloid-beta plaques and tau tangles, which are the hallmarks of Alzheimer's. These nanoparticles can be coated with specific antibodies that bind to these biomarkers, making them visible under imaging techniques like MRI and PET scans. This enables clinicians to diagnose the disease much earlier than traditional methods.