As therapeutics for Alzheimer's disease (AD) become available, it will become increasingly important to develop accurate and reliable tools for its early diagnosis. A recent paper by Georganopoulou et al. suggests that nanobiotechnology could help to overcome the limitations with the current diagnostic methods. The paper introduces a nanoparticle-based assay using antibodies that are specific for amyloid beta-protein (Abeta) oligomers with sub-femtomolar sensitivity. This assay appears to be more specific for AD than previous ELISA-based work and, if specificity of the assay for Abeta oligomers can be established, the method developed might provide a sensitive, reliable diagnostic tool for AD.