Protein function and activity are determined by both their assembly and secondary structure. Abnormalities related to either protein aggregation or secondary structure can lead to neurodegenerative diseases. In a new study, an international research team reveals how fluoride nanoparticles, materials used in in vivo imaging, affect the assembly and structure of the amyloid β protein. Their results present a step towards better treatment and prevention of neurologic disorders like Alzheimer's disease.