We report a fluorinated and iodinated radiotracer as a probe for PET/SPECT to detect of β- amyloid (Aβ) plaques in the brain of patients with Alzheimer's disease (AD). We successfully designed and synthesized the fluorinated and iodinated aurone derivative (3) and its radiolabels ([125I] 3 and [18F] 3). In binding experiments in vitro, 3 showed high affinity for Aβ aggregates (Ki= 6.81 nM). In brain sections of AD model mice, 3 intensely stained Aβ ...