Developing an effective means for the real-time probing of amyloid β (Aβ) that is closely implicated in Alzheimer's disease (AD) could help better understand and monitor the disease. Here we describe an economic approach based on the simple composition of a natural product, resveratrol (Res), with graphene oxide (GO) for the rapid, fluorogenic recognition of Aβ. The Res@GO composite has proved specific for Aβ over a range of proteins and ions, and could sensitively capture both Aβ monomers and fibers in a physiological buffer solution within only 3 min. The composite can also fluorescently image amyloid deposits in a mouse brain section within 30 min. This new protocol is much cheaper and more timesaving than the conventional immunofluorescence staining technique employed clinically, providing an economic tool for the concise detection of AD.