Near-infrared fluorescent probes for imaging of amyloid- at different stages in monitoring Alzheimer's disease

As one of the expensive and heavy illnesses, Alzheimer's disease (AD) has plagued mankind for a long time. The deposition of amyloid-beta (A beta) plaques in the brain is AD's main early pathological characteristic, and also a growing body of evidence shows A beta deposition is a good diagnostic for AD. In recent years, near-infrared fluorescence (NIRF) imaging has emerged with a real -time, safe, and low-cost imaging technology as a promising diagnostic tool for early diagnosis. In the process of the development of AD, A beta has gone through the monomer, oligomer to insoluble fiber process. Therefore, it is useful and necessary to develop NIRF probes that can specifically detect A beta at various stages. In this review, we summarized the NIRF probes that specifically recognize the A beta at different stages. We focused on the design strategies, optical properties, brain dynamics characteristics, and discussed the structural characteristics of various types of these probes. We believe that this review will provide some ideas for the design of NIRF probes.