Biological applications of near infrared fluorescence dye probes in monitoring Alzheimer's disease.

Alzheimer's disease (AD) is characterized by progressive decrease in cognitive abilities, language impairment and irreversible memory loss. Amyloid-β (Aβ) and tau deposits are essential as the major factors involved in the pathogenesis of AD. Unfortunately, anti-Alzheimer's disease agents currently available are not potent enough to reverse the cause of the disease. Interestingly, near infrared fluorescence (NIRF) dyes have been marked as promising tools in analytical researches and are often adopted as molecular probes to monitor and diagnose AD, in vitro or in vivo. Compared with other imaging techniques, such as positron emission tomography (PET), magnetic resonance imaging (MRI), and single-photon emission computed tomography (SPECT), NIRF dye probes have been applied in AD pre-clinical trials and have gained rapid benefits, in view of their advantages including real time imaging, biocompatibility, high selectivity and sensitivity, high spatiotemporal resolution, and easy data analysis. This work reviews the developmental design of typical NIRF dye probes in monitoring Aβs and tau species in the brain of AD model mice and patients.