CRANAD 2 is a near-infrared (NIR) Aβ plaque-specific fluorescent probe. CRANAD 2 penetrates the blood brain barrier and has a high affinity for Aβ aggregates with a Kd of 38 nM. Upon interacting with Aβ aggregates, CRANAD 2 exhibits a 70-fold increase in fluorescence intensity accompanied by a 90 nm blue shift from 805 to 715 nm and a large increase in quantum yield. CRANAD 2 has been used to detect Aβ deposits noninvasively in vivo in transgenic Tg2576 mice.