GRANAD-2 is a near-infrared Aβ plaque-specific fluorescent probe penetrating the blood brain barrier and label senile plaques specifically in vivo. Upon interacting with Aβ aggregates, CRANAD-2 displays 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.