Alzheimer's disease (AD) is a typical neurodegenerative disease. β -amyloid (A β) plaque is the most prominent pathological biomarker associated with the progression of AD. Conventional A β probes, including commercial probe ThT, usually suffer from tedious washing procedures. Herein, novel AIE-active A β probes with excellent water solubility, named DE-V1-PYC3 and DE-V1-PYOH, were developed for the detection and image of A β without tedious washing procedures. Compared with commercial probe ThT, the AIE-active A β probes exhibited better sensitivity and affinity to A β aggregates. Moreover, for ThT, the washing procedures are essential to obtain high signal-to-noise ratio (SNR) images of A β plaques in AD brain tissue slices. DE-V1-PYC3 and DE-V1-PYOH can label A β plaques in AD brain tissue slices with high SNR even without tedious washing procedures. [ABSTRACT FROM AUTHOR]