The drastic loss of cholinergic projection neurons in the basal forebrain is a hallmark of Alzheimer’s disease (AD), and drugs most frequently applied for the treatment of dementia include inhibitors of the acetylcholine-degrading enzyme acetylcholinesterase (AChE). This protein is known to act as a ligand of β-amyloid (Aβ) in senile plaques, a further neuropathological sign of AD. Recently, we have shown that the fluorescent, heterodimeric AChE inhibitor PE154 allows for the histochemical staining of cortical Aβ plaques in triple-transgenic (TTG) mice with age-dependent β-amyloidosis and tau hyperphosphorylation, an established animal model for aspects of AD. In the present study, we have primarily demonstrated the targeting of Aβ-immunopositive plaques with PE154 in vivo for 4 h up to 1 week after injection into the hippocampi of 13–20-month-old TTG mice. Numerous plaques, double-stained for PE154 and Aβ-immunoreactivity, were revealed by confocal laser-scanning microscopy. Additionally, PE154 targeted hippocampal Aβ deposits in aged TTG mice after injection of carboxylated polyglycidylmethacrylate nanoparticles delivering the fluorescent marker in vivo. Furthermore, biodegradable core-shell polystyrene/polybutylcyanoacrylate nanoparticles were found to be suitable, alternative vehicles for PE154 as a useful in vivo label of Aβ. Moreover, we were able to demonstrate that PE154 targeted Aβ, but neither phospho-tau nor reactive astrocytes surrounding the plaques. In conclusion, nanoparticles appear as versatile carriers of AChE inhibitors and other promising drugs for the treatment of AD.