ACHE and early-onset autosomal dominant Alzheimer disease: A dual-readout (colorimetric and fluorometric) test for acetylcholinesterase (AChE) has been discovered utilizing gold nanoparticles coated with Rhodamine B. The assay has been used to monitor AChE levels in the cerebral fluid of transgenic mice with Alzheimer’s disease due to its high sensitivity and specificity [44].