BACE1 and Alzheimer disease: The two molecules are connected by a BACE1 substrate (EVNL‐DAEFRHDSGYK).[28, 29] Finally, the nanoprobe surface was functionalized with KLVFFAED peptide (Ab peptide) as a receptor for advanced glycation end products (RAGE)‐mediated blood‐brain barrier (BBB) penetration and active Aβ plaques targeting,[30, 31] ultimately yielding a smart responsive MR nanoprobe (Ab‐MZF@DMSA/Gd) for early AD diagnosis (Scheme 1B).