Fig. 1. (a) The possible binding sites of Aβ42 protein (PDB: 5OQV); (b) binding site C of Aβ42 (PDB: 5OQV); (c) the design strategy of probe ICTAD-1; (d) the binding model of probe ICTAD-1 with Aβ42 protein (PDB: 5OQV), the red dashed lines note hydrogen bonds; (e) the synthetic route for probe ICTAD-1; (f) the structures of compounds ICTAD-2, ICTAD-3, and ICTAD-4.