Fig. 2. The synthesis of single-chain polymer nanoparticles (SCPNs) ‘wrapping agents’. (i) Post-polymerisation functionalisation of P1 with imidazole (4-imidazolecarboxaldehyde, 0.1 M AcOH/NH₄OAc, pH 4.5, 18 h) to form the imidazole-decorated polymer P1-Imi₁₅. (ii) Intramolecular crosslinking (terephthalaldehyde, 0.1 M AcOH/NH₄OAc, pH 4.5, 18 h) to afford the ‘wrapping agent’ P1-Imi₁₅-SCPN.