Abstract: The density functional theory was applied to simulate the self-assembly system of molecularly imprinted polymers specific for α-lipoic acid (ALA-MIPs) with N-isopropyl acrylamide (NIPAM) as a functional monomer at the B3LYP level. At the simulated optimal ALA-to-NIPAM, ALA-MIPs were prepared with ethylene glycol dimethacrylate (EGDMA) as a cross-linker and 2,2’-azodiisobutyronitrile (AIBN) as an initiator by bulk polymerization, and the morphology and structure of ALA-MIPs were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The adsorption capacity was evaluated as well. The computational simulation results indicated that the template and the functional monomer at a molar ratio of 1:2 could form stable structures. There were two kinds of binding sites found in the obtained ALA-MIPs; the corresponding dissociation constants were 6.969 7 × 10-5 and 1.558 5 × 10-5 mol/L, and the maximum adsorption capacities of ALA onto ALA-MIPs were 12.145 and 104.06 mg/g, respectively. Moreover, the ALAMIPs showed a good selectivity for ALA and its analogues compared with the non-imprinted polymers (NIPs).

Key words: density functional theory, antioxidant, molecularly imprinting, lipoic acid