Ibuprofen‐imprinted ultrathin poly[N‐(2‐hydroxypropyl) methacrylamide] films

Abstract

Surface molecularly imprinted (MIP) poly [N-(2-hydroxypropyl) methacrylamide] [poly(HPMA)] films were prepared via interface-mediated reversible addition-fragmentation chain transfer (RAFT) polymerization from 4-cyano-4-(propylsulfanylthiocarbonyl) sulfanyl pentanoic acid immobilized silicon substrate using N-(2-hydroxypropyl) methacrylamide as the functional monomer, N,N 0 -methylene(bis)acrylamide as the crosslinking agent, and ibuprofen as the template molecule. The highly crosslinked MIP layer (12 nm) was homogeneously grafted onto the silicon surface, which favors fast mass transfer and rapid binding kinetics. Binding capacities and adsorption parameters of the MIP poly(HPMA) films were calculated from the root-mean-square roughness data obtained by atomic force microscopy measurements using the Luzinov and Langmuir equations adopted for this study. The target binding assays demonstrate the desirable binding capacity and imprinting efficiency of the MIP poly(HPMA) films. Meanwhile, the computational optimization and energy calculations showed the formation of the self-assembly of monomer and template molecule via noncovalent interactions that leads to a 1:4 molecular complex between ibuprofen and N-(2-hydroxypropyl) methacrylamide. This study provides a versatile approach to the quantitative determination of low-molecular-weight biomolecules on surfaceimprinted polymers.