New non-covalent functionalized phenyl-methyl-silica for biomolecules immobilization: Experimental and theoretical insights of interactions

A new strategy for functionalization of porous silica with phenyl-methyl groups is developed and demonstrated in this work. Bare silica, a hierarchical bimodal porous material, was functionalized with non-hydrolysable allcylsilane (trimethylphenylsilane) by liquid phase grafting, without the use of additional catalyst. The analyses carried out by FFIR, zeta potential and Si-29 NMR of modified material indicating that the silane is efficiently and stably adsorbed on silica surface. Computational simulations showing the interaction between silane and silica is by formation of bridges between phenyl ring of silane and silanol groups of silica, with interaction energies similar to those found for hydrogen bridges. Additionally, this modification generates a change on hydrophobicity of silica (11% more hydrophobic than bare silica) that allows the success immobilization of lipase from Thermomyces lanuginosus, used as probe biomolecule. This biocatalyst exhibits a specific activity of 45.7 IU (50% more than those obtained with bare silica) and a half-life of 89.9 h at 45 degrees C in acetone, which is 5-fold higher than for the biocatalyst prepared with the bare silica. These results could contribute to the preparation of new and efficient materials to be used as supports for biocatalysts, delivery drugs and remediation. (C) 2017 Elsevier Inc. All rights reserved.