Decarpigny_2021_Colloids.Surf.B.Biointerfaces_200_111606

HYPOTHESIS: Porous silica has been extensively used as suitable carrier for the immobilization of various enzymes. Randomly Methylated beta-Cyclodextrin (RaMebetaCD) has surface active properties and very high solubility in water and could therefore be used as template in the fabrication of silica particles with tunable pore size. EXPERIMENTS: Silica particles were prepared by sol-gel process in alkaline medium with and without use of RaMebetaCD. Lipase Bfrom Candida antarctica (CALB) was either incorporated within the pores of RaMebetaCD-derived support or covalently attached on the surface of CD-free silica particles and its catalytic performance was assayed in the oxidation of 2,5-diformylfuran (DFF) to 2,5-furandicarboxylic acid (FDCA). Enzymatic reactors were characterized by N(2)-adsorption analysis, small angle XRD, TG/DSC experiments, ATR-FTIR spectroscopy, HR-TEM and LSCM, while reaction products were determined based on (1)H NMR spectroscopy combined with HPLC. FINDINGS: Results showed that the use of RaMebetaCD as structure directing agent led to mesoporous silica composed of uniform 8 nm-sized particles with 11 nm-sized mesopores compatible with the dimensions of CALB (3.0 nm x 4.0 nm x 5.0 nm). Incorporation of CALB within the pores of RaMebetaCD-derived silica caused almost a two-fold increase in specific activity after 7 h at 40 degreesC when compared to lipase immobilized on the surface of CD-free silica particles (33.2 micromol g(-1) min(-1)vs. 14.4 micromol g(-1) min(-1)). Moreover, the RaMebetaCD-derived biocatalyst demonstrated enhanced operational stability during the recycling experiments, retaining more than 90% of its initial activity after five 24 h-reaction cycles. These findings open up new avenues for future research on the use of cyclodextrins in the development of enzyme-based nanoreactors.