the specific surface area
of the uncoated Zn particles was estimated to be 5.78 m2/g.
This increased to 8.37 m2/g after coating of the particles with
the silica nanowires. As described in the experimental section
and depicted in Figure 5, the covalent immobilization of lipase
was achieved by the following steps (i) silylation of the
hydroxyl group on the nanowires by 3-APTES (ii) transformation
of the aminoalkyl group into Schiff’s base by
glutaraldehyde treatment (iii) covalent attachment of the amine
group of the enzyme to the Schiff’s base. The effectiveness of
the silylation process was evaluated by FTIR analysis and the
covalent immobilization was confirmed by the spectrophotometric
lipase assay.
The representative FTIR spectra of the untreated and aminofunctionalized
silica nanowires are shown in Figure 6A. Prior to