Supports activated with glutaraldehyde or the treatment of the adsorbed enzymes with glutaraldehyde produces a covalent attachment of the enzyme onto the support with glutaraldehyde as a spacer Mizoribine molecular weight arm, conferring stability to covalently bound enzymes . A detailed view
of the surface morphology and thickness has been obtained using the scanning electron microscope (SEM). The porous layer is 3,000 ± 60 nm thick shown in Figure 2a, with interconnecting cylindrical pores ranging in diameter from 30 to 50 nm can be seen in Figure 2b. The pore size distribution is relatively uniform and the columnar walls are thin. Figure 1 Schematic diagram illustrating the general process from porous silicon functionalization to enzyme coupling. (a) Functionalization of oxidized porous support with ADPES. (b) Attachment of aldehyde group using glutaraldehyde. (c) Covalent attachment of peroxidase to the support through the formation of peptide bond between the aldehyde group and amino acids of the enzyme. Figure 2 SEM observation of porous silicon structure fabricated, (a) cross section, (b) sample surface. Reflective interferometric Fourier transform spectroscopy Fourier transform are widely involved in spectroscopy in all research areas that require high accuracy, sensitivity, and resolution [29–31]. It should be noted that the nanostructure
is designed to allow proper infiltration of the peroxidase enzyme (approximate size of 40 KDa), characterized by an Selleckchem 4SC-202 average diameter of 60 to 80 Å, considering
a globular conformation The functionalization of each Fosbretabulin compound was monitored through shift in reflectance peak. It is expected that the chemical modification of the porous nanostructure (as outlined in Figure 3) will result in an increase of the optical thickness (i.e., red shift of second) due to the increase in the average refractive index Bacterial neuraminidase upon attachment of different species to the pore walls. Figure 3 Shift in optical thickness (2nd) of the porous silicon structure after functionalization. The increase of the refractive index after the incubation in APDES and GTA results in a red shift in the reflectance peak, and hence, the corresponding change in optical thickness is observed. FTIR studies Figure 4 shows a FTIR spectrum measured after oxidation step and after immobilization. The reference spectrum of oxidized porous silicon support shows two bands corresponding to the characteristic asymmetric stretching mode of Si-O at 1,050 to 1,100 cm-1 and the Si-OH bond at 825 cm-1 . The spectra of immobilized support show a sharp band of silanol at about 3,730 cm-1 and a band at 3,350 cm-1 correspond to the asymmetric stretching modes of -NH2 groups. . Functionalization with ADPES resulted in a band related to Si-O-Si at 1,034 cm-1, which confirms that the siloxane bonding between ADPES and oxidized support has taken place .