Limits...
Effect of substrate (ZnO) morphology on enzyme immobilization and its catalytic activity.

Zhang Y, Wu H, Huang X, Zhang J, Guo S - Nanoscale Res Lett (2011)

Bottom Line: The control on the morphology of ZnO nanocrystals was achieved by varying the ratio of CH3OH to H2O, which were used as solvents in the hydrothermal reaction system.The surface of as-prepared ZnO nanoparticles was functionalized with amino groups using 3-aminopropyltriethoxysilane and tetraethyl orthosilicate, and the amino groups on the surface were identified and calculated by FT-IR and the Kaiser assay.Horseradish peroxidase was immobilized on as-modified ZnO nanostructures with glutaraldehyde as a crosslinker.

View Article: PubMed Central - HTML - PubMed

Affiliation: National Key Laboratory of Micro/Nano Fabrication Technology, Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, Research Institute of Micro/Nano Science and Technology, Shanghai Jiao Tong University, Shanghai 200240, PR China. haixiawu@sjtu.edu.cn.

ABSTRACT
In this study, zinc oxide (ZnO) nanocrystals with different morphologies were synthesized and used as substrates for enzyme immobilization. The effects of morphology of ZnO nanocrystals on enzyme immobilization and their catalytic activities were investigated. The ZnO nanocrystals were prepared through a hydrothermal procedure using tetramethylammonium hydroxide as a mineralizing agent. The control on the morphology of ZnO nanocrystals was achieved by varying the ratio of CH3OH to H2O, which were used as solvents in the hydrothermal reaction system. The surface of as-prepared ZnO nanoparticles was functionalized with amino groups using 3-aminopropyltriethoxysilane and tetraethyl orthosilicate, and the amino groups on the surface were identified and calculated by FT-IR and the Kaiser assay. Horseradish peroxidase was immobilized on as-modified ZnO nanostructures with glutaraldehyde as a crosslinker. The results showed that three-dimensional nanomultipod is more appropriate for the immobilization of enzyme used further in catalytic reaction.

No MeSH data available.


The surface functionality of ZnO nanodisks before and after modification. (a) The TEM images of ZnO modified by TEOS:APTES (1:4 in volume). (b) Zeta-potential curves, and (c) FT-IR spectra of ZnO nanodisks before and after modification.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3211870&req=5

Figure 3: The surface functionality of ZnO nanodisks before and after modification. (a) The TEM images of ZnO modified by TEOS:APTES (1:4 in volume). (b) Zeta-potential curves, and (c) FT-IR spectra of ZnO nanodisks before and after modification.

Mentions: In order to immobilize enzyme, the surface of ZnO nanocrystals were functionalized with amino groups using APTES/TEOS. Figure 3a shows a typical image of coated ZnO nanodiscs, where a thin film with uniform thickness of 2 nm formed on the surface. Comparing the Zeta-potentials of the bare ZnO and the as-modified ZnO nanocrystals (Figure 3b), it can be deduced that the surface electrostatic state of ZnO nanocrystals was changed. The surface groups of the modified ZnO were further characterized by FT-IR spectra. Through comparing the FT-IR spectra before and after modification in Figure 3c, except for a few peaks at 3430, 1630, and 433 cm-1 corresponding to water (moisture) and ZnO nanocrystal, the peaks at 2936.3 and 2872 cm-1 of the C-H stretching vibration [26], and the peaks at 1330 and 1560 cm-1 of the stretching vibration of C-N and bending vibration of N-H can be found. In addition, the strong absorption peaks at 3428.6 and 1633.5 cm-1, assigned to N-H bending vibrations, are overlapped with the bending vibration of the absorbed H2O [27]. These results confirmed the presence of amino groups on the ZnO nanocrystals surface.


Effect of substrate (ZnO) morphology on enzyme immobilization and its catalytic activity.

Zhang Y, Wu H, Huang X, Zhang J, Guo S - Nanoscale Res Lett (2011)

The surface functionality of ZnO nanodisks before and after modification. (a) The TEM images of ZnO modified by TEOS:APTES (1:4 in volume). (b) Zeta-potential curves, and (c) FT-IR spectra of ZnO nanodisks before and after modification.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211870&req=5

Figure 3: The surface functionality of ZnO nanodisks before and after modification. (a) The TEM images of ZnO modified by TEOS:APTES (1:4 in volume). (b) Zeta-potential curves, and (c) FT-IR spectra of ZnO nanodisks before and after modification.
Mentions: In order to immobilize enzyme, the surface of ZnO nanocrystals were functionalized with amino groups using APTES/TEOS. Figure 3a shows a typical image of coated ZnO nanodiscs, where a thin film with uniform thickness of 2 nm formed on the surface. Comparing the Zeta-potentials of the bare ZnO and the as-modified ZnO nanocrystals (Figure 3b), it can be deduced that the surface electrostatic state of ZnO nanocrystals was changed. The surface groups of the modified ZnO were further characterized by FT-IR spectra. Through comparing the FT-IR spectra before and after modification in Figure 3c, except for a few peaks at 3430, 1630, and 433 cm-1 corresponding to water (moisture) and ZnO nanocrystal, the peaks at 2936.3 and 2872 cm-1 of the C-H stretching vibration [26], and the peaks at 1330 and 1560 cm-1 of the stretching vibration of C-N and bending vibration of N-H can be found. In addition, the strong absorption peaks at 3428.6 and 1633.5 cm-1, assigned to N-H bending vibrations, are overlapped with the bending vibration of the absorbed H2O [27]. These results confirmed the presence of amino groups on the ZnO nanocrystals surface.

Bottom Line: The control on the morphology of ZnO nanocrystals was achieved by varying the ratio of CH3OH to H2O, which were used as solvents in the hydrothermal reaction system.The surface of as-prepared ZnO nanoparticles was functionalized with amino groups using 3-aminopropyltriethoxysilane and tetraethyl orthosilicate, and the amino groups on the surface were identified and calculated by FT-IR and the Kaiser assay.Horseradish peroxidase was immobilized on as-modified ZnO nanostructures with glutaraldehyde as a crosslinker.

View Article: PubMed Central - HTML - PubMed

Affiliation: National Key Laboratory of Micro/Nano Fabrication Technology, Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, Research Institute of Micro/Nano Science and Technology, Shanghai Jiao Tong University, Shanghai 200240, PR China. haixiawu@sjtu.edu.cn.

ABSTRACT
In this study, zinc oxide (ZnO) nanocrystals with different morphologies were synthesized and used as substrates for enzyme immobilization. The effects of morphology of ZnO nanocrystals on enzyme immobilization and their catalytic activities were investigated. The ZnO nanocrystals were prepared through a hydrothermal procedure using tetramethylammonium hydroxide as a mineralizing agent. The control on the morphology of ZnO nanocrystals was achieved by varying the ratio of CH3OH to H2O, which were used as solvents in the hydrothermal reaction system. The surface of as-prepared ZnO nanoparticles was functionalized with amino groups using 3-aminopropyltriethoxysilane and tetraethyl orthosilicate, and the amino groups on the surface were identified and calculated by FT-IR and the Kaiser assay. Horseradish peroxidase was immobilized on as-modified ZnO nanostructures with glutaraldehyde as a crosslinker. The results showed that three-dimensional nanomultipod is more appropriate for the immobilization of enzyme used further in catalytic reaction.

No MeSH data available.