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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.


TEM images of amino group-functionalized ZnO nanocrystals. (a) Nanospheres and (b) nanomultipods using TEOS and APTES with the ratio of 1:4 in volume.
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Figure 5: TEM images of amino group-functionalized ZnO nanocrystals. (a) Nanospheres and (b) nanomultipods using TEOS and APTES with the ratio of 1:4 in volume.

Mentions: The aforementioned procedure was also performed on the surface modifications of ZnO nanospheres and nanomultipods with TEOS to APTES ratio of 1:4. Figure 5 depicts the TEM images of the nanosphere and nanomultipod after the modification. Similar to the nanodisks, there are thin coating layers formed both on nanospheres and nanomultipods. The amounts of amino groups on the surfaces of ZnO nanospheres and nanomultipods modified with TEOS to APTES ratio of 1:4 were also measured, which are 0.127 and 0.044 mmol/g, respectively. The specific surface areas of ZnO nanospheres, nanodisks, and nanomultipods are 33.59, 11.99, and 11.85 m2/g, respectively, which were measured using Brunauer-Emmett-Teller (BET) method. Thus, considering the surface areas of different morphologies, the surface densities of amino groups on ZnO nanospheres, nanodisks, and nanomultipods were calculated, which are determined to be 3.78, 5.94, and 3.71 μmol/m2, respectively.


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)

TEM images of amino group-functionalized ZnO nanocrystals. (a) Nanospheres and (b) nanomultipods using TEOS and APTES with the ratio of 1:4 in volume.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 5: TEM images of amino group-functionalized ZnO nanocrystals. (a) Nanospheres and (b) nanomultipods using TEOS and APTES with the ratio of 1:4 in volume.
Mentions: The aforementioned procedure was also performed on the surface modifications of ZnO nanospheres and nanomultipods with TEOS to APTES ratio of 1:4. Figure 5 depicts the TEM images of the nanosphere and nanomultipod after the modification. Similar to the nanodisks, there are thin coating layers formed both on nanospheres and nanomultipods. The amounts of amino groups on the surfaces of ZnO nanospheres and nanomultipods modified with TEOS to APTES ratio of 1:4 were also measured, which are 0.127 and 0.044 mmol/g, respectively. The specific surface areas of ZnO nanospheres, nanodisks, and nanomultipods are 33.59, 11.99, and 11.85 m2/g, respectively, which were measured using Brunauer-Emmett-Teller (BET) method. Thus, considering the surface areas of different morphologies, the surface densities of amino groups on ZnO nanospheres, nanodisks, and nanomultipods were calculated, which are determined to be 3.78, 5.94, and 3.71 μmol/m2, respectively.

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.