Synergistic Functions of Enzymes Bound to Semiconducting Layers.
Synthesis and cooperative functions of hybrid materials composed of enzyme and semiconducting layers are described in this chapter. The hybrids were produced via a simple physical interaction between the components, that is, electrostatic interaction in an aqueous solution. To form interstratifying enzymes in the galleries, solution pH, which is a key parameter to decide surface potential, should be adjusted appropriately. In other words, enzymes should have an opposite charge when compared to that of the layers at an identical pH. Even though the intercalation slightly reduced enzymatic activity as compared to those of the free enzymes, stability under cruel conditions was drastically improved due to screening effect of semiconducting layers from extrinsic stimuli. In addition, photochemical control of redox enzymes sandwiched between semiconducting layers was accomplished. Light irradiation of the hybrids induced band gap excitation of the layers, and holes produced in the valence band activated the enzymes. It was revealed that the semiconducting layers with magnetic elements might be useful to magnetic application (separation) of enzymes as similar to conventional magnetic beads.
Graduate School of Engineering, Nagasaki University, Nagasaki, Japan. Electronic address: kkamada@nagasaki-u.ac.jp.
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K
Kamada
Graduate School of Engineering, Nagasaki University, Nagasaki, Japan.
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Yamada
Graduate School of Engineering, Nagasaki University, Nagasaki, Japan.
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Kamiuchi
Graduate School of Engineering, Nagasaki University, Nagasaki, Japan.
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Tokunaga
Graduate School of Engineering, Nagasaki University, Nagasaki, Japan.
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Ito
Faculty of Agriculture, Saga University, Saga, Japan.
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Soh
D002480:Cellulase / Q000737:chemistry; D003102:Colloids; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D010316:Particle Size; D011188:Potassium / Q000737:chemistry; D012666:Semiconductors; D012996:Solutions; D014025:Titanium / Q000737:chemistry
D003102:Colloids; D004800:Enzymes, Immobilized; D012996:Solutions; C009495:titanium dioxide; D014025:Titanium; D007501:Iron; D006735:Horseradish Peroxidase; D002480:Cellulase; D011188:Potassium
Biorecognition; Intercalation; Layered oxide; Magnetic separation; Photoelectrochemistry; Redox enzyme