KR20120116711A - Method for photochemical regenerating oxidoreductase cofactor using nanotubular metal oxide-inorganic photosensitizer complex - Google Patents

Abstract

PURPOSE: A photochemical recycling method of oxidoreductase cofactor using nano-tube formed metal oxide-inorganic photo active compound composite is provided to effectively recycle the cofactor by converting photo energy into electrical energy. CONSTITUTION: A photochemical recycling method of oxidoreductase cofactor comprises the following step: manufacturing reduction type oxidoreductase cofactor by irradiating lights on the same. The nano-tube formed metal oxide-inorganic photo active compound composite is manufactured by the following steps: manufacturing a nano-tube formed metal oxide through cathode oxidation process; and coating the nano-tube formed metal oxide with inorganic photo active compound by using SILAR(successive ionic layer adsorption and reaction) process. The inorganic photo active compound is CdS, CdSe, CdTe, PbS, ZnS, InP or GaAs. The metal-oxide is TiO2, SiO2, Fe2O3, IrO2, Co3O4 or WO3. The oxidation oxidoreductase cofactor is NAD+, NADP+, FAD+ or FMN+. The oxidoreductase cofactor reproduction solvent additionally contains a redox mediator.

Description

Method for Photochemical Regenerating Oxidoreductase Cofactor Using Nanotubular Metal Oxide-Inorganic Photosensitizer Complex}

The present invention relates to a photochemical regeneration method of a redox enzyme cofactor using a metal oxide-inorganic photosensitive complex in nanotube form, and more specifically, a redox oxide coenzyme cofactor, a metal oxide in nanotube form- The present invention relates to a photochemical regeneration method of a redox enzyme cofactor which generates a reduced redox enzyme cofactor by irradiating light to a redox enzyme cofactor regeneration solution containing an inorganic photosensitizer complex and a sacrificial electron donor.

Catalytic reactions using enzymes, unlike chemical catalysts, are capable of producing only certain substances without by-products, and thus play an important role in producing industrially necessary fine chemicals. In particular, redox enzymes such as glutamate dehydrogenase (GDH), alcohol dehydrogenase (ADH), lactate dehydrogenase (LDH), and the like, are expensive and precise such as chiral compounds, alchol, aldehyde, and amino acid. It is mainly used to produce chemicals and its use value is very high.

The enzyme consists of a main enzyme (apoenzyme) and coenzyme (coenzyme) consisting of proteins, the coenzyme is divided into cofactors or prosthetic groups depending on whether the metal ion. Coenzyme, as we usually refer to, refers strictly to a cofactor, which temporarily accepts atoms or groups of atoms released from a substrate and delivers them to other materials.

In particular, the cofactor plays a very important role in performing the enzymatic reaction because the cofactor acts as a reducing equivalent in the biocatalytic reaction using the redox enzyme. However, cofactors having two forms of oxidation or reduction cannot always be used for enzymatic reactions when they are converted to another state, so they should always use the same amount as the enzyme substrate. There are many economic difficulties to use.

Therefore, researches for regenerating and reusing cofactors have been conducted. Representative methods include biochemical and electrochemical methods using a second enzyme. Among them, the biochemical method using the second enzyme has a number of problems such as the formation of by-products according to the reaction of the second enzyme or a decrease in the overall reaction rate due to low thermodynamic equilibrium caused by competition between substrates. Thus, electrochemical regeneration has been considered as an attractive alternative to biochemical methods using conventional second enzymes (F. Hollmann et al., Biocatal. Biotransform., 22, 63, 2004 ). However, electrochemical regeneration method had in ^{NAD (P) + NAD (P} ) reduced the disadvantage in the voltage condition is thermodynamically favored due to slow the electron transfer rate between the electrode and the NAD (P) ⁺ poor reproduction efficiency to H in. To solve this problem, a method of transferring electrons between an electrode and NAD (P) ⁺ using a homogeneous redox mediator has been developed (H. Jaegfeldt et al., Anal. Chem., 53: 1979). , 1981; J. Wang et al., Anal. Chim. Acta, 284: 385, 1993; J. Wang et al., Anal. Chim. Acta, 360: 171, 1998).

Specifically, methyl viologen has been used for indirect electrochemical regeneration with Flavoenzyme (Ferredoxin reductase (FDR) or Lipoamide Dehydrogenase (LipDH)) as an electron transfer medium for NAD (P) H ( Dicosimo et al., J Org Chem, 46: 4622, 1981), electron transfer of ruthenium (II) complex (hexamethylbenzene-2,2′-bipyridinechloro) ruthenium (II) to reduction of ketones with alcohols (Ogo S et al., Organometallics, 21: 2964, 2002; Yaw Kai Yan et al., J Biol Inorg Chem, 11: 483, 2006) and the rhodium (III) complex (Penta) Methylcyclopentadienyl-2,2'-bipyridinechloro) rhodium (III): mediator for electron transfer of [Cp * Rh (bpy) H ₂ O] ²⁺ (hereinafter M _ox ) to NAD (P) ⁺ (R. Ruppert et al., Tetrahedron Lett., 28: 6583, 1987; F. Hollmann, et al., Angew. Chem., 113: 190, 2001; Angew. Chem. Int. Ed., 40: 169, 2001; K. Vuorilehto et al., Bioelectrochemistry, 65: 1, 2004), The rhodium III complex has been used for the regeneration of FADH ₂ (F. Hollmann et. al ., Journal of Molecular Catalysis B: Enzymatic , 19-20: 167, 2003).

The rhodium III complex M _ox in the electron transport medium is converted into M _red2 , an active reducing _agent , through electrochemical / chemical processes and is involved in the regeneration of NADH. M _ox accepts two electrons and _becomes the state of M _red1 by an electrochemical change (E-step). The M _red1 is then converted to M _red2 through a chemical process by taking one proton in solution without changing the total amount of electrons (C-step). The active reductant M _red2 provides two electrons and one proton to NAD (P) ⁺ to convert to NAD (P) H, where it returns to its initial state, M _ox .

However, the electrochemical regeneration method has a disadvantage in that the productivity is limited since the yield is essentially dependent on the surface area of the electrode. The use of a large surface area electrode can achieve such a high reaction rate and productivity, but there is a difficulty in mass production due to an increase in the infrastructure cost.

On the other hand, photochemical cofactor regeneration using light is already used in the name of photosynthesis in nature. Natural photosynthetic organisms such as plants regenerate reducing power using solar energy and store them in the form of cofactors, and carbohydrates necessary for survival through the Calvin cycle in the absence of light Used to synthesize various chemicals.

Due to the nature of the photochemical regeneration method that obtains energy from sunlight through the photosensitizer, the photoresist must absorb as much energy as possible from the sun. TiO ₂ , ZrO ₂ , SrTiO ₃ , Ta ₂ O ₅ Metal oxide photosensitive agents such as these were mainly suitable for absorbing light in the ultraviolet region. Given the fact that the energy in the ultraviolet region corresponds to 4% of the total solar energy, the development of new photosensitizers that absorb 46% of the visible region is essential.

On the other hand, nanoparticles have the advantage of being able to easily adjust the optical properties by controlling the particle size, synthesize at a relatively low value at low temperature, and has a large surface area compared to the volume. Due to these advantages, nanoparticles are used in various fields such as multicolor optical coding, biological imaging, and optoelectronic devices, and among them, CdS, CdSe, and CdTe nanoparticles have been widely used in solar cells that are in the spotlight recently. The high absorption coefficients of these nanoparticles help the solar cells absorb large amounts of light, and their excellent light stability enables long-term stable use of the solar cells.

On the other hand, inorganic nanotubes have several properties that are advantageous for application in the field of optoelectronics and nanohydrodynamics. Nanotubes can be adjusted to have an inner diameter of 1-100 nm, structurally robust, and easy to functionalize the interior and exterior surfaces. It is also possible to adjust the composition and aspect ratio. In particular, the ionic and electrostatic atmospheres can be controlled in time and space, creating a femto-liter volume for biological and chemical analysis. Single nanotube transistors can be used to detect small amounts of charged species or single biological molecules. Similar to field effect transistors in metal oxide semiconductors, nanofluidic transistors can form the basic units for building integrated nanofluidic circuits that can precisely tune a single molecule. (CNR Rao et al., Dalton Trans., 1, 2003; J. Goldberger et al., Acc. Chem. Res., 39: 239, 2006; Korea Institute of Energy Research, 'Metal Oxide Nanotubes' )

The present inventors have developed a method for efficiently regenerating a redox enzyme cofactor, by using a spherical inorganic photosensitive-metal oxide complex to regenerate a cofactor (Korean Patent No. 10-2010-0047832). Ho), we are working on a more efficient method of regeneration of redox enzyme cofactors.

Accordingly, the present inventors have made intensive efforts to develop a method for regenerating oxidative enzyme enzyme cofactors with high efficiency by using a photochemical method. As a result, the cofactors using the metal oxide-inorganic photosensitizer complex in the nanotube form In the case of regeneration, it has been confirmed that the redox enzyme cofactor can be photochemically recovered efficiently, thereby completing the present invention.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for efficiently regenerating a redox enzyme cofactor using sunlight as an energy source.

Another object of the present invention is to provide a composition for regeneration of a redox enzyme cofactor.

Still another object of the present invention is to provide a method for preparing a compound using the redox enzyme cofactor regeneration composition.

In order to achieve the above object, the present invention is reduced by irradiating a redox redox enzyme cofactor regeneration solution containing an oxidative redox enzyme cofactor, a metal oxide-inorganic photosensitizer complex in the form of nanotubes and a sacrificial electron donor It provides a photochemical regeneration method of a redox enzyme cofactor, characterized in that to produce a type redox enzyme cofactor.

The present invention also provides a composition for regeneration of a redox enzyme cofactor containing an oxidative redox enzyme cofactor, a metal oxide-inorganic photosensitive agent complex in nanotube form, and a sacrificial electron donor.

The present invention also comprises the steps of (a) preparing a metal oxide in the form of nanotubes through anodization; And (b) coating an inorganic photosensitizer on the nanotube-type metal oxide using a successive ionic layer adsorption and reaction (SILAR) process. Provide a method.

The present invention also provides a method for preparing a compound through a redox reaction of a substrate using a redox enzyme and a cofactor thereof, wherein the cofactor of the redox enzyme is regenerated using the composition for regenerating the redox enzyme cofactor. It provides a method for producing a compound, characterized in that to perform a redox reaction using the regenerated cofactor.

Regeneration method of the redox enzyme cofactor according to the present invention can convert the light energy in the visible light region to electrical energy using a metal oxide-inorganic photosensitizer complex in the nanotube form, it is possible to efficiently regenerate the cofactor, At the same time, by linking the redox enzyme reaction to the cofactor regeneration, it is possible to finally produce a fine chemical from the light energy, which can be useful for carrying out various biocatalytic reactions using the redox enzyme.

1 is a SEM image and photoenzyme of TiO ₂ -CdS nanotube (a) prepared by anodizing for 1 hour at 60V and TiO ₂ -CdS nanotube (b) prepared by anodizing for 12 hours at 30V Experimental apparatus (c) for the reaction is shown.
FIG. 2 shows SEM images of TiO ₂ nanotubes (a, b) before CdS coating and TiO ₂ nanotubes (c, d) after CdS coating.
FIG. 3 shows XRD patterns of TiO ₂ nanotubes (gray solid line) before CdS coating and TiO ₂ nanotubes (black solid line) after CdS coating.
FIG. 4 shows the absorption spectra of TiO ₂ nanotubes (solid gray line) before CdS coating and TiO ₂ nanotubes (solid black line) after CdS coating.
5 shows the absorption spectra of TiO ₂ -CdS nanotubes according to the number of CdS coatings.
6 is a graph showing the component ratios of Cd and S of TiO ₂ -CdS nanotubes according to the number of CdS coatings.
FIG. 7 shows NADH regeneration scheme (a) and spectra (b) measured to determine the concentrations of NAD ⁺ and NADH during the NADH regeneration reaction.
8 is a graph showing the regeneration rate of NADH of TiO ₂ -CdS nanotubes having different dimensions.
9 is a graph showing the regeneration rate of NADH by TiO ₂ -CdS nanotubes and Al ₂ O ₃ -CdS nanotubes according to the number of CdS coating.
10 shows an SEM image of TiO ₂ -CdS prepared by performing the SILAR process seven times.
Figure 11 shows a schematic view of the TiO ₂ -CdS nanotube energy level diagram (energy-level diagram) and TiO ₂ -CdS production of play and L-glutamte of the cofactor by the nanotubes.
12 shows SEM images of Al ₂ O ₃ nanotubes (a to c) before CdS coating and Al ₂ O ₃ nanotubes (d to g) after CdS coating.
FIG. 13 shows an energy-level diagram of TiO ₂ -CdS nanotubes and Al ₂ O ₃ -CdS nanotubes.
FIG. 14 shows SEM images of TiO ₂ nanotubes annealed at room temperature (a), 300 ° C. (b) and 450 ° C. (c).
FIG. 15 shows XRD patterns of TiO ₂ nanotubes annealed at room temperature, 150 ° C., 300 ° C. and 450 ° C. FIG.
FIG. 16 shows Raman spectra of TiO ₂ nanotubes annealed at room temperature, 150 ° C., 300 ° C. and 450 ° C. FIG.
FIG. 17 is a graph showing the regeneration rate of NADH of TiO ₂ -CdS nanotubes annealed at room temperature, 150 ° C., 300 ° C. and 450 ° C. FIG.
FIG. 18 is a graph showing the regeneration rate of NAHD of TiO ₂ -CdS nanotubes annealed at room temperature, 300 ° C. and 450 ° C. according to the number of CdS coatings.
19 shows an SEM image of a nanoparticulate TiO ₂ film.
20 shows the XRD pattern (a) and Raman spectra (b) of the nanoparticulate TiO ₂ film.
21 is a nano-tube-type TiO ₂ (TiO ₂ -CdS nanotubes) TiO ₂ films and nanoparticles NADH refresh rates (a) and the nano-tube-type TiO ₂ of a castle TiO ₂ film (TiO ₂ -CdS nanotubes) TiO ₂ films and nanoparticles A schematic diagram (b) of NADH photoregeneration through a stiff TiO ₂ film is shown.
22 is a graph showing the concentration of L-glutamate produced using TiO ₂ -CdS nanotubes.

In one aspect, the present invention provides a reduction type redox by irradiating a redox redox enzyme cofactor regeneration solution containing an oxidative redox enzyme cofactor, a nanooxide-type metal oxide-inorganic photosensitive complex, and a sacrificial electron donor The present invention relates to a photochemical regeneration method of a redox enzyme cofactor, characterized by generating an enzyme cofactor.

In the present invention, the nanotube-type metal oxide-inorganic photosensitive composite is prepared by producing an nanotube-type metal oxide by anodizing, and then, using a successive ionic layer adsorption and reaction (SILAR) process. The inorganic oxide sensitizer may be coated on the metal oxide of the metal oxide, and preferably, four times of successive ionic layer adsorption and reaction (SILAR) processes may be performed to prepare the metal oxide-inorganic photosensitive agent in the form of nanotubes. have.

In one aspect, the present invention, in order to prepare a metal oxide-inorganic photosensitive composite in the form of nanotubes, TiO ₂ nanotubes are prepared by anodizing, and then using a successive ionic layer adsorption and reaction (SILAR) process. CdS nanoparticles were coated. The CdS-coated TiO ₂ nanotubes (TiO ₂ -CdS nanotubes) were confirmed by SEM, and the average diameter and length of TiO ₂ nanotubes and the surface area of TiO ₂ measured per cm ² of the TiO ₂ substrate were 60V. Were 94.9 ± 11.1 nm, 13.8 ± 1.1 μm and 581 cm ² for anodized samples for 1 h at, and 63.4 ± 5.8 nm and 7.7 ± 0.3 μm for anodized samples for 12 h at 30 V respectively. And 485 cm ² .

In the present invention, the inorganic photosensitizer may be selected from the group consisting of CdS, CdSe, CdTe, PbS, ZnS, InP, and GaAs, and the present invention is not limited thereto. Any inorganic particles absorbing visible light may be used. Do.

In addition, the metal oxide in the present invention may be selected from the group consisting of TiO ₂ , SiO ₂ , Fe ₂ O ₃ , IrO ₂ , Co ₃ O ₄ and WO ₃ , preferably TiO ₂ , the oxidation The type redox enzyme cofactor may be selected from the group consisting of NAD ⁺ , NADP ⁺ , FAD ⁺ and FMN ⁺ , and preferably NAD ⁺ .

The redox coenzyme regeneration solution may further contain a redox mediator, and the presence of the redox mediator may be used to regenerate the cofactor in a form active in the enzymatic reaction and to speed up the regeneration of the cofactor. In this regard, the presence of the redox mediator does not limit the scope of the present invention because photochemical regeneration of direct cofactors is possible through the photosensitization even without the presence of the redox mediator.

In the present invention, the redox mediator may be methylbiologen, ruthenium II complex, and rhodium III complex. For example, the ruthenium II complex may be (hexamethylbenzene-2,2′-bipyridinechloro) ruthenium (II) yl. And the rhodium III complex may be (pentamethylcyclopentadienyl-2,2'-bipyridinechloro) rhodium (III).

In another aspect, the present invention provides for the formation and growth of CdS nanoparticles on TiO ₂ nanotubes during a SILAR process by monitoring changes in SEM images, X-ray diffraction (XRD) patterns, absorption spectra and elemental composition. As a result, it was confirmed that before the CdS coating, the clean TiO ₂ nanotubes were well aligned with each other and perpendicular to the underlying Ti substrate, and the TiO ₂ nanotubes after the CdS coating were roughened by the formation of CdS nanoparticles. ) Increased.

In addition, it was confirmed that the TiO ₂ nanotubes, which showed little absorbance in the visible region, absorbed the visible region by the formation of CdS nanoparticles after CdS coating, and absorbed spectra according to the number of SILAR process cycles for CdS coating. As a result, it was confirmed that red-shift from UV to visible region after CdS coating, and measured relative components of CdS-coated TiO ₂ nanotubes according to the number of SILAR process cycles for CdS coating. As a result, it was confirmed that the amount of Cd and S gradually increased after CdS coating.

In another embodiment, the optical bandgap of the TiO ₂ -CdS nanotube film prepared above was measured. As a result, the optical bandgap of the TiO ₂ -CdS nanotube film decreased as the CdS coating process was repeated. This reduction implies a quantum confinement effect, where the actual size of CdS nanoparticles (e.g., CdS has a size of 2.36 nm after 4 cycles of SILAR process) for CdS smaller than 10 nm In the range of effect (Y. Wang et al., Phys. Rev. B, 42: 7253, 1990).

In the present invention, the sacrificial electron donor is a material that provides electrons to fill the electron pores generated by the transfer of electrons excited in the nanotube-type metal oxide-photosensitive composite to the redox mediator. Triethanolamine (TEOA), ethylenediaminetetraacetic acid (EDTA), citric acid, formic acid, ascorbic acid, oxalic acid or water But preferably TEOA or EDTA.

In the present invention, the light may be selected from the group consisting of tungsten-halogen lamp light, xenon lamp light, short wavelength laser light, and sunlight, but is not limited thereto, and any light may be used in the visible light region.

The invention in another aspect, for NADH optical reproducing to test the availability of a CdS the TiO ₂ nanotube film coating for the photochemical NADH regeneration, as a result of measuring the concentration of NAD ⁺ and NADH, the concentration of NAD ⁺ Was decreased over time, whereas the concentration of NADH was increased, comparing the regeneration rate of NADH over time for TiO ₂ nanotubes without CdS and TiO ₂ -CdS nanotubes of different sizes. , TiO ₂ nanotubes without CdS coating hardly regenerated NADH, and in the case of TiO ₂ -CdS nanotubes, the larger pore diameter (94.9nm vs 63.4nm) showed better optical regeneration rate. Confirmation (50.3% vs 5.35% for 2 hours). This means that dispersion of reactive species is an important factor for optimizing the optical regeneration system.

The present invention In another embodiment, the result of comparing the NADH refresh rate based on the number of coating of CdS, the TiO ₂ -CdS prepared by four cycles of SILAR process, regardless of the size of the TiO ₂ nanotubes nanotube (4 × TiO ₂ -CdS) film was confirmed to have the best NADH regeneration rate. These results indicate that as the number of CdS coatings increases, a large amount of light can be absorbed, while the effectiveness of channel blocking and charge separation of TiO ₂ nanotubes due to the formation of large CdS agglomerates decreases. It was assumed that it was because of losing.

In another aspect, the present invention provides a CdS coated Al ₂ O ₃ nanotubes (Al ₂ O ₃ −) to confirm that efficient charge separation in TiO ₂ -CdS nanotubes can improve the efficiency of NADH photoregeneration. CdS nanotubes) and NADH photoregeneration efficiency of TiO ₂ -CdS nanotubes were compared. First, Al ₂ O ₃ -CdS nanotubes prepared by the Al ₂ O ₃ nanotubes was confirmed that an CdS nanoparticles on the entire surface coating, nano-Al ₂ O ₃ with an average diameter and length of the pores of the tube, respectively 211nm and 60μm It was confirmed that. In addition, as a result of measuring the NADH regeneration rate of TiO ₂ -CdS nanotubes and Al ₂ O ₃ -CdS nanotubes, the Al ₂ O ₃ -CdS nanotube film has a larger dimension (average 211 nm pore diameter than TiO ₂ -CdS nanotubes). and despite the length of 60μm) and a larger surface area (1cm ² has a 1131cm ²⁾ per substrate, Al ₂ O ₃ -CdS nanotube film exhibited a lower refresh rate.

This result is due to high levels of recombination (charge recombination), TiO ₂ -CdS nanotubes case of the film, to the TiO ₂ from the CdS electron injection gajigi a CdS is more negative (negative) electric band level than the TiO ₂ Due to its thermodynamic advantage, it inhibits electron-hole recombination that occurs favorably in nanoscale semiconductor particles, while electrons excited in Al ₂ O ₃ -CdS nanotube films have higher hole levels than TiO ₂ -CdS nanotube films. Can be recombined with, resulting in a lower efficiency of NADH photoregeneration (M means [Cp * Rh (bpy) H ₂ 0] ²⁺ complex).

In another aspect, the present invention is to adjust the crystallinity of the TiO ₂ nanotubes by heat treatment at various temperatures (room temperature, 150 ℃, 300 ℃ and 450 ℃), in order to improve the optical regeneration rate of NADH, Crystallization was observed using multiple analysis tools such as SEM, XRD and Raman analyzer. As a result, the tubular morphology of TiO ₂ nanotubes remained after annealing at high temperature, but the smooth surface was rugged, and the amorphous TiO ₂ nanotubes were annealed at high temperature, followed by an anatase phase. In the Raman spectra, it was confirmed that the intensity of the peak corresponding to anatase TiO ₂ increased with the red shift of the Eg band in the Raman spectra. Annealing at temperatures above 600 ° C. interferes with the tubular structure and causes phase transformation into the rutile phase.

In another embodiment, TiO ₂ nanotubes having different crystallizations were coated with CdS, and then NADH photoregeneration was compared. The higher the crystallinity of TiO _2, the lower the density of defects acting as electron trapping sites, and thus the higher the regeneration efficiency of NADH. As a result, the size of the TiO ₂ nanocrystals increased with annealing temperature up to 300 ° C., while the 4 × TiO ₂ -CdS nanotube film had about 1.5-fold increase in photoregeneration efficiency from 49.9% to 75.2%. This result is due to the increased electron lifetime due to the crystallization of TiO ₂ (S. Nakade et al., J. Phys. Chem. B, 106: 10004, 2002).

However, TiO ₂ nanotubes treated at 450 ° C reduced their efficiency to 54.4%, and recent studies show that larger crystal formation reduces surface area and increases the efficiency of electron lifetimes in the efficiency of cofactor photoregeneration. It has been reported to counterbalance.

According to another aspect of the present invention, after comparing the photoregeneration rate of NADH of TiO ₂ nanotube film according to the number of coating of CdS after annealing at various temperatures, the most NADH regeneration rate was obtained when four CdS coatings were performed at all temperatures. It was confirmed to be excellent.

The present invention manufactured a In another aspect, in order to examine the morphological effects (morphological effect) of the TiO ₂ film having a nanostructure in an optical reproducing efficiency, (particulate TiO ₂ film) TiO ₂ film consisting of nano-particles for comparative experiment Next, the formation of TiO ₂ films composed of nanoparticles was confirmed using SEM, XRD and Raman analyzer.

As a result, TiO ₂ in the nanoparticle film had a size similar to TiO ₂ size (9.3 nm vs 10.4 nm) in a tubular film annealed at 450 ° C., with nanocrystalline anatase phase. (phase) was confirmed.

The invention in another aspect, TiO _2, and nano-tube-type TiO ₂ film consisting of nano-particles is a result of performing the following each NADH regeneration tests coated with CdS compare the efficiency of NADH optical reproducing, nano-tubular TiO ₂ film nano It was confirmed that NADH can be regenerated at least four times more effectively than TiO ₂ composed of particles. These results indicate that the efficient dispersion of reactive species in nanotube films is an important factor for the high efficiency of NADH photoregeneration.

Thus, TiO ₂ -CdS nanotube films are easy to synthesize and have morphology control (JM Macak et al, Angew. Chem. Int. Ed., 44: 7463, 2005; K. Shankar et al., J. Phys. Chem. C, 113: 6327, 2009) Easy and efficient charge separation (PV Kamat, J. Phys. Chem. C, 112: 18737, 2008; W.-T. Sun et al., J. Am. Chem. Soc., 130: 1124, 2008) and the reaction species (reaction species) has the advantage of such a good dispersion through the nanotubes.

In another aspect, the present invention relates to a composition for regeneration of a redox enzyme cofactor containing an oxidative redox enzyme cofactor, a metal oxide-inorganic photosensitizer complex in nanotube form, and a sacrificial electron donor.

In still another aspect, the present invention provides a method for preparing a metal oxide in the form of nanotubes through anodizing; And (b) coating an inorganic photosensitizer on the nanotube-type metal oxide using a successive ionic layer adsorption and reaction (SILAR) process. It is about a method.

The successive ionic layer adsorption and reaction (SILAR) process may be performed 3 to 5 times as needed, and preferably 4 times.

In another aspect, the present invention provides a method for preparing a compound through a redox reaction of a substrate using a redox enzyme and a cofactor thereof, wherein the cofactor of a redox enzyme is prepared using the composition for regenerating the redox enzyme cofactor. It relates to a method for producing a compound, characterized in that for regenerating, and performing a redox reaction using the regenerated cofactor.

In the present invention, artificial photosynthesis was designed to mimic the cofactor regeneration that occurs through the photosynthesis of natural photosynthesis using inorganic photosensitive-metal oxide nanotubes, and to replace the glucose synthesis reaction with the production of compounds by redox enzyme reactions. Artificial photosynthesis' mimics the natural and photosynthetic light and dark reactions, which produce compounds through redox enzyme reactions that regenerate cofactors of redox enzymes and co-factors of redox enzymes regenerated in the light reactions. It refers to a series of cancer reactions.

As used herein, the term 'compound' means a substance synthesized through a redox reaction requiring a cofactor from a substrate.

In the present invention, (a) adding a substrate and a redox enzyme to the redox enzyme cofactor regeneration composition, and then irradiating light to regenerate the redox enzyme cofactor; And (b) obtaining a compound prepared through a redox enzyme reaction using the regenerated cofactor.

In the present invention, the compound may be selected from the group consisting of L-glutamate, Lactate, and alcohol, and preferably L-glutamate.

In the present invention, the substrate may be selected from the group consisting of a-ketoglutarate, aldehyde (Aldehydes) and pyruvate (Pyruvate) as a precursor of the compound, for example, to produce L- glutamate To do this, a-ketoglutarate can be used as the substrate.

The redox enzyme in the present invention may be selected from the group consisting of glutamate dehydrogenase (GDH, glutamate dehydrogenase), alcohol dehydrogenase (ADH, alcohol dehydrogenase) and lactate dehydrogenase (LDH, lactate dehydrogenase), preferably glutamic acid It may be a dehydrogenase.

In yet another aspect, the present invention provides a method for synthesizing L-glutamate using TiO ₂ -CdS nanotubes, wherein the reductive amine reaction catalyzed by GDH (glutamate dehydrogenase) is carried out using NAD ⁺ using TiO ₂ -CdS nanotube films. From photoregeneration of NADH. As a result, L-glutamate was successfully synthesized by combining NADH photoregeneration with a reductive amination reaction catalyzed by a redox enzyme (ie, GDH).

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are only for illustrating the present invention and that the scope of the present invention is not construed as being limited by these embodiments.

TiO ₂ -CdS Nanotube Film Fabrication

TiO ₂ nanotubes were prepared via anodization (JM Macak et al., Angew. Chem. Int. Ed., 44: 7463, 2005; K. Shankar et al., J. Phys. Chem. C, 113 : 6327, 2009).

First, before anodizing, the Ti foil was cut to a size of 10 mm × 40 mm and degreaseed by ultrasonication in acetone and ethanol for 30 minutes. Anodization of Ti was performed by using Ti foil as the working electrode and porous graphite felt as the counter electrode in two electrode arrangements for 1 hour at 60V or 12 hours at 30V.

Anodized TiO ₂ nanotubes were subjected to ultrasonication in a water / ethanol mixture to remove surface debris generated during anodization, and then to the successive ionic layer adsorption and anodized TiO ₂ nanotubes. CdS nanoparticles were coated using a process (DR Baker et al., Adv. Funct. Mater., 19: 805, 2009). One cycle of the SILAR process consisted of 10 min continuous treatment of 0.1 M CdSO ₄ , distilled water, 0.1 M Na ₂ S and distilled water, respectively, and the CdS loading level was controlled by repeating the SILAR process (No. 0-7).

The prepared CdS-coated TiO ₂ nanotubes (TiO ₂ -CdS nanotubes) were identified using an S-4900 field emission scanning electron microscope (Hitachi High-technologies Co.), as shown in FIG. ₂ nm mean diameter and length and the surface area of the TiO ₂ measurements per cm ² of the TiO ₂ substrate of the tube with respect to an anode oxidation treatment, the sample for 1 hour at 60V, respectively 94.9 ± 11.1nm, 13.8 ± 1.1μm, and this was 581cm ² , For anodized samples at 30V for 12 hours, 63.4 ± 5.8 nm, 7.7 ± 0.3 μm and 485 cm ^2, respectively.

Formation and growth of CdS nanoparticles on TiO ₂ nanotubes during the SILAR process can be confirmed by monitoring changes in SEM images, X-ray diffraction (XRD) patterns, absorption spectra and elemental composition.

SEM images before and after the coating of CdS were confirmed using a S-4900 field emission scanning electron microscope (Hitachi High-technologies Co.). As shown in FIG. 2, the clean TiO ₂ nanotubes were well aligned with each other before CdS coating. It was confirmed that the Ti substrate was perpendicular to the underlying Ti substrate, and the TiO ₂ nanotubes after CdS coating were found to increase roughness by formation of CdS nanoparticles.

In addition, the XRD pattern of TiO ₂ nanotubes before and after CdS coating using a D / MAX-RC thin-film X-ray diffractometer (Rigaku Co.) scan speed, 1 ° / min; Cu Kα radiation, λ = 1.5418 Hz; The scan range was collected under the same conditions as 20 ° -70 °.

As a result, as shown in FIG. 3, it was confirmed that the anodized TiO ₂ nanotubes (gray solid line) before CdS coating were an amorphous phase having a smooth surface, and the TiO ₂ nanotubes (black solid line) after CdS coating were confirmed. ), A peak peculiar to CdS nanoparticle formation was identified ("S" represents a substrate peak).

In addition, the absorption spectra of TiO ₂ nanotubes before and after CdS coating were measured in diffuse reflectance mode using a V / 650 spectrophotometer (Jasco, Inc.).

As a result, as shown in FIG. 4, it was confirmed that the TiO ₂ nanotubes, which showed little absorbance in the visible light region, absorbed the visible light region by the formation of CdS nanoparticles after CdS coating.

Furthermore, as a result of confirming the absorption spectra according to the number of SILAR process cycles for CdS coating, as shown in FIG. 5, it was confirmed that the red-shift to the visible region in the ultraviolet after CdS coating.

In addition, the relative constituents of CdS-coated TiO ₂ nanotubes according to the number of SILAR process cycles for CdS coating were measured using Energy-dispersive X-ray spectroscopy, as shown in FIG. 6. The amount gradually increased after CdS coating.

Subsequently, the optical bandgap of the prepared TiO ₂ -CdS nanotube film was measured by tauc's extrapolation method (J. Tauc et al., J. Non-Cryst. Solids, 8: 569, 1972). It was.

As a result, as shown in Table 1, the optical bandgap of the TiO ₂ -CdS nanotube film decreased as the CdS coating process was repeated. This reduction implies a quantum confinement effect, where the actual size of CdS nanoparticles (e.g., CdS has a size of 2.36 nm after 4 cycles of SILAR process) for CdS smaller than 10 nm In the range of effect (Y. Wang et al., Phys. Rev. B, 42: 7253, 1990).

TiO ₂ Regeneration of Redox Enzyme Cofactors Using -CdS Nanotubes

The availability of CdS coated TiO ₂ nanotube films for photochemical NADH regeneration and enzymatic synthesis of organic compounds was tested.

Photoregeneration of NADH was performed by dipping TiO ₂ -CdS nanotubes into the reaction solution while irradiating light with a xenon lamp (450W) having a 420nm cut-off filter. Fill the quartz cell with 3 mL of a reaction solution of pH 7.5 (1 mM NAD ⁺ , 0.25 mM [Cp * Rh (bpy) H ₂ O] ²⁺ , 15 w / v% TEOA and 100 mM phosphate buffer) In the meantime, the ratio of the reaction volume to the external surface area of the photoelectrode was maintained at 1 cm ³ per cm ² . During NADH photoregeneration, the concentrations of NAD ⁺ and NADH were measured by measuring the absorbance of the reaction solution at 260 nm and 340 nm, respectively. The absorption coefficient of NADH at 340 nm is 6.22 mM ^-1 cm ^-1 .

As a result, as shown in Figure 7, the concentration of NAD ⁺ decreases over time, while it was confirmed that the concentration of NADH increases.

In addition, as a result of comparing the regeneration rate of NADH over time for TiO ₂ nanotubes without a CdS coating and TiO ₂ -CdS nanotubes of different sizes, as shown in Figure 8, TiO ₂ nanotubes without a coating of CdS Showed little regeneration of NADH, and the higher the pore diameter (94.9nm vs 63.4nm) for TiO ₂ -CdS nanotubes, the better the optical regeneration rate (50.3% vs 5.35 for 2 hours). %).

This means that dispersion of reactive species is an important factor for optimizing the optical regeneration system.

In addition, results of comparing NADH refresh rate based on the number of coating of CdS, the TiO ₂ -CdS prepared by four cycles of SILAR process, regardless of the size of the TiO ₂ nanotubes nanotube (4 × TiO ₂ -CdS) film is NADH It was confirmed that the regeneration rate was the best (Fig. 9).

These results indicate that as the number of CdS coatings increases, a large amount of light can be absorbed, while the effectiveness of channel blocking and charge separation of TiO ₂ nanotubes due to the formation of large CdS agglomerates decreases. It was assumed that it was because of losing.

FIG. 10 is a SEM photograph of TiO ₂ -CdS nanotubes prepared by 7 cycles of SILAR process, showing channel blocking by CdS aggregate formation.

On the other hand, recent studies have shown that smaller quantum dots inject electrons more efficiently into TiO ₂ than larger quantum dots, and the larger the bandgap, the more negative the CB boundary of CdS is, The driving force (ie, the difference in the position of the CB boundary of CdS and TiO ₂ ) is even greater (I. Robel et al., J. Am. Chem. Soc., 129: 4136, 2007).

That is, since CdS has a smaller size than TiO ₂ and the conduction band edge of CdS is at a more negative position than the conduction band boundary of TiO ₂ as shown in FIG. 11 (at least) 0.2V more negative), photogenerated electrons can be rapidly injected into TiO ₂ from CdS in a thermodynamically advantageous manner.

Thus, to confirm that efficient charge separation in TiO ₂ -CdS nanotubes can improve the efficiency of NADH photoregeneration, CdS coated Al ₂ O ₃ nanotubes (Al ₂ O ₃ -CdS nanotubes) and TiO The NADH photoregeneration efficiency of ₂ -CdS nanotubes was compared.

First, Al ₂ O ₃ nanotube films were prepared using commonly used anodized aluminum oxide film, and then Al ₂ O ₃ -CdS nanotube films were prepared by coating with CdS nanoparticles using SILAR method. SEM images before and after the coating of CdS were confirmed using a S-4900 field emission scanning electron microscope (Hitachi High-technologies Co.).

Was confirmed as a result, that, Al ₂ O ₃ nanotubes was confirmed that an CdS nanoparticles coated on the entire surface, Al ₂ O average diameter and length of the _third nanotube pores are respectively 211nm and 60μm, as shown in Figure 12 .

Subsequently, the NADH regeneration rate of TiO ₂ -CdS nanotubes and Al ₂ O ₃ -CdS nanotubes was measured, indicating that the Al ₂ O ₃ -CdS nanotube films had larger dimensions (average 211 nm pores than TiO ₂ -CdS nanotubes). 60μm diameter and length) and was further despite the large surface area (1cm ² has a 1131cm ²⁾ per substrate, it is shown a lower refresh rate, Al ₂ O ₃ -CdS nanotube film (FIG. 9).

This result is due to a high level of charge recombination, and as shown in FIG. 13, in the case of TiO ₂ -CdS nanotube films, electron injection from CdS to TiO ₂ is more negative than that of TiO _2. negative) Because of its electrical band level, it is thermodynamically advantageous to inhibit electron-hole recombination that favorably occurs in nanoscale semiconductor particles, while electrons excited in Al ₂ O ₃ -CdS nanotube films are TiO ₂ -CdS nanotubes. It is possible to recombine with holes to a higher level than the film, resulting in a lower efficiency of NADH photoregeneration (M means [Cp * Rh (bpy) H ₂ 0] ²⁺ complex).

Subsequently, in order to improve the optical regeneration rate of NADH, the crystallinity of the TiO ₂ nanotubes was adjusted through heat treatment. The higher the crystallinity of TiO _2, the lower the density of defects acting as electron trapping sites, and thus the higher the regeneration efficiency of NADH.

TiO ₂ nanotube films were prepared by anodizing Ti foil at 60 V for 1 hour and then annealing at room temperature, 150 ° C., 300 ° C. and 450 ° C. for 2 hours.

Crystallization of TiO ₂ was analyzed using multiple analysis tools such as SEM, XRD and Raman analyzer.

First, the TiO ₂ nanotubes according to the annealing temperature were confirmed using an S-4900 field emission scanning electron microscope (Hitachi High-technologies Co.). As shown in FIG. 14, the TiO ₂ nanotubes were annealed at a high temperature even after the annealing at high temperature. The tubular morphology remained, but the smooth surface was found to be rugged.

In addition, the XRD pattern of TiO ₂ nanotubes according to the annealing temperature by using a D / MAX-RC thin-film X-ray diffractometer (Rigaku Co.) scan speed, 1 ° / min; Cu Kα radiation, λ = 1.5418 Hz; Scan range was collected under the same conditions as 20 ° -70 °, and the size of the TiO ₂ nanocrystals was measured using a Raman analyzer (LabRAM HR UV / Vis / NIR, Horiba Jobin Yvon,). The size of TiO ₂ nanocrystals was measured using a shift of the Eg band peak position in Raman spectra according to previous studies (WF Zhang et al., J. Phys. D: Appl. Phys., 33: 912, 2000; D. Zhang et al., Adv. Funct. Mater., 16: 1228, 2006).

As a result, as shown in Fig. 15 and 16, after the amorphous TiO ₂ nanotubes at high temperature, it was confirmed that the crystallization in the anatase phase (Fig. 15), in the Raman spectra, annealing temperature As increased, the intensity of the peak corresponding to anatase TiO ₂ increased significantly with the red shift of the Eg band (FIG. 16).

Annealing at temperatures above 600 ° C. interferes with the tubular structure and causes phase transformation into the rutile phase.

Table 2 shows the size of the anatase nanocrystals measured by the method using the XRD and Raman spectroscopy, the size of the nanocrystals increased with increasing the annealing temperature.

Subsequently, TiO ₂ nanotubes having different crystallizations were coated with CdS, and then NADH photoregeneration was compared. As a result, as shown in FIG. 17, the size of the TiO ₂ nanocrystals increased with annealing temperature up to 300 ° C., while the 4 × TiO ₂ -CdS nanotube film had a photoregeneration efficiency of 49.9% to 75.2%. Increased 1.5 times. This result is due to the increased electron lifetime of TiO ₂ crystallization (S. Nakade et al., J. Phys. Chem. B, 106: 10004, 2002). However, TiO ₂ nanotubes treated at 450 ° C reduced their efficiency to 54.4%, and recent studies show that larger crystal formation reduces surface area and increases the efficiency of electron lifetimes in the efficiency of cofactor photoregeneration. It has been reported to counterbalance.

On the other hand, as a result of comparing the NADH optical regeneration rate of TiO ₂ nanotube film according to the number of coating of CdS after annealing at various temperatures, as shown in Figure 18, the four NdH regeneration rate is the case where four CdS coatings were made for all temperatures It confirmed that this was excellent.

In addition, the, TiO ₂ film (particulate TiO ₂ film) composed of nano-particles for comparative experiments to examine the effect of the morphology of the TiO ₂ film nanostructures (morphological effect) in the optical reproducing efficiency was prepared. TiO ₂ films composed of nanoparticles (about 15 μm thick) were prepared by the doctor-blade method using pastes composed of commonly used TiO ₂ nanoparticles and titanium tetraisopropoxide (TTIP) (D. Zhang et al. , Adv.Funct. Mater., 16: 1228, 2006). The prepared TiO ₂ film was annealed at room temperature overnight, and annealed at 150 ° C. for 10 minutes to interconnect the nanoparticles with each other through hydrolysis and condensation of TTIP to improve mechanical stability.

The formation of TiO ₂ films composed of nanoparticles was confirmed using SEM, XRD and Raman analyzer.

As a result, as shown in FIGS. 19 and 20, in the film composed of nanoparticles, TiO ₂ was similar in size (9.3 nm vs. 10.4 nm) to the TiO ₂ size in the tubular film annealed at 450 ° C. It was a nanocrystalline anatase phase.

The size of the anatase nanocrystals in the TiO ₂ film was characterized by the full width at half-maximum (FWHM) of the anatase peak 101 and the Eg band at Scherrer's equation (BD Cullity et al., Elements of X-ray diffraction, 2001) or Raman spectra. Calculation was made using the shift of the peak position.

Then, TiO _2, and nano-tube-type TiO ₂ film consisting of nano-particles is a result of performing the following each NADH regeneration tests coated with CdS compare the efficiency of NADH optical reproducing, as shown in Figure 21, the nano-tube-type TiO ₂ film It was confirmed that NADH can be regenerated at least four times more effectively than TiO ₂ composed of silver nanoparticles (FIG. 21A). These results show that the efficient dispersion of reactive species in the nanotubular film is an important factor for the high efficiency of NADH photoregeneration (Fig. 21B).

Thus, TiO ₂ -CdS nanotube films are easy to synthesize and have morphology control (JM Macak et al, Angew. Chem. Int. Ed., 44: 7463, 2005; K. Shankar et al., J. Phys. Chem. C, 113: 6327, 2009) Easy and efficient charge separation (PV Kamat, J. Phys. Chem. C, 112: 18737, 2008; W.-T. Sun et al., J. Am. Chem. Soc., 130: 1124, 2008) and the reaction species (reaction species) has the advantage of such a good dispersion through the nanotubes.

TiO ₂ Production of L-glutamate Using -CdS Nanotubes

For photoenzymatic synthesis of L-glutamate, a reductive amine reaction catalyzed by GDH (glutamate dehydrogenase) was coupled with photoregeneration of NADH from NAD ⁺ using TiO ₂ -CdS nanotube films. Reaction solution for photoenzymatic reaction: 1 mM NAD ⁺ , 0.5 mM [Cp * Rh (bpy) H ₂ O] ²⁺ , 5 mM a-ketoglutarate, 100 mM (NH ₄ ) ₂ SO ₄ , 40U GDH, 15w / v% It was prepared by mixing TEOA and 0.1M phosphate buffer (pH 7.4).

As a result, as shown in FIG. 22, L-glutamate was successfully synthesized by combining NADH photoregeneration and a reductive amination reaction catalyzed by a redox enzyme (ie, GDH).

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereby. something to do. It is therefore intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

Claims (29)

Irradiating a redox redox enzyme cofactor, which contains an oxidative redox enzyme cofactor, a metal oxide-inorganic photosensitive complex in nanotube form, and a sacrificial electron donor, to generate a reduced redox enzyme cofactor A photochemical regeneration method of a redox enzyme cofactor.
The method of claim 1, wherein the nanotube-type metal oxide-inorganic photosensitive composite is prepared by anodizing to prepare a nanotube-type metal oxide, and then using a successive ionic layer adsorption and reaction (SILAR) process. A photochemical regeneration method of a redox enzyme cofactor, which is prepared by coating an inorganic photosensitizer on a nanotube-type metal oxide.
The method of claim 1, wherein the inorganic photosensitizer is a nanoparticle selected from the group consisting of CdS, CdSe, CdTe, PbS, ZnS, InP and GaAs.
The photochemical regeneration of a redox enzyme cofactor according to claim 1, wherein the metal oxide is selected from the group consisting of TiO ₂ , SiO ₂ , Fe ₂ O ₃ , IrO ₂ , Co ₃ O ₄ and WO ₃ . Way.
The method of claim 1, wherein the oxidative redox enzyme cofactor is selected from the group consisting of NAD ⁺ , NADP ⁺ , FAD ⁺ and FMN ⁺ .
The photochemical regeneration method of redox enzyme cofactor according to claim 1, wherein the redox enzyme cofactor regeneration solution further contains a redox mediator.
7. The photochemical regeneration method of a redox enzyme cofactor according to claim 6, wherein the redox mediator is selected from the group consisting of methyl viologen, ruthenium II complex and rhodium III complex.
8. The method of claim 7, wherein the ruthenium II complex is (hexamethylbenzene-2,2'-bipyridinechloro) ruthenium (II).
8. The method of claim 7, wherein the rhodium III complex is (pentamethylcyclopentadienyl-2,2'-bipyridinechloro) rhodium (III).
The method of claim 1, wherein the sacrificial electron donor is triethanolamine (TEOA), ethylenediaminetetraacetic acid (EDTA), citric acid, formic acid, ascorbic acid, oxalic acid (Oxalic acid), an alcohol and an optical regeneration method of the redox enzyme cofactor, characterized in that selected from the group consisting of water.
The optical regeneration method of redox enzyme cofactor according to claim 1, wherein the light is selected from the group consisting of tungsten-halogen lamp light, xenon lamp light, short wavelength laser light and sunlight.
A composition for regeneration of a redox enzyme cofactor containing an oxidative redox enzyme cofactor, a metal oxide-inorganic photosensitive agent complex in the form of a nanotube, and a sacrificial electron donor.
The method of claim 12, wherein the nanotube-type metal oxide-inorganic photosensitive composite is prepared by anodizing to prepare a nanotube-type metal oxide, and then using a successive ionic layer adsorption and reaction (SILAR) process. Redox enzyme cofactor regeneration composition, characterized in that prepared by coating an inorganic photosensitizer on the metal oxide in the form of nanotubes.
The composition of claim 12, wherein the inorganic photosensitizer is a nanoparticle selected from the group consisting of CdS, CdSe, CdTe, PbS, ZnS, InP, and GaAs.
The composition of claim 12, wherein the metal oxide is selected from the group consisting of TiO ₂ , SiO ₂ , Fe ₂ O ₃ , IrO ₂ , Co ₃ O _4, and WO ₃ .
The composition of claim 12, wherein the oxidative redox enzyme cofactor is selected from the group consisting of NAD ⁺ , NADP ⁺ , FAD ⁺ and FMN ⁺ .
The composition for regeneration of a redox enzyme cofactor according to claim 12, wherein the redox enzyme cofactor regeneration solution further contains a redox mediator.
18. The composition of claim 17, wherein the redox mediator is selected from the group consisting of methylviologen, ruthenium II complex, and rhodium III complex.
19. The composition of claim 18, wherein the ruthenium II complex is (hexamethylbenzene-2,2'-bipyridinechloro) ruthenium (II).
19. The composition of claim 18, wherein the rhodium III complex is (pentamethylcyclopentadienyl-2,2'-bipyridinechloro) rhodium (III).
The method of claim 12, wherein the sacrificial electron donor is triethanolamine (TEOA), ethylenediaminetetraacetic acid (EDTA), citric acid, formic acid, ascorbic acid, oxalic acid (Oxalic acid), a redox enzyme cofactor regeneration composition, characterized in that selected from the group consisting of alcohols and water.
Method for preparing a metal oxide-inorganic photosensitive composite in the form of nanotubes comprising the following steps:
(a) preparing a metal oxide in the form of nanotubes through anodization; And
(b) coating an inorganic photosensitizer on the metal oxide in the form of nanotubes using a successive ionic layer adsorption and reaction (SILAR) process.
23. The method of claim 22, wherein the successive ionic layer adsorption and reaction (SILAR) process is performed four times.
In the method for producing a compound through a redox reaction of a substrate using a redox enzyme and its cofactor, the cofactor of the redox enzyme is regenerated using the composition for regenerating the redox enzyme cofactor of claim 12, Method for producing a compound, characterized in that for performing a redox reaction using the cofactor.
25. The method of claim 24, further comprising the steps of: (a) adding a substrate and a redox enzyme to the redox enzyme cofactor regenerating composition of claim 12 and then irradiating with light to regenerate the redox enzyme cofactor; And (b) obtaining a compound prepared by a redox enzyme reaction using the regenerated cofactor.
The method of claim 24, wherein the compound is selected from the group consisting of L-glutamate, Lactate, and alcohol.
27. The method of claim 26, wherein the substrate is selected from the group consisting of a-ketoglutarate, aldehydes and pyruvates.
The method of claim 24, wherein the redox enzyme is selected from the group consisting of glutamate dehydrogenase (GDH, glutamate dehydrogenase), alcohol dehydrogenase (ADH, alcohol dehydrogenase) and lactate dehydrogenase (LDH, lactate dehydrogenase) Method for preparing the compound.
The method of claim 25, wherein the light is selected from the group consisting of tungsten-halogen lamp light, xenon lamp light, short wavelength laser light, and sunlight.

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