JPH07117696B2 - Recording medium and image forming method using the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a recording medium utilizing a biochemical reaction of a photosensitizing dye protein held in a lipid film and an image forming method using the recording medium.

[Conventional technology]

As a medium for forming an image using light, a medium such as a silver salt photographic system using silver halide, an electrophotographic system using an electrostatic recording method, a resin plate making system using a photosensitive resin is generally used. Known to be.

[Problems to be solved by the invention]

The present inventors have paid attention to the fact that the selectivity (specificity) and reaction efficiency of a biochemical reaction observed in a living body are extremely high as compared with a physical or chemical reaction, and the physical or chemical reaction We have conducted various studies on recording media using biochemical reactions that can realize image formation with high-sensitivity and high-resolution light with less light irradiation energy than various recording media using chemical reactions. .

In the process, the present inventors focused on the photosensitizing dye protein, which is a substance that is present in the retina of a living body, etc. and has a very high sensitivity in the living body, which is involved in photosensing at a high resolution, and has a structure similar to that of The inventors have found that by using a photosensitizing dye protein having a function and capable of existing relatively stably at room temperature in a lipid film, it is possible to perform high-sensitivity, high-resolution optical recording with high energy efficiency and reach the present invention. did.

It is an object of the present invention to provide a novel recording medium utilizing a biochemical reaction and an image forming method using the same.

[Means for solving problems]

That is, the present invention provides a lipid membrane that retains a photosensitive dye protein having a function of receiving visible light and transporting ions, and a change in ion concentration due to ion transport by the photosensitive dye protein that receives visible light, or the lipid. An image forming method comprising: a recording medium having means for visualizing a change in membrane potential of a film; and a step of irradiating the recording medium with visible light according to recording information.

The photosensitive dye protein used in the recording medium of the present invention refers to a protein having a function of transporting various ions that have received light,
Various photosensitizing dye proteins can be used as long as they have such a function, and the types thereof are not limited.

As a typical example of such a photosensitizing dye protein, there is a so-called visual substance, and bacteriorhodopsin, halorhodopsin, etc. which have the same function as this visual substance can also be used.

Bacteriorhodopsin is the main component of the protein of the cell membrane (purple membrane) of highly halophilic bacteria belonging to the genus Halobacterium, such as Halobacterium halobium. Pumpability) [A.Danon, W.Stoeckenius; Pr
oc.Natl.Acad.Sci., USA, 71 , 1234 (1974)].

This bacteriorhodopsin is described, for example, by D. Qesterhelt and W. Stoeckenius [Method in Enzymology, 31 , 667-678].
(1974)], and extracted as a purple membrane from highly halophilic bacterium, and further, K-S.Huang, H.Bayley and HGKho
It can be obtained by removing lipids from the purple membrane obtained by the method described in rana [Proc. Natl. Acad. Sci., USA, 77, 323 (1980)].

In addition, halorhodopsin is a highly halophilic bacterium such as R _1m R, L ₃₃
It is a retinal protein found in a bacteriorhodopsin-deficient strain such as AA and has the property of transporting sodium ions upon receiving visible light [AYMatsuno and Y.Mukohata, B
iochem.Biophys.Res.Commun., 78 , 237 (1977); REMacD
onald, RUGreene, RDClark, EVLindley, J.Biol.Che
m., 254 , 11831 (1979)].

This halorhodopsin is derived from highly halophilic bacteria such as Y. Mukoha.
ta, Y.Sugiyama and Y.Kaji, J.Usukura and E.Yamada.Ph
otochem. Photobiol., L ₃₃ , 539 (1981).

In addition, in bacteriorhodopsin and halorhodopsin,
As described above, halorhodopsin functions to lower the pH under conditions in which the types of ions transported when receiving visible light are different and bacteriorhodopsin raises the pH. Therefore, the charge accumulation direction at the membrane potential formed when the membrane containing these photosensitive dye proteins is irradiated with visible light is opposite.

The membrane potential refers to the potential difference between the intracellular and extracellular fluids separated by the cell membrane in the case of cells.

In the recording medium of the present invention, the photosensitizing dye protein obtained by removing lipids from the purple membrane is retained in another lipid membrane, so that only the hydrogen ion concentration and the membrane potential change outside the artificial membrane can be extracted. It becomes possible and the sensitivity can be increased as compared with the purple film.

In the recording medium of the present invention, a known amphipathic compound capable of forming a monomolecular film or a multimolecular film can be used as the material for the lipid film that holds the photochromic protein. These lipid molecules capable of forming a membrane are composed of a long-chain alkyl group having 8 or more carbon atoms and a hydrophilic group. Cations such as, for example Anions such as, for example Non-ion such as, for example Any zwitterion such as

Of these lipid materials, glycerophospholipids such as phosphatidylcholine (lecithin), phosphatidylethanolamine, and diphosphatidylglycerol; sphingolipids such as sphingomyelin and ceramide cyatinine; glycosphingolipids such as cerebroside, sulfatide, and ceramide oligohexoside. And a glyceroglycolipid such as glycosyldiacylglycerol containing a carbohydrate as a hydrophilic group is a lipid that constitutes a biological membrane, the above-described photochromic protein is incorporated to form a lipid membrane that retains the photochromic protein, It can be said that the material is particularly suitable for allowing the protein to function efficiently.

The lipid membrane as referred to in the present invention is formed of the lipid material as described above and is composed of a lipid monolayer, or has a structure in which two lipid monolayers are laminated (lipid bilayer). Membranes) and lipid monolayers composed of three or more layers (lipid multi-layer membranes) can be used.

Among them, it is convenient to retain the photosensitizing dye protein in the lipid bilayer membrane, because the photosensitizing dye protein can be reconstituted into a form close to the structure in the living body and its function can be effectively used.

In the recording medium of the present invention, the means for visualizing the change in the ion concentration due to the transport of ions by the photochromic protein or the change in the membrane potential of the lipid membrane that holds the photochromic protein is in a form in which these changes can be visually recognized. And a reaction system, which includes, for example, a) a substance that develops, decolorizes, or discolors in response to a change in hydrogen ion concentration in a lipid membrane that retains the above-described photochromic protein. A substance which is trapped in or adsorbed on the surface of the membrane, b) a substance which develops, decolorizes or discolors in response to changes in hydrogen ion concentration, and Those coexisting in the immobilized region, c) Coloring, erasing, or discoloring depending on the change in membrane potential of the lipid membrane holding the photosensitizing dye protein The substances that having a structure which contains a region adjacent to the lipid membrane [B.Ehre
nberg, Z.Meiri and LMLoew, Photochem.Photobiol., 39
(2) , 199 (1984)], and various other methods capable of visualizing changes in hydrogen ion concentration and changes in electrochemical potential.

Examples of the substances used in the above a) and b) are so-called pH indicators such as cresol purple, bromothymol blue, neutral red, phenol red, cresol red, bromocresol purple, rosolic acid and bromophenol red. Further, natural pigments such as cochineal pigments, lac pigments, grape skin pigments, berry pigments, and corn pigments that change color depending on the hydrogen ion concentration can be produced.

However, the material used for the means for visualizing the change in ion concentration is not limited to these dyes, and it can be used in an aqueous solution in the pH range (about pH 5 to 8) where the activity of the photosensitizing dye protein used in the recording medium of the present invention can be obtained. Any one that can be effectively used can be used.

In order to obtain a recording medium with higher sensitivity, when the above pH indicators and dyes are used, the pH of the region containing these is adjusted in advance so that they are the most sensitively colored or discolored. good.

Further, the kind of material used for the visualization means may be appropriately selected according to the kind of ions transported by the photosensitive dye protein used.

On the other hand, examples of the substance that can be used in the above example c) include cyanine dyes, merocyanine dyes, safaline dyes, oxole dyes, and styryl dyes.

The lipid membrane holding the photosensitizing dye protein in the recording medium of the present invention is immobilized on a suitable substrate by a fusion adsorption method to a lipid layer formed on the substrate, an immobilization method by gel or the like to form the recording medium of the present invention. Obtainable.

The fusion and adsorption of a lipid membrane on a substrate means that a lipid layer is formed on a suitable substrate in advance and a lipid membrane containing a photochromic protein is fused on the layer, as shown in the following examples. It is a method to let.

Moreover, collagen, polyacrylamide, agarose, cellulose, etc. can be used as a constituent material of the gel for immobilization.

On the other hand, in order for the recording medium of the present invention to function, the presence of water is indispensable, but water may be contained in advance in the region containing the lipid film holding the photosensitizing dye protein, or in this region at the time of recording. May be supplied to

Hereinafter, an example of the recording medium of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic partial cross-sectional view of a recording medium of the present invention having a structure having a proteoliposome in which a photosensitizing dye protein is retained in the membrane of a liposome (closed foam membrane) composed of a lipid bilayer membrane.

In this recording medium, the photosensitizing dye protein is held in the membrane 3a in the lipid layer 2 on the substrate 1, and the above-mentioned visualization means such as a pH indicator can be formed on the outer surface 3c to adsorb the substance or It has a configuration in which the proteoliposome 3 contained in the chamber 3b is fused and adsorbed.

The substrate 1 may be made of resin, glass, ceramics, metal, cellulose or the like, if desired.

Among them, the membrane filter is convenient because it can be effectively used as it is for the immobilization of proteoliposomes and the adsorption operation of a pH indicator or the like to the proteoliposomes, which is used in the following examples.

The proteoliposome 3 in which the photosensitizing dye protein is retained in the membrane is, for example, E. Packer and W. Stoeckenius, J. Biol. Che.
m., 249 , 662 (1974) and K-S. Huang, H. Bayley and
HGKhorana, Proc.Natl.Acad.Sci., USA, 77 , 323 (198
[0]] is used to suspend the above lipids in a solution having an appropriate salt concentration, and sonicate as necessary to form liposomes. Can be obtained by using a method in which is added to a solution and incorporated into the formed lipid membrane.

In addition, from the product thus obtained, for example, column chromatography method, C. Lind, B. Hojeberg and H.
It is possible to separate and purify proteoliposomes incorporating a photochromic protein by using the ultracentrifugation method based on the sucrose concentration gradient method described in G. Khorana, J. Biol. Chem., 256 , 8298 (1981). .

Image formation using the recording medium having such a configuration is performed as follows, for example.

First, water is supplied to the area where the proteoliposome 3 is fixed so as to be held by moistening the recording medium as necessary.

Next, visible light is irradiated as shown in FIG. 2 according to the recorded information.

Then, the photosensitizing dye protein in the lipid membrane 3a in the irradiated portion (A) transports ions, and the hydrogen ion concentration in that area and the membrane potential of the lipid membrane change. Next, these changes are visualized by a substance adsorbed on the outer surface 3c of the proteoliposome or contained in the inner chamber 3b of the proteoliposome so as to form an image, thereby forming an image.

Further, the obtained image can be fixed by drying the recording medium to inactivate the photosensitizing dye protein.

Also, soak the once fixed image in dilute hydrochloric acid for several hours, then soak it in a 0.15M KCl (pH7.0) aqueous solution for a whole day and night to erase the recorded image, return the recording medium to the state before recording, and make a new recording. A recording medium may be used for the operation.

FIG. 3 is a schematic sectional partial view showing another embodiment of the recording medium of the present invention.

In the recording medium of this example, when the gel layer 4 is laminated on the substrate 1 using the above-mentioned materials, the proteoliposome 3 and the substance capable of forming the visualization means are mixed in the gel layer 4. Have.

On the other hand, FIG. 4 shows a schematic cross-sectional partial view of the recording medium of the present invention in which the planar lipid membrane 5 holding the photochromic protein 6 is formed on the substrate 1.

The planar lipid membrane 5 in this example can be formed as, for example, a Langmuir-Blodgett (LB membrane).

Specifically, LKTamm and HMMcConnell, Biophys.J.,
47 , 105 (1985), etc. When the LB film is formed on an appropriate substrate using the lipids listed above by the method described above, it can be formed by incorporating the desired photosensitizing dye protein into the LB film. .

The visualization means in this example can be formed by incorporating a material that can form the visualization means into the monomolecular film at the same time as forming the monomolecular film, or by adsorbing the material on the surface of the formed monomolecular film.

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 Halobacteriu by the method of D. Oesterhelt et al.
The purple membrane extracted from the m halobium R1 strain was prepared by
By treating with Triton X-100 according to the method of S. Huang et al., Lipid was removed from the obtained purple membrane to obtain a membrane protein, bacteriorhodopsin.

Next, the method of Y. Kagawa et al. [J. Biol. Chem., 246 , 5477 (197
170 mg of azolectin (soybean phospholipid) purified by the method of 1)] was dried to dryness under a nitrogen gas atmosphere, and 16 ml of 0.15M KCl solution containing 2% sodium cholate was completely transparent to the sodium cholate solution. And sonicated for about 15 minutes. Immediately after completion of the ultrasonic treatment, 3.2 mg of the bacteriorhodopsin obtained above was added to this treatment solution, and ultrasonic treatment was further performed for 10 seconds.

Neutral red 0.02% in the treatment solution obtained here
After adding 10 ml of the aqueous solution and stirring well, this solution was used as a dialysis membrane using a cellophane tube (manufactured by Union Carbide Co.) to contain 0.12% of sodium azide of 0.125%.
It was dialyzed against 5M KCl aqueous solution (adjusted to pH 7.0 with NaOH) 1.

For dialysis, the external solution (0.15M KCl aqueous solution containing 0.25% sodium azide) is replaced with new one every few hours,
Further, it was carried out for about one day until the pH of the external solution reached 7.0.

In this way, it was possible to obtain a proteoliposome in which neutral red was adsorbed to the outer wall of the dialysis membrane fluid and bacteriorhodopsin was retained in the membrane.

By the way, in the proteoliposomes obtained here, the purple color peculiar to bacteriorhodopsin disappeared, and the pH change due to visible light irradiation (using a 250W slide projector as a light source) using 0.15M KCl solution of these proteoliposomes. As a result of investigation, the sensitivity was about 10 times higher than that of the previously extracted natural purple membrane.

Next, a membrane filter (nitrocellulose filter; manufactured by Toyo Roshi Kaisha, Ltd., pore size 0.45 μm) was soaked in a decane solution (10 mg / ml) of azolectin as a dialysis membrane, and the proteoliposome previously obtained on the filter surface side. , 0.15M KCl and 20mM CaCl ₂ as an inner solution, 0.15M KCl (pH 7.0) as an outer solution, and the pH of the outer solution
The dialysis treatment was performed until it reached 7.0.

By this operation, the recording medium of the present invention was obtained in which the proteoliposome was fused and adsorbed to the azolectin layer formed on the surface of the Millipore membrane filter.

This recording medium has a red color due to neutral red, and a mask having a desired exposure pattern is superposed on the surface on which the proteoliposome is immobilized, and a visible light of about 30 is applied from above using a 250 W slide projector.
Irradiated for 2 seconds.

Then, the part irradiated with visible light turned yellow due to the increase in pH, and a clear image was obtained due to the difference in color from the part not irradiated (red).

The recording medium on which the image was formed was further heated and dried at 80 ° C. for 30 minutes to inactivate the bacteriorhodopsin and fix the image.

The recording medium was dipped in dilute hydrochloric acid for several hours, and then the solution was cooled to 0.
It was reusable by immersing it in 15M KCl aqueous solution (pH 7.0) for 24 hours.

Example 2 Polyester film as a substrate (14 × 14 mm. Thickness 100)
μm), the proteoliposome obtained in Example 1 and neutral red were immobilized in the gel layer as follows to obtain the recording medium of the present invention.

That is, 95 mg of acrylamide, 5 m of bisacrylamide
1 ml of 0.15M KCl solution containing g, 0.2% of tetraethylmethylenediamine, and 2 μM of proteoliposome obtained in Example 1 was prepared, and its pH was adjusted to 7.0 with hydrochloric acid. Further, 10 μl of a 10% aqueous solution of ammonium persulfate was added thereto to obtain a gel, which was coated on a substrate so that the dry film thickness was 5 μm, and further dried at 60 ° C. for 30 minutes to record the present invention. The medium was obtained.

When this recording medium was first wet with water and then irradiated with visible light through an exposure mask in the same manner as in Example 1, a clear image could be obtained. The image obtained is 80 ° C.
It could be fixed by a drying treatment for 1 hour.

Further, this recording medium was soaked in dilute hydrochloric acid for several hours to erase the image, and then re-immersed in an aqueous 0.15M KCl (pH 7.0) solution for a whole day so that it could be reused.

Example 3 First, 10 mg of a natural dye, cochineal dye, was used in place of neutral red, and the dialysis treatment for dye adsorption was performed with 0.15 M KCl (pH 4.8), and the pH of the external solution remained unchanged. Proteoliposomes were formed in the same manner as in Example 1 except that the above was performed.

Next, the proteoliposome previously obtained in the same manner as in Example 1 was fused and adsorbed to the same membrane filter as used in Example 1 which had been previously coated with azolectin to obtain an orange recording medium of the present invention. It was

When the recording medium thus obtained was irradiated with visible light through an exposure mask in the same manner as in Example 1, a clear red image could be obtained. Also, the obtained image is 80
It could be fixed by a drying process at 30 ° C. for 30 minutes.

Furthermore, this image can be erased by immersing the recording medium in dilute hydrochloric acid, and then 0.15 M KCl aqueous solution (pH 4.
8) It became possible to reuse it by soaking it in the whole day and night.

Example 4 The present invention was carried out in the same manner as in Example 2 except that the proteoliposome having the cotinyl dye obtained in Example 3 was adsorbed in place of the proteoliposome having the neutral red adsorbed therein obtained in Example 1. A recording medium was obtained.

When this recording medium was irradiated with visible light through an exposure mask in the same manner as in Example 1, a clear image could be obtained. Further, the obtained image could be fixed by a drying treatment at 80 ° C. for 30 minutes.

Furthermore, it could be reused in the same manner as in Example 3.

Example 5 First, the procedure up to the ultrasonic treatment of the solution to which bacteriorhodopsin was added was performed in the same manner as in Example 1.

Next, a styryl dye represented by the structural formula shown below in the treatment solution [4- (4'-dibutylaminophenyl-buta 1 ', 3'-diethyl) -1-δ-sulfobutyl-viridinium hydroxide] Was added so as to be 5 μM, and ultrasonication was further performed for 1 minute to obtain a proteoliposome containing a styryl dye inside the small bubbles.

Then, a treatment solution containing this proteoliposome was added to 0.
It was dialyzed in the same manner as in Example 1 against a 5M KCl (pH 6.5) aqueous solution. The dialysis was continued until the pH of the external solution remained unchanged.

After completion of the dialysis treatment, the proteoliposomes obtained as described above in the same manner as in Example 1 using the inner solution of the dialysis membrane were fused and adsorbed to the Millipore membrane filter immersed in the azolectin solution to give the recording medium of the present invention. Obtained.

When the recording medium thus obtained was irradiated with visible light through an exposure mask in the same manner as in Example 1, only the light-irradiated portion was fluorescent (about 600 n
m) was emitted, and a clear image was obtained due to the difference in the presence or absence of fluorescence from the portion not irradiated with light.

By the way, in the present embodiment, it is about 1000 times (20 microseconds) as compared with the recording media obtained in the previous embodiments 1 to 4.
The response speed to light was obtained.

Further, the obtained image could be fixed by a drying treatment at 80 ° C. for 30 minutes.

Example 6 A proteoliposome containing quinaldine red in the inside of small bubbles was obtained in the same manner as in Example 5 except that quinaldine red was used instead of the styryl dye, and this was then used in Example 2.
A recording medium was obtained by fixing the gel layer on the substrate in the same manner as in.

When the recording medium thus obtained was irradiated with visible light through an exposure mask in the same manner as in Example 1, only the light-irradiated portion emitted fluorescence due to a change in membrane potential,
A clear image was obtained due to the difference in the presence or absence of fluorescence from the portion not irradiated with light.

Example 7 First, a hexane-ethanol mixed solution (9: 1, v / v) containing 1 mM of phospholipid azolectin was developed in a Langmuir water tank. Next, the surface pressure of the developed azolectin monolayer on the water surface was maintained at 40 dyn / cm ² , the non-alkylated glass plate was held vertically, and after slowly inserting it below the water surface, this glass plate was placed vertically. It was slowly pulled out from the water tank while keeping it to obtain a monomolecular film in which the hydrophilic group of the azolectin was oriented toward the glass plate.

Next, the aqueous solution containing 1 mM of the proteoliposome containing bacteriorhodopsin obtained in Example 1 was developed in a Langmuir water tank. By this operation, the proteoliposome was destroyed and a lipid monolayer containing bacteriorhodopsin was formed at the gas-liquid interface. The surface pressure of this monolayer is about 40 dyn /
Keeping the cm ² level, the glass plate on which the azolectin monolayer was formed is horizontal, and the monolayer formed in the Langmuir water tank is superposed from above from the azolectin monolayer formation surface, and the bacterio A monomolecular cumulative planar membrane was formed with a lipid monolayer containing rhodopsin.

Finally, the pH of the obtained monomolecular cumulative film was adjusted to 7.0, the surface thereof was brought into contact with a 0.02% neutral red aqueous solution, and the neutral red was adsorbed thereto to obtain a recording medium.

When the sensitivity of the obtained recording medium was examined in the same manner as in Example 1, the sensitivity was higher than that of the natural purple film obtained in Example 1.

It is assumed that this is because each molecule of bacteriorhodopsin was regularly arranged in a certain direction.

When this recording medium was irradiated with visible light through an exposure mask in the same manner as in Example 1, a clear image could be obtained. Further, the obtained image could be fixed by a drying treatment at 80 ° C. for 30 minutes.

On the other hand, a membrane filter is used instead of the glass plate,
When neutral red was formed into a monolayer of bacteriorhodopsin, a recording medium was obtained in the same manner as above except that it was added at a concentration of 0.02% at the same time and incorporated into the monolayer. Also in the medium, high sensitivity was obtained similarly to the above, and good recorded images were obtained.

〔The invention's effect〕

The recording medium of the present invention has a structure in which a photosensitizing dye protein is retained in a lipid membrane and its characteristics can be effectively utilized, and the recording medium of the present invention provides high sensitivity using a biochemical reaction,
It has become possible to form images with high resolution.

Further, the recording medium of the present invention can be made a recording medium with higher sensitivity by having a constitution in which the photosensitizing dye protein is held in the lipid monolayer.

Further, since the recording medium of the present invention utilizes a biochemical reaction that can be controlled by simple operations of drying and replenishing water, it can be stored without being exposed to light unnecessarily if it is kept in a dry state. By replenishing water at the time of use, good image formation can be performed at any time. Moreover, the image formed by drying can be easily fixed, and the recording medium once formed can be reused by immersing the recording medium once in dilute hydrochloric acid or the like to eliminate the pH change generated during image formation.

[Brief description of drawings]

FIGS. 1, 3 and 4 are schematic partial cross-sectional views showing examples of each aspect of the recording medium of the present invention, and FIG. 2 is a diagram showing a process in the recording method of the present invention. 1: substrate, 2: lipid layer 3: proteoliposome 4: gel layer, 5: planar lipid membrane 6: photosensitizing dye protein

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Masanori Sakuranaga 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-60-86540 (JP, A) JP-A-SHO 59-197849 (JP, A) JP 62-11158 (JP, A) JP 58-52637 (JP, A) JP 4-22256 (JP, B2) JP 4-47892 (JP, B2) JP-B 62-45539 (JP, B2) JP-B 5-86273 (JP, B2)

Claims (10)

[Claims] 1. A lipid membrane having a photosensitizing dye protein having a function of receiving visible light and transporting ions, and a change in ion concentration due to ion transport by the photosensitizing dye protein receiving visible light or the lipid. And a means for visualizing changes in the membrane potential of the membrane. 2. The recording medium according to claim 1, wherein the photosensitive dye protein is bacteriorhodopsin. 3. The recording medium according to claim 1, wherein the photosensitizing dye protein is halorhodopsin. 4. The recording medium according to claim 1, wherein the photosensitive dye protein is retained in a lipid bilayer film. 5. The method according to claim 1, wherein the visualization means contains a substance that develops, disappears or changes color according to a change in hydrogen ion concentration or a change in membrane potential of a lipid membrane.
The recording medium according to the item. 6. A lipid membrane holding a photosensitizing dye protein that receives visible light and transports ions, and a change in ion concentration due to ion transport by the photosensitizing dye protein that receives visible light or the membrane of the lipid film. An image forming method comprising a step of irradiating a recording medium having a means for visualizing a potential change with visible light according to recorded information. 7. The image forming method according to claim 6, wherein the photosensitive dye protein is bacteriorhodopsin. 8. The image forming method according to claim 6, wherein the photosensitive dye protein is halorhodopsin. 9. The image forming method according to claim 6, wherein the photosensitizing dye protein is retained in a lipid bilayer film. 10. The visualizing means, which develops color according to a change in hydrogen ion concentration or a change in membrane potential of a lipid membrane,
The image forming method according to claim 6, further comprising a substance that erases or changes color.