JP2509573B2 - Light / heat-frequency conversion function film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a light / heat-frequency conversion functional film.

(Prior Art) The development of transistors, ICs, LSIs, and VLSIs based on silicon-based semiconductor technology has laid the foundation for today's electronics. On the other hand, with the elucidation of life or biological phenomena, expectations for the development of materials and devices based on new ideas unique to biological phenomena are increasing. This is based on the idea that by imitating a biological phenomenon, a new electronics technology will be carried out in terms of information processing, recognition, memory, etc. by an action different from the conventional thought.

By the way, of the many phenomena peculiar to biological systems, the most basic one is not the action based on the thermodynamic equilibrium that biological systems have usually considered, but the nonlinear nonequilibrium far away from equilibrium. It is becoming clear from various facts that it consists of phenomena that occur in states. Looking at this from another perspective, it can be said that this field also includes an unprecedented new idea of electronics.

A typical example resulting from such a non-linear non-equilibrium system is an oscillation phenomenon from a biological membrane or an artificial membrane (functional membrane) imitating it. An oscillation phenomenon using such a functional film will be described with reference to FIG. First, a partition wall 3 in which a porous membrane (functional membrane) 2 containing lipid molecules is attached in the center of a container 1
Is divided into two chambers, one chamber 4a containing, for example, a 0.1 molar KCl solution, and the other chamber 4b containing a 0.01 molar KCl solution. Subsequently, a constant current of about 10 ⁻⁷ A / cm ² is passed from the current applying power source 5 through the current applying electrodes 6a and 6b inserted into each solution to each solution maintained at 20 ° C. By such an operation, the periodic oscillation pattern shown in FIG. 2 can be observed by the electrometer 8 connected to the membrane potential measuring electrodes 7a and 7b inserted in each solution. Such an action can be regarded as an artificial generation of the excitement phenomenon of the biological membrane.

In the functional film described above, the oscillation period, waveform, and amplitude change due to salt concentration, current value, and other external pressure.
Conventionally, attempts have been made to read the information from the displacement of the oscillation pattern of the functional film due to the change in the current value itself as information (signal). However, the displacement of the oscillation pattern of the functional film due to changes in the external environment, which is mainly due to physical factors such as the current value, generally has extremely poor reproducibility with respect to the stimulus, and is distinguished from noise due to unintentional small changes in the external environment, or steady state. However, there is a problem in that it is difficult to maintain a general state, and the discernability of information is poor.

(Problems to be Solved by the Invention) The present invention has been made in order to solve the above-mentioned conventional problems, and is accompanied by a chemical active change by light or heat, rather than a physical change in the external environment. The present invention intends to provide a light / heat-frequency conversion function film in which the displacement of the oscillation pattern occurs.

[Structure of the Invention] (Means for Solving the Problems) The present invention comprises a bilayer membrane composed mainly of lipid molecules partitioning two aqueous solutions into two chambers, or lipids accumulated on a porous membrane. In a functional film comprising a molecular film or a polymer film in which lipid molecules are dispersed, the functional film having a self-excited oscillating action by an ion concentration difference between the respective aqueous solutions, an external pressure change, and an external current voltage application. Add a substance that causes a chemical reaction by light or heat to the membrane containing lipid molecules, or
Alternatively, the light / heat-frequency conversion functional film is characterized in that the waveform or amplitude of the frequency generated by the self-sustained pulsation is changed by either binding to the lipid molecule.

Examples of the lipid molecule include dioleyl phosphate, triolein, monoolein, and other phospholipid molecules.

Examples of the above-mentioned porous membrane include cellulose-based porous filters such as acetyl cellulose, fluororesin-based, and vinyl chloride resin-based porous filters.

Examples of the polymer film include general-purpose polymer films such as polystyrene, polyethylene and polypropylene.

As the substance which causes a chemical reaction by the light or heat, those having various reaction forms can be used,
In particular, the frequency, waveform, and amplitude forms of self-excited oscillation change only when external light is applied or heat is applied, and when these energies are cut off from the outside, the reaction returns to the original form, or due to external energy. Self-oscillation frequency, waveform,
It is desirable to have a reaction in which the form of amplitude changes and the same form is maintained even if these energies are cut off from the outside, but the original form is restored by applying different energy. As a substance that causes such a reaction, a substance that undergoes a proton transfer reaction such as ketone-type and enol-type tautomerism when excited, or a heterocyclic cleavage reaction such as photochromism of a spiropyran-based molecule to a merocyanine-based molecule is performed. Cis-like substances, azobenzenes, stilbenes, etc.
Examples thereof include a substance that undergoes trans isomerization, a substance that undergoes strain modification such as a reaction between norbonadiene and quadxylene, or a substance that performs an electron transfer reaction between two molecules of an electric donor and an electron acceptor. . The molecular structure of such a substance is not particularly limited, but the Random
When a lipid membrane is prepared by utilizing the hydrophilic / hydrophobic group of a substance such as the projet method, a system having a hydrophilic / hydrophobic group as well as a lipid is desirable.

Further, in order to produce a functional membrane of the present invention, for example, a functional membrane in which lipid molecule membranes are accumulated in the pores of a porous membrane, a suitable amount of a substance that causes a chemical reaction by light or heat is mixed in a solution of lipid molecules, A method of dipping and fixing the mixed solution on the porous membrane can be adopted.

(Function) The light / heat-frequency conversion functional film of the present invention is as shown in FIG. 2 described above in a state in which a substance that causes a chemical reaction by light or heat mixed into the film from the outside is not stimulated. Periodic oscillation is made. On the other hand, when light or heat is applied to the functional membrane from the outside to give a stimulus, the substance inside the lipid molecule causes a chemical reaction, and its molecular structure or electronic structure changes,
Since it directly affects the periodic oscillation of the functional film, the frequency, waveform, and amplitude of the oscillation are forcibly changed. And
The substance returns to its original state by blocking external light or heat or applying different light or heat, and the form of interaction with lipid molecules also returns to its original state, so the oscillation pattern is the same as before the reaction. It becomes a form.

As described above, the light / heat-frequency conversion function film of the present invention does not indirectly displace the oscillation pattern by the change of the conventional physical condition, but the chemical active change directly generated in the film by light or heat. If the light or heat is used as information (signal) in order to displace the oscillation pattern by utilizing, the conversion of the signal, the maintenance of reproducibility, the speeding of the response, the improvement of the sensitivity can be achieved, and the identification of the information The recognition accuracy can be significantly improved.

(Examples of the Invention) Examples of the present invention will be described in detail below.

Example 1 2 mol% of 1'-octadecyl-3 ', 3'-dimethyl-6-nitrospiro (2H-1-benzopyran-) was added to a porous filter made of acetyl cellulose having a pore size of 8 μm.
A functional film was prepared by dipping and adding a mixed film of dioleyl phosphate containing 2 ', 2'-indoline).

The functional film having the above-described structure is attached to the partition wall 3 which divides the inside of the container 1 shown in FIG. 1 into two chambers, one chamber 4a has a 0.1 molar KCl solution, and the other chamber 4b has a 0.01 molar KCl solution. After accommodating each of the solutions, a constant current of about 10 ^-7 A / cm ² was applied from the current application power source 5 through the current application electrodes 6a and 6b inserted into each solution to each solution maintained at 25 ° C. By the way
An oscillation pattern having a frequency of about 1 Hz could be obtained by the electrometer 8 connected to the membrane potential measuring electrodes 7a and 7b inserted in each solution. When the functional film was externally irradiated with light of 365 nm in this state, the frequency of the oscillation pattern was changed to 1.5 Hz, and the state was maintained even after the light irradiation was cut off. After that, when the functional film was irradiated with 545 nm light,
It was observed that the frequency of the oscillation pattern returned to the original 1 Hz. This action corresponds to the isomerization of the spiropyran compound used, 1'-octadecyl-3 ', 3'-dimethyl-6-nitrospiro (2H-1-benzopyran-2', 2'-indoline), to merocyanine. It is a thing.
Further, the frequency change due to the above reaction was hardly affected by the temperature change of ± 0.1 ° C, the vibration of the outside world, and the like.

Example 2 Four layers of L-α-dioleylphosphatidylcholine containing 4 mol% of 4-carboxy-4′-octadecyloxyazobenzene in a porous filter made of tetrafluorocarbon having a pore size of 0.2 μm by the Langmuir-Blodgett method. A functional film was prepared by accumulating in the form of a bilayer film.

The functional film having the above-mentioned configuration is attached to the partition wall 3 which divides the inside of the container 1 shown in FIG. 1 into two chambers, and one of the chambers 4a has a 0.5 molar NaCl solution and the other chamber 4b has a 0.5 molar KCl solution. When each of the solutions was stored and kept at 25 ° C., an oscillation pattern with a frequency of 0.5 Hz could be obtained by the electrometer 8 connected to the membrane potential measuring electrodes 7a and 7b inserted in each solution. In this state, when the functional film was irradiated with light of 450 nm from the outside, the frequency of the oscillation pattern changed to 0.8 Hz, and the state was maintained even after the light irradiation was cut off. Then, when the functional film was irradiated with heat rays from the outside by a CO ₂ laser, it was observed that the frequency of the oscillation pattern returned to the original 0.5 Hz. This action corresponds to the isomerization of the used 4-carboxy-4'-octadecyloxyazobenzene from the trans isomer to the cis isomer.
Further, the frequency change due to the above reaction was hardly affected by the temperature change of ± 0.1 ° C, the vibration of the outside world, and the like.

[Effects of the Invention] As described in detail above, according to the light / heat-frequency conversion functional film of the present invention, the oscillation pattern of the oscillation pattern is not accompanied by a physical change in the external environment but by a chemical active change by light or heat. Displacement occurs, and by converting the light or heat into information (signal), signal conversion, reproducibility is maintained, response speed is increased, and sensitivity is improved, and the accuracy of identification or recognition of the information is significantly improved. It has a remarkable effect.

[Brief description of drawings]

FIG. 1 is a sectional view showing an apparatus for measuring the potential of a functional film, and FIG. 2 is a diagram showing an example of an oscillation pattern of the functional film. 1 ... container, 2 ... functional film, 4a, 4b ... chamber, 5 ... current applying power supply, 8 ... electrometer.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location H03K 3/00 H03K 3/00

Claims (1)

(57) [Claims] 1. A bilayer membrane containing lipid molecules as a main component, which divides two aqueous solutions into two chambers, a lipid molecule membrane accumulated on a porous membrane, or a lipid molecule-dispersed high molecule. In a functional film composed of a molecular film and having a self-excited oscillating action by the ion concentration difference between the respective aqueous solutions, the change of external pressure, and the application of an external current voltage, a chemical reaction is caused by light or heat in the film containing the lipid molecule. Add the resulting substance or
Alternatively, a light / heat-frequency conversion functional film, wherein a waveform or amplitude of a frequency generated by the self-sustained pulsation is changed by being bonded to the lipid molecule.