JP3913744B2 - Lipid membrane production equipment - Google Patents

Description

  The present invention relates to a lipid membrane production apparatus.

  In today's environment, there are many substances (broadly toxic substances) that are harmful to living organisms. For example, trihalomethane in tap water and dioxins in the atmosphere come to mind, but there are only a few other examples, but so-called poisons such as cyan, cadmium, and volatile organic substances (cis-1,2-dichloroethylene, trichlorethylene, tetrachloroethylene). Contamination of raw water and groundwater due to water is also occasionally on the newspaper.

As a sensor for detecting such a toxic substance in real time, a lipid membrane production device that produces a lipid bilayer membrane automatically by producing a lipid membrane in an aqueous solution with a lipid solution discharge nozzle has been disclosed (for example, (See Patent Document 1 and Patent Document 2). In this apparatus, the produced lipid bilayer membrane is used as a sensor probe, and a toxic substance is detected by an electrochemical technique. In general, such an apparatus has a plurality of water tanks, generates a lipid bilayer membrane that can act on a part of the water tank partition walls, and measures the potential difference between the reference liquid and the sample liquid sandwiching the water tank partition walls with electrodes. It is a mechanism for detecting poisonous substances.
JP 2001-91494 A (paragraph number “0008”, FIG. 3) Japanese Patent Laying-Open No. 2003-194772 (paragraph numbers “0009” to “0014”, FIG. 1)

  The initial lipid membrane produced in the conventional lipid membrane production method described above is a thick lipid membrane. Then, due to the natural thinning of the lipid membrane, a lipid bilayer membrane (black membrane) is produced via a lipid multilayer membrane, but the lipid membrane produced by this method is very thick, so the diffusion of the solvent that dissolves the lipid Therefore, the progress of thinning of the lipid membrane is very slow, and it is the present situation that it is necessary to spend a long time until the lipid membrane is converted into a bilayer membrane.

  Further, when the lipid solution discharge nozzle is in an aqueous solution, the lipid solution may be emulsified by backflow of the surrounding aqueous solution into the lipid solution discharge nozzle. Alternatively, leakage of the lipid liquid may occur from the nozzle waiting for the discharge operation. Thus, the lipid membrane produced | generated using the lipid liquid containing an emulsion contains a large amount of emulsion, and has become the obstruction | occlusion of the production | generation of a lipid bilayer membrane by thinning of a lipid membrane.

  Furthermore, the smaller the amount of lipid ejected by the sensor device, the thinner the lipid membrane produced, and the shorter the time to convert from lipid membrane to lipid bilayer membrane, so it is also important to minimize the amount of ejected droplets It is. Conventionally, in order to produce a lipid membrane that does not contain an emulsion, when the lipid solution is discharged, the portion of the lipid solution that contains the emulsion at the tip of the nozzle and the subsequent lipid solution are skipped at a time. For this reason, there is a problem that not only does the amount of lipid discharged per time increase and the running cost increases, but it also takes time to convert the lipid multilayer to the lipid bilayer membrane.

  In view of the above problems, an object of the present invention is to provide a lipid membrane preparation apparatus that prevents the lipid liquid from being emulsified and quickly generates a stable lipid bilayer membrane.

  In order to achieve the above object, the present invention is characterized in that the first aqueous solution container, the third aqueous solution container, the first aqueous solution container, and the second aqueous solution container are located between the first aqueous solution container and the second aqueous solution container. A lipid membrane production apparatus comprising a partition wall having pores and a discharge means for discharging a lipid liquid to a through-hole, and comprising a supply means for alternately supplying lipid liquid and fluid to the discharge means This is the gist. Here, the “ejection means” refers to, for example, a lipid fluid ejection nozzle that ejects a lipid fluid by a jet water flow or the like.

  According to the lipid membrane production apparatus according to the features of the present invention, it is possible to prevent the lipid liquid from being emulsified and to quickly produce a stable lipid bilayer membrane.

  In the lipid membrane production apparatus according to the feature of the present invention, the supply means is preferably a pump for supplying a lipid liquid and a pump for supplying a fluid. Thus, lipid liquid and fluid can be easily supplied alternately by using a pump.

  Moreover, in the lipid membrane production apparatus according to the feature of the present invention, it is preferable that a fluid is present at the distal end of the ejection means during the ejection operation standby. For example, when a lipid solution discharge nozzle is used as the discharge means, the tip of the nozzle is blocked with a fluid, so that the lipid solution does not come into contact with the solution around the nozzle, and emulsification can be prevented.

  Moreover, in the lipid membrane production apparatus according to the features of the present invention, the fluid is preferably an inert fluid that does not react with the lipid solution and the aqueous solution. By using the inert fluid in this manner, the fluid does not react with the lipid solution or the solution around the discharge device, so that emulsification can be prevented and a stable lipid bilayer membrane can be generated.

  ADVANTAGE OF THE INVENTION According to this invention, the lipid membrane preparation apparatus which prevents the emulsification of a lipid liquid and produces | generates a stable lipid bilayer membrane rapidly can be provided.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones. Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(Lipid membrane production equipment)
In the embodiment of the present invention, the lipid liquid and fluid are alternately supplied to the discharge means to prevent the lipid liquid from being emulsified and to promote the thinning from the lipid multilayer film to the lipid bilayer film. The apparatus will be described.

  As shown in FIG. 1, the lipid membrane production apparatus according to the present embodiment includes a sample liquid storage part (first aqueous solution storage part) 3, a reference liquid storage part (second aqueous solution storage part) 4, and a sample liquid. A partition wall 5 having a through hole, located between the container 3 and the reference liquid container 4, a discharge means for discharging the lipid liquid into the through hole (for example, a lipid liquid discharge nozzle 2), and a lipid to the discharge means Supply means (for example, lipid liquid supply pump 11, fluid supply pump 12) for alternately supplying liquid and fluid, and a potential difference between the electrodes 6 and 7 by the measuring device 8, or a lipid membrane or lipid bilayer membrane Detecting means for measuring a membrane potential or the like. In addition, although the lipid membrane 1 in FIG. 1 is a thick lipid membrane initially produced in the through-hole, it will convert into the lipid bilayer membrane which consists of a molecular bilayer with progress of time.

  An electrode 7 is installed inside the sample liquid storage unit 3, and this electrode 7 is inserted into the sample liquid. Similarly, an electrode 6 is installed inside the reference liquid storage portion 4, and this electrode 6 is inserted into the reference liquid. The measuring device 8 measures the membrane potential of the lipid membrane 1 using the electrode 6 and the electrode 7. For example, an electrometer is used as the measuring device 8. Data obtained by the measuring device 8 can be recorded by the recorder 9. As the sample liquid, for example, groundwater is used, and the type and amount of poisons and the like contained in the groundwater are detected by the detection means.

  The sample liquid storage unit 3 is provided with a sample liquid circulation port 21 for injecting and discharging the sample liquid. In FIG. 1, there is one sample liquid circulation port 21, but the lipid membrane production apparatus according to the present embodiment provides a plurality of circulation ports by dividing the injection port and the discharge port, so that injection and discharge can be performed simultaneously. And it may be performed continuously. Similarly, a reference liquid circulation port 20 is provided in the reference liquid storage unit 4 to inject and discharge the reference liquid. In FIG. 1, there is one reference liquid flow port 20, but the lipid membrane production apparatus according to the present embodiment provides a plurality of flow ports by dividing the injection port and the discharge port, so that injection and discharge can be performed simultaneously. And it may be performed continuously. When a lipid membrane is used as the sensor membrane, the sample liquid can be continuously injected from the flow port 21, and changes in membrane potential caused by the interaction of the sample contained in the sample liquid with the lipid membrane are measured. By doing so, the sample can be detected.

The partition wall 5 is located between the sample liquid storage part 3 and the reference liquid storage part 4 and is made of, for example, Teflon ^TM (poly-tetra-fluoro-ethylene (-CF2-CF2-) n) having a thickness of about 25 μm. . The partition wall 5 has one or more through holes, and the lipid membrane 1 is formed in the through holes. The through hole has a circular shape with a diameter of 10 to 1000 μm and a depth of about 25 μm. A desirable through-hole diameter is 100 μm to 600 μm.

  The lipid liquid discharge nozzle 2 is an ink jet-like device, and discharges a lipid liquid into a through-hole by a jet water flow or the like, thereby producing a lipid membrane 1 in which both the sample liquid and the reference liquid are in contact with the through-hole. In FIG. 1, the lipid solution ejection nozzle 2 is installed in the sample solution storage unit 3, but may be installed in the reference solution storage unit 4.

  The lipid liquid supply pump 11 supplies the lipid liquid to the tube 14 connected to the lipid liquid discharge nozzle 2. The fluid supply pump 12 supplies fluid to the tube 14 connected to the lipid liquid discharge nozzle 2. At this time, the lipid liquid and the fluid merge at the merge section 13 and are alternately introduced into the tube 14. That is, in the tube 14, as shown in FIG. 2, the lipid liquid 16 and the fluid 15 flow alternately. The amount and flow rate of each of the lipid liquid and the fluid are managed by a control device (not shown), and the lipid liquid supply pump 11 and the fluid supply pump 12 send a predetermined amount of lipid liquid and fluid to a predetermined flow rate based on a signal from the control device. Send out. As the tube 14, for example, a Teflon tube or the like is used.

  In addition, when the fluid to be supplied is a gas, the fluid supply pump 12 can use an air compressor, an air pump, or a system that can supply gas (for example, supply of gas by a gas line or a gas cylinder). Is not to be done.

  Moreover, the fluid supplied should just be an inert fluid which does not react with a lipid liquid and aqueous solution. Further, as shown in FIG. 1, when the lipid liquid discharge nozzle 2 is inserted into the sample liquid, the fluid needs not to react with the sample liquid. Similarly, when the lipid liquid discharge nozzle 2 is inserted into the reference liquid, the fluid needs not to react with the reference liquid.

  As the fluid, for example, a fluid such as an inert gas or sol can be used, but the use of an inert gas is preferable. As the inert gas, for example, air, nitrogen gas, carbon dioxide, argon or the like can be used, but it is not particularly limited thereto.

  Further, the lipid liquid discharge nozzle 2 is not in the lipid liquid 16 at the tip 2a of the lipid liquid discharge nozzle 2 as shown in FIG. , Fluid 15 is present. The tip 2a of the lipid liquid discharge nozzle 2 is blocked by the fluid 15, and the lipid liquid 16 does not come into contact with the aqueous solution around the lipid liquid discharge nozzle 2.

  In addition, the fluid supply amount can block one discharge lipid droplet for producing the lipid membrane 1 and the next discharge lipid droplet, and is used for discharging a lipid liquid while waiting for the discharge operation. There is no particular limitation as long as the contact with the lipid solution and the aqueous solution around the lipid solution discharge nozzle 2 can be prevented by remaining at the tip of the nozzle 2. Therefore, the fluid supply amount is set to an appropriate amount that satisfies the above conditions.

  In addition, lipid bilayer membranes do not cause any changes in lipid bilayer membranes caused by the action of sample quality contained in aqueous solutions (for example, changes in electrical signals, ion permeability, luminescence, fluorescence, absorption spectra, thermal changes, etc.). Utilizing this, it acts as a sensor probe that detects the presence and concentration of the sample contained in the aqueous solution. Examples of such lipid bilayer membranes include lipid bilayer membranes substantially composed only of lipids, lipid bilayer membranes into which various proteins, molecules and substances are introduced. Various sensors according to specific contents such as the purpose of measurement or measurement object can be manufactured by appropriately selecting lipids, proteins, molecules, substances, and the like.

  As lipids used in the lipid membrane production apparatus according to the present embodiment, for example, phospholipids, glycolipids, fluorescent lipids, boundary lipids, cholesterol, sphingolipids, and the like, or synthetic lipids can be used. It is not limited to these.

(Action and effect)
According to the lipid membrane production apparatus according to the present embodiment, the lipid solution 16 contacts the solution around the lipid solution discharge nozzle 2 by alternately supplying the lipid solution 16 and the fluid 15 to the lipid solution discharge nozzle 2. Without emulsifying the lipid solution. In addition, since the lipid liquid and the fluid are alternately filled in this way, the amount of lipid liquid discharged at a time is reduced, leading to a reduction in running cost.

  Furthermore, since there are few lipid liquids, a thin lipid membrane is produced and the conversion time to a lipid bilayer can also be shortened. Conventionally, conversion from a lipid multilayer to a lipid bilayer took several hours, but according to the lipid membrane production apparatus according to the present embodiment, a lipid membrane can be transferred from a lipid multilayer to a lipid in a few seconds to a few minutes. It can be converted to a bilayer.

  Therefore, according to the lipid membrane production apparatus according to the present embodiment, a stable lipid bilayer membrane can be rapidly generated.

  Moreover, according to the lipid membrane production apparatus according to the present embodiment, the lipid solution and the fluid can be easily supplied alternately by using the lipid solution supply pump and the fluid supply pump.

  In addition, according to the lipid membrane manufacturing apparatus according to the present embodiment, the fluid 15 is present at the tip 2a ejected by the lipid fluid ejection nozzle 2 during standby of the ejection operation, and the tip 2a is blocked by the fluid 15. it can. For this reason, the lipid solution 16 does not come into contact with the solution around the lipid solution discharge nozzle 2, and the surrounding aqueous solution does not flow back to the nozzle, so that deterioration of the lipid membrane due to emulsification can be prevented. Further, the fluid left at the tip 2a of the lipid solution discharge nozzle 2 can prevent leakage of the lipid solution following the fluid.

  Moreover, in the lipid membrane production apparatus according to the present embodiment, the fluid is preferably an inert fluid that does not react with the lipid liquid and the aqueous solution. By using the inert fluid in this manner, the fluid does not react with the lipid solution or the solution around the discharge device, so that emulsification can be prevented and a stable lipid bilayer membrane can be generated.

(Other embodiments)
Although the present invention has been described according to the above-described embodiments, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, in the present embodiment, the lipid liquid supply pump and the fluid supply pump have been described as supply means. However, the present invention is not limited to this as long as the lipid liquid and the fluid can be alternately supplied.

  As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

  The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to the following examples. In order to confirm the effect of the lipid membrane production apparatus according to the embodiment of the present invention, the generation of the lipid bilayer membrane is performed when the conventional lipid membrane production apparatus is used and when the lipid membrane production apparatus shown in FIG. 1 is used. Went.

(Conventional example)
A lipid bilayer was produced using a conventional lipid membrane preparation apparatus.

  Specifically, 1 μl of lipid solution was discharged into a through-hole having a diameter of 400 μm using a 5% monoolein lipid solution dissolved in decane. And the change of the lipid membrane was observed.

(result)
The results are shown in FIG. FIG. 4 is a photograph taken with an optical microscope, and the through-hole diameter is 400 μm. FIG. 4 shows a state immediately after discharging the lipid solution, and the lipid film contains a large amount of emulsion. In addition, it took about 3 hours to convert from a lipid multilayer membrane to a lipid bilayer membrane.

(Example)
A lipid bilayer membrane was produced using the lipid membrane production apparatus shown in FIG.

  Specifically, air and 5% monoolein lipid solution dissolved in decane were alternately fed into a Teflon tube at a ratio of 2 to 1, and 0.5 μl of lipid solution was discharged into a through-hole having a diameter of 400 μm. And the change of the lipid membrane was observed.

(result)
The results are shown in FIG. FIG. 5 is a photograph taken with an optical microscope, and the through-hole diameter is 400 μm.

  FIG. 5 (a) shows a state immediately after the lipid liquid is discharged, FIG. 5 (b) shows 30 seconds after the lipid liquid is discharged, and FIG. 5 (c) shows a state after the lipid liquid is discharged. After 32 seconds, FIG. 5 (d) shows a state 35 seconds after the lipid solution is discharged. As shown in FIG. 5 (a), a lipid membrane containing no emulsion was produced. Furthermore, no leakage of lipid liquid was observed from the lipid liquid discharge nozzle 2 during standby. Then, in FIG. 5 (b), the film is converted into a rainbow-colored lipid multilayer film, and in FIG. 5 (c), the conversion from the lipid multilayer film to the lipid bilayer starts from the upper right, and in FIG. A bilayer spread throughout the iridescent membrane.

  Therefore, it can be seen that the lipid membrane production apparatus according to the present embodiment can produce a lipid liquid that does not contain an emulsion, and can produce a lipid bilayer membrane in 35 seconds after the lipid liquid is discharged. It was. It was also found that the leakage of the lipid solution from the lipid solution discharge nozzle 2 can be prevented.

It is a block diagram of the configuration of a lipid membrane production apparatus according to the present embodiment. It is an enlarged view of the tube in FIG. It is an enlarged view of the nozzle for lipid liquid discharge in FIG. It is an optical microscope photograph which shows the production | generation of the lipid bilayer membrane in a prior art example. It is an optical micrograph which shows the production | generation of the lipid bilayer in an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Lipid film 2 ... Lipid liquid discharge nozzle 2a ... Tip 3 ... Sample liquid storage part 4 ... Reference liquid storage part 5 ... Partition wall 6, 7 ... Electrode 8 ... Measuring device 9 ... Recorder 11 ... Lipid liquid supply pump 12 ... Fluid supply pump 13 ... Merging section 14 ... Tube 15 ... Fluid 16 ... Lipid liquid 20 ... Reference liquid flow port 21 ... Sample liquid flow port

Claims (4)

A first aqueous solution container, a second aqueous solution container, a partition wall located between the first aqueous solution container and the second aqueous solution container, and having a through hole; A lipid membrane production apparatus comprising a discharge means for discharging into a hole,
A lipid membrane production apparatus comprising supply means for alternately supplying the lipid liquid and fluid to the discharge means.   The lipid membrane production apparatus according to claim 1, wherein the supply means is a pump for supplying the lipid liquid and a pump for supplying the fluid.   3. The lipid membrane production apparatus according to claim 1, wherein the fluid is present at a distal end of the ejection unit during standby of the ejection operation. 4. The lipid film production apparatus according to any one of claims 1 to 3, wherein the fluid is an inert fluid that does not react with the lipid solution and the aqueous solution.