CN111545145A - A temperature-controlled fiber-integrated micro-reaction chamber - Google Patents

Abstract

The invention provides a temperature-controllable fiber integrated micro reaction cavity. The method is characterized in that: the device consists of a multi-core holed fiber, a wide-spectrum light source, a liquid absorption waveband light source, a spectrometer, an injection pump, a circulator, a single-mode fiber and a water tank containing absorption matching liquid. The air holes of the optical fiber with the holes can be used as microfluidic channels, the micro fluid in the holes is heated by using a photo-thermal effect, the temperature of the micro fluid is fed back through the fiber bragg grating, the power of output laser is controlled, and therefore the temperature of the micro fluid in the holes is controlled. The invention can be used as a micro-liquid reaction chamber, has the advantages of simple structure, accurate temperature control, flexible operation and the like, and is particularly suitable for biochemical reaction sensitive to temperature.

Description

A temperature-controlled fiber-integrated micro-reaction chamber

(1) Technical field

The invention relates to a temperature-controllable fiber-integrated micro-reaction chamber, which belongs to the technical field of micro-flow control.

(2) Background technology

Microfluidic control system refers to the use of precision machining technology to integrate various functional units such as microchannels, micropumps, microvalves, microreactors, microsensors, and microdetectors on a tiny chip. It is a micro-analysis system that completes the functions of sample preparation, mixing, reaction, separation, detection, and biochemical analysis in the field of biology and chemistry. The microfluidic system has many unique properties such as extremely fast analysis speed, minimal reagent consumption, volume integration, function integration, simple operation, and low price. It can be widely used in biomedicine, analytical chemistry, drug screening, environmental monitoring and other fields.

Compared with macroscopic reactions, microreactors have at least the following advantages:

(1) In micron-scale microreactors, the diffusion distance required for the solute of the trace liquid is short, the mass transfer is faster, and the mixing is rapid and uniform.

(2) Since the scale of the microreactor is only in the order of microns, it brings a large specific surface area to the reactor. This makes the reactor have a large heat exchange area, and the thermal conductivity of the microreactor is an order of magnitude higher than that of the conventional reactor. Relatively speaking, it is easier and more accurate to control the reaction temperature and reaction time.

(3) The overall volume of the microreactor is small, and the amount of reagents required for the reaction in the microreactor is small. For many reactions that require the use of toxic and harmful reagents, it provides a more environmentally friendly approach; for many reactions that require expensive reagents, it reduces the waste of reagents and saves costs.

Traditional microreactors are mostly based on photolithography, etching and mechanical micromachining methods on materials such as silicon wafers, quartz, PMMA (polymethyl methacrylate) and PDMS (polydimethylsiloxane) preparation. The equipment used in these preparation methods is expensive and the process is complicated, which not only brings about an increase in cost, but also makes it difficult to achieve mass production with high yield.

(3) Contents of the invention

The purpose of the present invention is to provide a fiber-integrated micro-reaction chamber with controllable temperature, convenient and flexible operation.

The object of the present invention is achieved in this way:

A temperature-controlled fiber-integrated micro-reaction chamber. It consists of a multi-core holey fiber 1, a broad-spectrum light source 2a, a pump light source 2b, a fiber wavelength division multiplexer 8, a spectrometer 3, a syringe pump 4, an optical fiber circulator 5, a standard single-mode fiber 6 and a matching liquid containing light absorption The sink consists of 7. In the system: (1) Microholes 1-5 are prepared on the multi-core holey fiber 1, which are the inlet and outlet of the trace liquid 9; (2) The output light of the broad-spectrum light source 2a and the pump light source 2b is determined by a standard single The mode optical fiber 6 is led out, and after passing through the optical fiber wavelength division multiplexer 8, it is injected into the multiple cores of the holey optical fiber 1 together; (3) the syringe pump 4 is used to control the inflow and outflow of the trace liquid 9 in the optical fiber microporous cavity; (4) The pump light transmitted in the suspension core is absorbed by the liquid in the cavity and converted into internal energy, and the reaction temperature of the liquid in the cavity can be adjusted by controlling the input power; (5) The fiber embedded in the annular cladding Bragg gratings 1-7 are prepared on the core for temperature monitoring in the reaction chamber; (6) a water tank 7 containing light-absorbing matching liquid is connected to the end of the optical fiber for absorbing transmitted light and eliminating end-face reflection.

The present invention adopts a multi-core holey fiber 1, which consists of an air hole 1-1 in the middle, an annular cladding 1-2, a fiber core 1-4 embedded in the annular cladding, and a suspension core suspended in the air hole 1-3 compositions.

Optionally, the suspension cores 1-3 may be one, or multiple, or may be annular cores.

The air hole of the multi-core holey optical fiber is used as a reaction microcavity of trace liquid, and two or more micropores 1-5 are prepared on the cavity wall, which are used as the inlet and outlet channels of trace liquid.

The wavelength band of the pump light source 2b is the strong absorption band of the liquid in the cavity, and the broadband light source 2a is the ASE light source of the C+L band.

There are two ways of coupling the incident light to the multi-core holey fiber: (1) After the arc collapse of one end of the multi-core holey fiber, it is welded to the standard single-mode fiber, and then tapered to couple the incident light into the hole. Each core; (2) One end of the multi-core holey fiber is arc-collapsed and welded to the standard single-mode fiber, and then heated at the welding point, using the thermal diffusion coupling method, so that the incident light is in the thermal diffusion area 1-6 coupled into each fiber core.

The present invention can realize the biochemical reaction of trace substances, and has the following obvious advantages compared with the existing trace reactors:

(1) The present invention highly integrates these reaction devices into an optical fiber, which has the characteristics of high operational flexibility and easy integration, and the optical fiber preparation process is quite mature, the preparation cost is low, and the production of optical fibers is satisfied that a large number of optical fibers can be prepared at one time. requirements, the specifications have good consistency. This will be very beneficial to the mass production of micro-reaction cavity devices.

(2) The present invention adopts the heating method of photothermal conversion, realizes non-contact heating of trace reaction reagents, and can precisely control the temperature by the magnitude of the input optical power, thereby controlling the process of the entire biochemical reaction.

(3) The present invention adopts Bragg grating, which has good sensitivity to temperature, so it can monitor the reaction temperature of the reaction chamber with high precision and give feedback, which is convenient for monitoring the progress of the entire biochemical reaction.

To sum up the above, the present invention is suitable for the mixed reaction of trace liquids, and is especially suitable for the experimental requirements with strict requirements on the reaction temperature.

(4) Description of drawings

Fig. 1 is the end face structure of several kinds of special optical fibers that can be used as described in the embodiment.

Figure 2 is a schematic diagram of the system structure of a temperature-controllable fiber-integrated micro-reaction chamber.

Figure 3 is a schematic diagram of the principle of a temperature-controlled fiber-integrated micro-reaction chamber.

FIG. 4 is a flow diagram of the PCR described in Example 2. FIG.

(5) Specific implementation methods

The present invention will be further described below in conjunction with the specific drawings and embodiments, but the protection scope of the present invention should not be limited by this.

Example 1:

Fig. 1 shows several multi-core holey microstructured optical fibers 1 that can be used in the present invention, the optical fiber comprising an air hole 1-1 in the middle, an annular cladding 1-2, a suspended core 1-3 exposed in the air hole and Core 1-4 embedded in annular cladding 1-2. The air hole 1-1 is used as the reaction cavity for the trace liquid; the suspension core 1-3 is used to transmit the laser 2-2 of the characteristic absorption band of the liquid in the cavity, and the reaction temperature in the reaction cavity is controlled by changing the input size of the laser energy in this band. ; Bragg gratings are prepared on the cores 1-4 for monitoring and feedback of the temperature in the reaction chamber. The fiber core 1-4 may be one (as shown in FIG. 1a ), or multiple (as shown in FIG. 1-3a and 1-3b in FIG. 1b ), or may be a ring-shaped fiber core (as shown in FIG. 1c ).

In this embodiment, the light beam is input into the multi-core holey fiber by means of thermal diffusion coupling. The preparation method of the micro-reaction chamber is as follows:

(1) Take a section of multi-core holey optical fiber 1, strip off the coating layer and cut to prepare a flat end face;

(2) Use arc heating to collapse both ends of the multi-core holey fiber 1 until the air holes 1-1 at both ends are completely fused into a solid;

(3) The standard single-mode optical fiber 6 and the suspension cores 1-3 on the collapsed end face of the multi-core holey optical fiber 1 are core-welded.

(4) The thermal diffusion coupling method is adopted at the solder joint, and the local heating to 1500°C makes the dopant in the core diffuse to form the thermal diffusion coupling region 1-6, so that the input light 2-1 containing the broad-spectrum laser Coupling into cores 1-4 embedded in the cladding.

(5) Bragg gratings 1-7 are written on the cores 1-4 embedded in the cladding using a fiber grating preparation device.

(6) Using a femtosecond laser, without destroying the cores 1-4 embedded in the cladding, the inlets and outlets 1-5 of the microfluidics are prepared.

FIG. 2 is a schematic diagram of the system structure of a temperature-controllable fiber-integrated micro-reaction chamber, and FIG. 3 is a schematic diagram of the principle of the micro-reaction chamber. The broad-spectrum light source 2a is the signal source used for the temperature-sensitive gratings 1-8, and the output light of the pump light source 2b is the characteristic wavelength band absorbed by the reaction liquid 9 in the cavity, and its wavelength is λ _a (taking the aqueous solution as an example, λ _a can be is 1480 nm) for temperature modulation of the reaction chamber. The light beams 2-1 of the two light sources 2a and 2b are led out by the standard single-mode fiber 6, and are coupled into the multi-core holey fiber 1 through the fiber wavelength division multiplexer 8 and the circulator 5. The light λ _b 2-2 reflected back by the Bragg fiber grating embedded in the cladding is output to the spectrometer 3 through the circulator 5, and a one-to-one correspondence with the temperature is established according to the position of λ _b , so as to achieve the reaction cavity. Internal temperature monitoring feedback function. The other end of the multi-core holey optical fiber is provided with a water tank 7 for absorbing the matching liquid, which is used to absorb the transmitted light and reduce the reflection on the end face. The syringe pump 4 is used for the injection and output of the micro-reaction solution 9 .

Example 2:

The following takes DNA polymerase chain reaction as an example to introduce the application of the micro-liquid reaction chamber of the present invention as PCR (as shown in FIG. 4 ).

Step 1: Prepare reaction materials, 200umol/L of 4 dNTP mixtures, 10-100pmol of primers, 0.1-2μg of template DNA, 2.5μg of Taq DNA polymerase, 1.5mmol/L of Mg ²⁺ ;

Step 2: use the syringe pump 4 to inject the raw material to be reacted into the multi-core holey fiber microcavity;

Step 3: Denaturation. Turn on the laser light sources 2a and 2b, adjust the power of the pump light source 2b, and observe the temperature in the cavity fed back by the fiber grating 1-7, so that the temperature in the cavity reaches 94°C and lasts for 30s. The high temperature causes the double-stranded DNA to dissociate and form single chain;

Step 4: Annealing. Adjust the power of the liquid characteristic absorption band light source 2b, adjust the temperature to 60-65°C for 30s, and at a low temperature, the primers are combined with the complementary region of the template DNA;

Step 5: Extend. Adjust the temperature in the chamber to 70～75℃, and keep it for 30～60s, the DNA polymerase catalyzes the DNA chain extension reaction with the primer as the starting point;

Step 6: Repeat steps 2 to 4 until the required amount of DNA is reached, and then use the syringe pump 4 to pump out the reaction product.

Claims (6)

1. The utility model provides a controllable fibre integrated micro reaction chamber of temperature which characterized by: the device consists of a multi-core holey fiber, a wide-spectrum light source, a pumping light source, a fiber wavelength division multiplexer, a spectrometer, an injection pump, a fiber circulator, a standard single-mode fiber and a water tank containing light absorption matching fluid. In the system: (1) micropores are formed on the multi-core holey fiber and are used as an inlet and an outlet of a trace amount of liquid; (2) the output light of the wide-spectrum light source and the pump light source is led out by a standard single-mode optical fiber and is injected into a plurality of fiber cores of the optical fiber with holes together after passing through an optical fiber wavelength division multiplexer; (3) the injection pump is used for controlling the inflow and outflow of trace liquid in the optical fiber micro-cavity; (4) the pumping light transmitted in the suspension core is absorbed by the liquid in the cavity and converted into internal energy, and the reaction temperature of the liquid in the cavity can be adjusted by controlling the input power; (5) a Bragg grating is prepared on the fiber core embedded in the annular cladding and used for monitoring the temperature in the reaction cavity; (6) the tail end of the optical fiber is connected with a water tank containing light absorption matching liquid for absorbing transmitted light and eliminating end face reflection.

2. The temperature-controllable fiber-integrated micro-reaction chamber as claimed in claim 1, wherein: the multi-core holey fiber is adopted and consists of a middle air hole, an annular cladding, a fiber core embedded in the annular cladding and a suspension core suspended in the air hole.

3. The multicore holey fiber of claim 1 and claim 2, wherein: the suspension core can be one, a plurality of or annular fiber cores.

4. The multicore holey fiber of claim 1 and claim 2, wherein: the air holes of the multi-core holey fiber are used as a reaction micro-cavity of the trace liquid, and two or more micro-holes are prepared on the cavity wall of the multi-core holey fiber and used as inlet and outlet channels of the trace liquid.

5. The temperature-controllable fiber-integrated micro-reaction chamber as claimed in claim 1, wherein: the wave band of the pump light source is a strong absorption wave band of liquid in the cavity.

6. The temperature-controllable fiber-integrated micro-reaction chamber as claimed in claim 1, wherein: the coupling mode of the incident light to the multi-core holey fiber can be two types: (1) one end of the multicore perforated fiber is welded with the standard single-mode fiber after arc collapse, and then tapered, so that incident light is coupled into each fiber core; (2) one end of the multicore holey fiber is welded with the standard single-mode fiber after arc collapse, then the welding point is heated, and incident light is coupled into each fiber core in a thermal diffusion coupling mode.

Images