KR20090088758A - Microfluidic system for practical running with a nano-gap sensor and method for preparing the same - Google Patents

Abstract

A microfluidic system is provided to operate it through simple manipulation and to realize miniaturization by grafting a nano gap sensor with a microfluidic chip and to perform all process in a short reaction time by suing only nanogram of samples. A microfluidic system for practical running of a nano gap device comprises a nano gap sensor where an acceptor modified on the surface of a nano gap electrode; a sample inlet for introducing the solution for analyzing; a micro channel which is connected to the sample inlet and provides the channel of the solution introduced through the sample inlet; and a microfluidic chip formed with a sample outlet arranged in the end of the micro channel.

Description

Microfluidic system for practical driving of nanogap devices and its manufacturing method {MICROFLUIDIC SYSTEM FOR PRACTICAL RUNNING WITH A NANO-GAP SENSOR AND METHOD FOR PREPARING THE SAME}

The present invention relates to a microfluidic system and a method of manufacturing the same for the practical driving of the nanogap device. More specifically, the present invention is a microfluidic device in which a nanogap sensor is combined with a microfluidic chip to drive a simple analysis to realize practical analysis using a nanogap sensor and realize its value as a small analysis device. It relates to a dick system and a method of manufacturing the same.

Nanogap devices are a field of biosensors that selectively respond to analytes and generate signals by detecting analytes and converting them into optical or electrical signals through biological recognition processes using biological receptors suitable for analytical purposes. It is a kind of biosensor. The detectable materials include biomaterials such as proteins, DNA, bio secretions, environmental substances such as heavy metals, pesticides associated with foods, and the like, and can be used to analyze various chemicals. The nanogap device uses nanogap electrodes with a spacing of about 1-100 nm, and measures and applies characteristics of nanotubes, nanoparticles, nanowires, and other materials having nanometer size such as proteins and DNA. The field of development is rapidly developing.

Nanogap devices use biological receptors (e.g. proteins, DNA, cells, biological tissues, etc.) that are responsible for recognizing targets and generating signals, through reaction with substrates that specifically bind to them. Electrochemical signals are obtained by optical and electrochemical methods.

The advantage of such a biosensor is that it can quickly and accurately analyze the target material by reacting quickly to the analyte. In other words, simplicity, rapidity, and sensitivity of measurement are unique advantages of biosensors.

However, in order for nanogap devices to be used for analytical purposes as a new technology field, it is necessary to satisfy the advantages of the above-described biosensors and solve various technical problems. In particular, the reaction time required to modify the biological receptor on the surface and the conjugation time required for the biological receptor to recognize and respond to the target are the inhibitors in the speed of analysis.

In the mid-1990s, a lab-on-a-chip reported based on soft lithography and microelectromechanical system technology, a semiconductor process, regulates the flow of a sample. Dilutions, mixing, reactions, separations, quantifications, etc. are ideal models of the integrated analytical device, which is presented to be able to continuously perform on one small chip. Microfluidic systems are the areas involved in the fabrication of microchannel patterns and microfluidic flow control in order for the lab-on-a-chip to fully function.

Microfluidic chips were initially made of glass or quartz, and recently, based on the advantages of microstructure reproducibility, optical properties, environmental and biocompatibility, PDMS (poly (dimethylsiloxane)) and PMMA (poly (methyl methacrylate)) Polymer materials such as polycarbonate (PC), polyethylene (tereph thalate) (PET), etc. are in the spotlight, and various developments of microfluidic chips have been made using these materials.

It is an object of the present invention to provide a microfluidic system and a method of manufacturing the same for practical driving of a nanogap device. More specifically, it is an object of the present invention to provide a microfluidic system and a method of manufacturing the same, which can be driven and reduced in size by incorporating a nanogap sensor into a microfluidic chip.

Another object of the present invention is to combine a microfluidic chip with a nanogap sensor in order to maximize the convergence of features such as rapidity, sensitivity, accuracy, etc. to provide a practical microfluidic system and a method of manufacturing the same that combines the advantages thereof. will be.

It is still another object of the present invention to fabricate and incorporate a microfluidic chip, which is characteristic of nanogap sensors, to simply control the fluid flow inside the microchannels to easily formulate the nanogap sensor surface and easily perform microfluidics. It is to provide a dick system and a method of manufacturing the same.

Another object of the present invention is to replace the analysis method of bulk nanogap devices, formulate the nanogap sensor surface by physical / chemical method, and combine it with microfluidic chip to use only nanogram-level samples. The present invention provides a microfluidic system and a method of manufacturing the same, in which all processes can be performed / completed within a short reaction time.

According to a preferred embodiment of the invention, the receptor is connected to the sample inlet, the sample inlet for introducing a nano-gap sensor formulated on the surface of the nano-gap electrode, the solution to be analyzed, the sample inlet, and introduced through the sample inlet And a microfluidic chip having a microchannel for providing a movement path of a solution, and a sample outlet disposed at an end of the microchannel, wherein the nanogap sensor is positioned on the microfluidic chip, and the microfluidic A microfluidic system is provided for practical driving of a nanogap device, wherein a sample traveling through a microchannel of a chip is placed in contact with a modified receptor on the nanogap sensor.

According to another preferred embodiment of the present invention, the sample inlet is provided with a plurality of three or more, one of which is the inlet of the cleaning liquid, the other of the sample solution containing a substrate that specifically binds to the receptor A microfluidic system for practical driving of a nanogap device is provided, which is an inlet and the other is an inlet of a signal generator that specifically binds to the substrate.

According to another preferred embodiment of the present invention, the sample inlet is provided with a plurality of four or more, one of which is the inlet of the cleaning solution for cleaning before supplying the sample solution, the other is specific to the receptor The inlet of the sample solution containing the substrate to bind to the substrate, the other is the inlet of the signal generator that specifically binds to the substrate, the other is the inlet of the cleaning solution for the final cleaning after supplying the sample solution, A microfluidic system for practical driving of a nanogap device is provided, characterized in that.

According to a more preferred embodiment of the present invention, there is provided a microfluidic system for practical driving of a nanogap element, to each of the sample inlets, to which a programmed flow control multipump for supplying a solution in a constant pattern is connected. .

According to another preferred embodiment of the present invention, a micro inlet for introducing a solution to be analyzed on the surface of the substrate, and a micro-channel which is connected to the sample inlet, the passage of the solution introduced through the sample inlet A first step of embossing a channel and a sample outlet disposed at an end of the microchannel; A second step of preparing a microfluidic compound by injecting and solidifying a polymer into the relief mold and releasing the polymer; A third step of surface treating the surface of the microfluidic chip using plasma discharge; A method of manufacturing a microfluidic system is provided, which comprises a fourth step in which a receptor bonds a nanogap sensor modified on the surface of a nanogap electrode to the top of the microfluidic chip.

The microfluidic system according to the present invention provides the following effects.

First, the high cost of sample consumption during analysis and pretreatment is greatly reduced.

Second, the reaction time required for surface modification of biological receptors and detection of target substances is greatly reduced.

Third, environmental emissions can be reduced because chemical emissions are at the micro to nano level.

Fourth, if the number of microchannel patterns is sufficiently increased, any complicated preprocessing and analysis process can be performed simply and sequentially.

Fifth, if each microchannel is operated by using a programmable flow control multi-pump, it is possible to construct a simple, labor-consuming, modular preprocessing automation system.

Sixth, by applying well-known microfluidic chip fabrication technology such as semiconductor process to nanogap devices, it can be used to build a biosensor system capable of simple and rapid measurement. In addition, by using a low-cost material such as a polymer material, it is possible to bring down the cost in manufacturing in the system for pretreatment and analysis proposed in the present invention.

The microfluidic system for practical driving of the nanogap device according to the present invention comprises a) a nanogap sensor whose receptor is modified on the surface of the nanogap electrode, a sample inlet for introducing a solution to be analyzed, and b) the sample. A microfluidic chip connected to an inlet, said microfluidic chip having a microchannel for providing a movement passage of the solution introduced through said sample inlet, and a sample outlet disposed at the end of said microchannel, wherein said microfluidic The nanogap sensor is located on top of the chip and a sample traveling through the microchannels of the microfluidic chip is placed in contact with the receptors formulated in the nanogap sensor.

With reference to the accompanying drawings, a microfluidic system for practical driving of the nanogap device according to the present invention will be described in detail with respect to configuration and operation.

1 shows a microfluidic chip engraved with a microchannel pattern through a semiconductor process such as lithography, and FIG. 2 is a schematic pattern of a microfluidic system obtained by bonding a nanogap sensor onto the microfluidic chip. Shows. Through the four sample inlets illustrated in FIG. 1, air to dry an antigen-labeled nano gold particle, an antibody, a buffer solution and a nanogap sensor may be injected.

First, the configuration and operation of the nanogap sensor are already well known, and for more detailed description thereof, refer to Korean Patent No. 762,258 owned by the present applicant. The contents described in Korean Patent No. 762,258 are referred to for understanding the present invention.

The present invention is to implement a nanogap-microfluidic chip system to perform a surface modification process and a practically simple analysis process to impart the functionality as a sensor to the nanogap device. In the case of microfluidic chips, it is easy to reproduce microstructures when using materials such as polymers. Since the size of microstructures is generally micro level, each microchannel is assigned to each microchannel. If you control it with a programmable flow control multipump, you can simply run the analysis on a single nanogap-microfluidic chip.

FIG. 3 shows a uniform microchannel pattern of a nanogap-microfluidic system, and FIG. 4 accurately matches the channels of the nanogap device and the microfluidic using the xyz stage. FIG. 5 is a nanogap-microfluidic chip manufactured by aligning microchannels of a microfluidic and nanogap elements to be exactly aligned and then bonding them. 6 is a fluorescent solution (analyte substitute) is injected into the microchannel by the flow control pump. The analytical target solution being injected into the nanogap-microfluidic system passes through the nanogap device region through flow control, and FIGS. 7 (a), 7 (b) and 7 (c) show the analyte target (fluorescent material). ) Is observed at 0.1s intervals.

 <Example>

Example 1 Fabrication of Nanogap-Micro Fluidic System.

During the process of fabricating the polymer microfluidic chip, 55 minutes in pyrania solution (sulfuric acid: hydrogen peroxide = 3: 1) was used to remove impurities on the surface of slide glass (Corning, Switzerland) of 75 × 25 cm. After soaking, the solution was removed from the piranha solution. After spin-coating SU-50 (Microchem, USA), a photoresist on the washed slide glass at 3000 rpm, the soft baking process was performed at 65 ° C. and 95 ° C. for 5 minutes and 15 minutes, respectively. Using a mask engraved with a microchannel pattern as shown in FIG. 1, the UV alignment device is exposed at an intensity of 20 mJ / cm ² for 15 seconds. After the post-exposure bake process, such as the soft bake process, it was developed using a SU-8 developer (Microchem; USA). The developed slide glass mold is washed with distilled water and blown with air. Pour the PDMS (PDMS: hardener = 10: 1) solution on the mold and dry in an oven at 70 ℃ and release. The silicon wafer with the PDMS and the nanogap element with the microchannel pattern is exposed to the corona discharger for 5 minutes and then bonded. Since the nanogap-mounted device and the microfluidic chip channel are about the size of a micrometer, the bonding process was performed after aligning using the xyz stage and the earned microscope. 3 shows a PDMS channel arranged to exactly match the nanogap device region. FIG. 4 shows a nanogap microfluidic chip fabricated through a final bonding process after the nanogap device and the microfluidic chip are exactly aligned.

Example 2: Nanogap-Micro Fluidic System Fabrication.

Four Teflon tubes with an outer diameter of 1.2 mm were tubed from each other in each of four sample inlets having a diameter of 1 mm in the microfluidic chip. 5 shows a compact analysis system in which a nanogap-microfluidic chip and a flow control pump are connected through a Teflon tube. The flow control pump was used to adjust the pressure of the fluid flowing in each channel. 6 shows a nanogap-microfluidic system into which a fluorescent solution is being injected. 7 (a), 7 (b) and 7 (c) show fluorescence images when a desired sample of four samples is injected for 5 seconds in the direction of the nanogap device. Each injection scene is observed in 0.1 second increments. 10 mM rhodamine B was used to monitor the flow of the fluid sequentially so that the desired solution passed through the nanogap sensor region.

The results of Examples 1 and 2 indicate that a simple and quick analysis is possible even with a small amount of sample. More specifically, the introduction of a sample at the micro level through a microchannel indicates that a simple and efficient analysis can be performed.

Meanwhile, the microfluidic system illustrated in FIG. 1 and the like describes an example in which four sample inlets are provided. Here, any one of four is the inlet of the cleaning solution for cleaning before supplying the sample solution, the other is the inlet of the sample solution containing the substrate specifically binding to the receptor, the other is specific to the substrate It is preferable that the inlet of the signal generating material to be coupled to each other, and the other is the inlet of the cleaning solution for the final cleaning after supplying the sample solution. As an example of a signal generator that specifically binds to a substrate, an antibody, a protein, or the like derivatized by an electrical or optical signal generator may be used. The sample inlet may be modified in various ways depending on the type of material to be analyzed. For example, three sample inlets may be provided. At this time, one of the three sample inlet is the inlet of the cleaning solution, the other is the inlet of the sample solution containing the substrate specifically binding to the receptor, the other is the signal generation that specifically binds to the substrate It will be used as the inlet of the material.

1 is a photograph of a microfluidic chip engraved with a microchannel pattern through a semiconductor process such as lithography.

2 is a conceptual diagram of a design of a microfluidic system obtained by bonding a nanogap sensor on the microfluidic chip.

3 is a diagram showing an arrangement of a nanogap sensor and a microfluidic chip in a microfluidic system according to the present invention.

Figure 4 shows the final microfluidic system fabricated after the bonding process of the nanogap device and the microfluidic chip.

FIG. 5 is a photograph of a scene in which a Teflon tube connected to a flow control pump is connected to a nanogap-microfluidic system.

6 is a photograph of a scene in which the actual labeling material is injected through the microfluidic system according to the present invention.

7 (a), 7 (b), and 7 (c) are photographs observed at 0.1 second intervals when the fluid inside the microchannel is controlled by a flow control pump. This is an illustration of the flow of injected fluid.

Claims (5)

A nanogap sensor with a receptor formulated on the surface of the nanogap electrode, A micro-channel having a sample inlet for introducing a solution to be analyzed, a micro channel connected to the sample inlet and providing a moving passage of the solution introduced through the sample inlet, and a sample outlet disposed at the end of the micro channel Contains fluidic chips, The nanogap sensor is positioned on top of the microfluidic chip, and a sample moving through the microchannel of the microfluidic chip is placed in contact with a receptor modified in the nanogap sensor. For microfluidic systems. According to claim 1, wherein the sample inlet is provided with a plurality of three or more, one of which is the inlet of the cleaning liquid, the other is the inlet of the sample solution containing the substrate specifically binding to the receptor, the other One is a microfluidic system for practical driving of the nano-gap device, characterized in that the inlet of the signal generating material that specifically binds to the substrate. According to claim 1, wherein the sample inlet is provided with a plurality of four or more, one of which is the inlet of the cleaning solution for cleaning before supplying the sample solution, the other is a substrate that specifically binds to the receptor Inlet of the sample solution containing, the other is the inlet of the signal generating material specifically binding to the substrate, the other is the inlet of the cleaning solution for the final cleaning after supplying the sample solution, characterized in that Microfluidic system for practical driving of nanogap devices. The microfluidic system of claim 2 or 3, wherein each of the sample inlets is connected to a programmed flow control multipump for supplying a solution in a constant pattern. On the surface of the substrate, a sample inlet for introducing a solution to be analyzed, a microchannel connected to the sample inlet and providing a movement passage of the solution introduced through the sample inlet, and disposed at the end of the microchannel. A first step of embossing the sample outlet; A second step of preparing a microfluidic compound by injecting and solidifying a polymer into the relief mold and releasing the polymer;  A third step of surface treating the surface of the microfluidic chip using plasma discharge; And a fourth step in which the receptor bonds a nanogap sensor modified on the surface of the nanogap electrode to the top of the microfluidic chip.

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