KR20210057476A - Method and apparatus for detecting target dna based on current using field effect transistor - Google Patents

Abstract

Disclosed are a method and apparatus for detecting a target DNA using a field effect transistor (FET). The apparatus for detecting the target DNA using an FET comprises: the FET which includes a gate electrode connected to a reference power supply, a drain electrode connected to a current detection unit, and a source electrode connected to the grounding; a sample introduction unit engaged with the gate electrode as a base DNA is previously fixed; the current detection unit which detects a drain current of the FET; and a reading unit which detects the target DNA by comparing the drain current with a reference current. Accordingly, the present invention is able to precisely detect a target DNA.

Description

A method and apparatus for detecting target DNA using a field effect transistor TECHNICAL FIELD

The present invention relates to a method and apparatus for detecting target DNA using a field effect transistor, and more particularly, a method for detecting a target DNA by fixing a base DNA to a gate electrode of a field effect transistor and measuring a change in drain current, and It relates to the device.

Recently, as biotechnology has been widely developed, technologies for detecting and contrasting genetic materials are being used in various fields. For example, nucleic acids (such as DNA or RNA) of bacteria or viruses can be detected to analyze the cause of diseases caused by viruses or pathogens. In addition, DNA detection technologies are being used in various fields, such as detecting genetic diseases in the human body or comparing DNA collected at a crime scene with DNA of a specific person.

DNA (deoxyribonucleic acid) is a nucleic acid containing deoxyribose, which is the genetic material of almost all living things except for viruses and others. For this reason, a technology for detecting a target DNA is used as a representative technology for detecting a genetic material.

In order to detect the target DNA, a pretreatment process for obtaining pure DNA and a process of amplifying DNA using a polymerase chain reaction (PCR) are preceded. Through the PCR process, target DNA can be amplified hundreds of millions of times, making it possible to detect even trace amounts of target DNA.

In particular, recently, lab-on-a-chip (LOC), a device that enables research on semiconductor technology, nanotechnology, biotechnology, etc., on a small chip through miniaturization and integration has been introduced. In the case of lab-on-a-chip, all processes from sample pretreatment to transportation, control, separation, analysis, and detection can be performed on one chip at a time. Time can also be shortened.

An object of the present invention for solving the above problems is to provide a method and apparatus for detecting a target DNA using a field effect transistor.

One aspect of the present invention for achieving the above object provides a method of detecting a target DNA using a field effect transistor.

A method of detecting a target DNA using a field effect transistor, comprising: fixing a base DNA to a sample introduction portion; Introducing a sample to be detected into a sample introduction portion to which the base DNA is fixed; Measuring the drain current of the field effect transistor; Comparing the measured drain current with a reference current; And detecting the target DNA according to the comparison result.

After the step of introducing the base DNA into the sample introduction portion, the step of measuring a drain current of the field effect transistor and setting the measured drain current as a reference current may be further included.

Measuring the drain current may include supplying a voltage of the reference power to the gate electrode of the field effect transistor.

The reference power Vref may turn on the field effect transistor.

Another aspect of the present invention for achieving the above object is to provide an apparatus for detecting a target DNA using a field effect transistor.

An apparatus for detecting a target DNA using a field effect transistor (FET) includes: a field effect transistor including a gate electrode connected to a reference power source, a drain electrode connected to a current detector, and a source electrode connected to ground; A sample introduction part to which the base DNA was previously introduced and bonded to the gate electrode; A current detection unit for detecting a drain current of the field effect transistor, and a read unit for detecting a target DNA by comparing the drain current with a reference current.

The base DNA is a complementary DNA having a sequence complementary to the target DNA; And a primer that binds to one end of the target DNA.

The field effect transistor may include an active layer pattern disposed on one surface of a base layer on which a buffer layer is formed and including a channel region forming a channel and a drain region and a source region disposed on both sides of the channel region.

When using the method and apparatus for detecting target DNA using the field effect transistor according to the present invention as described above, it is possible to quickly and accurately detect target DNA having a specific nucleotide sequence.

In addition, it has the advantage of being able to detect target DNA at once even for various DNAs.

1 is a cross-sectional view showing a field effect transistor (FET) according to an embodiment of the present invention.
2 is a conceptual diagram of an apparatus for detecting a target DNA according to an embodiment of the present invention.
3 is a conceptual diagram showing a base DNA for detecting a target DNA according to an embodiment of the present invention.
4 is an exemplary diagram in which an apparatus for detecting target DNA according to an embodiment of the present invention is implemented as an array.
5 is a flowchart of a method of detecting a target DNA according to an embodiment of the present invention.

In the present invention, various modifications may be made and various embodiments may be provided, and specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention. In describing each drawing, similar reference numerals have been used for similar elements.

Terms such as first, second, A, and B may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. The term and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being "connected" or "connected" to another component, it is understood that it may be directly connected or connected to the other component, but other components may exist in the middle. It should be. On the other hand, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that there is no other component in the middle.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof does not preclude in advance.

Unless otherwise defined, all terms used herein including technical or scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in the present application. Does not.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view showing a field effect transistor (FET) according to an embodiment of the present invention.

Referring to FIG. 1, a field effect transistor (FET) 100 is disposed on one surface of the base layer 110 on which the buffer layer 120 is formed, and includes a channel region 132 and a channel region 132 forming a channel. The active layer pattern 130 including the first region 131 and the second region 133 disposed on both sides is spaced apart from the active layer pattern 130 by the first insulating layer 140 and overlaps the active layer pattern 202 The first and second regions 131 and 133 of the active layer pattern 130 are spaced apart from the active layer pattern 130 by the gate electrode 180, the first insulating layer 140, and the second insulating layer 150. It may include a first electrode 160 and a second electrode 170 respectively connected to each other.

One of the first region 131 and the second region 133 may be a source region, and the other may be a drain region. For example, if the first region 131 is a source region, the second region 133 may be a drain region. Conversely, if the first region 131 is a drain region, the second region 133 may be a source region. This may vary depending on the carrier type (eg, N type or P type) of the field effect transistor 100 and the direction of current.

In addition, in the present invention, the positions of the first electrode 160 and the second electrode 170 are not particularly limited, and this may be variously changed according to exemplary embodiments. For example, when the field effect transistor 100 is directly connected to another circuit device (eg, at least one other transistor and/or capacitor, etc.) through the first region 131, the first electrode 160 is omitted. Can be. Similarly, when the field effect transistor 100 is directly connected to another circuit device through the second region 133, the second electrode 170 may be omitted.

In addition, depending on the viewpoint, the first and/or second regions 131 and 133 are regarded as source and/or drain electrodes of the field effect transistor 100, and the first and/or second electrodes 160 , 170 may be regarded as wirings connected to one electrode of the field effect transistor 100 or electrodes of other circuit elements. Ion doping may be applied to the first region 131 and the second region 133 to form a p-type or n-type channel. In an embodiment of the present invention, it can be assumed that a p-type channel is formed.

The channel region 132, the first region 131, and the second region 133 may each include poly-Si (polysilicon). Further, the gate electrode 180 may have the same width as the length of the channel region 132, but is not limited thereto.

An outer surface of the gate electrode 180 may be formed so that one or more DNA samples may be introduced. For example, the surface of the gate electrode 180 may be made of a material selected from the group consisting of _{gold, SiO 2} , TiO ₂ , and Al ₂ O _3.

Hereinafter, for convenience of description, the first region 131 is assumed to be a drain region, the second region 133 is a source region, the first electrode 160 is a drain electrode, and the second electrode 170 is a source electrode. And explain.

2 is a conceptual diagram of an apparatus for detecting a target DNA according to an embodiment of the present invention. 3 is a conceptual diagram showing a base DNA for detecting a target DNA according to an embodiment of the present invention.

Referring to FIG. 2, an apparatus 1000 for detecting a target DNA may include a field effect transistor 100, a sample introduction unit 200, a current detection unit 210, and a reading unit 220.

The sample introduction part 200 may be mounted on the surface of the gate electrode 180 of the field effect transistor 100 through a thin film process, and the sample introduction part 200 specifically binds to the base DNA 20 to obtain a base DNA. A receiving material capable of fixing 20 to the surface of the gate electrode 180 may be included. The sample introduction part 200 may be specifically combined with the base DNA 20 to induce the field effect transistor 100 to form a channel.

Referring to FIG. 3, the base DNA 20 is a genetic material capable of performing complementary binding with the target DNA 30, and a primer 15 and a complementary DNA 10 of the target DNA 30 are used. Can include. The complementary DNA 10 may be a single strand capable of complementary bonding (eg, weak hydrogen bonding) with the target DNA 30. The primer 15 is a short gene sequence capable of being combined with one end of the target DNA 30 and may be combined with the target DNA 30 from the 3'end of the primer 15 to form a single strand. Thus, the base DNA 20 may be DNA in which some double strands are formed by complementary bonding of the complementary DNA 10 and the primer 15 to each other.

The target DNA 30 may be complementarily bound to the base DNA 20 (by DNA polymerase). Specifically, the primer 150 and the target DNA 30 included in the base DNA 20 may be connected to each other to form a single strand, and the single strand formed here may be complementarily combined with the complementary DNA 10 to form a double Strand 40 can be formed.

The base DNA 20 and the target DNA 30 described above have been described on the premise of DNA, but may be substituted or replaced with a material selected from RNA, PNA (Peptide Nucleic Acid), LNA (Locked Nucleic Acid), and hybrids thereof. .

Referring back to FIG. 2, the base DNA 20 may be fixed in advance to the sample introduction part 200 to be coupled to the gate electrode 180 of the field effect transistor 100.

The gate electrode 180 of the field effect transistor 100 may be connected to the reference power Vref, and the drain electrode 160 may be connected to the current detector 210. In addition, the source electrode 170 may include a virtual ground or a ground. The reference power Vref may supply a voltage according to the gate-on level of the field effect transistor 100 to the gate electrode 180. For example, the reference power supply vref may supply a low level voltage when the field effect transistor 100 is a p-type transistor, and may supply a high level voltage when the field effect transistor 100 is a p-type transistor.

The current detection unit 210 may detect the drain current of the field effect transistor 100 and provide the detected drain current to the read unit 220. The current detection unit 210 may include one or more resistance distribution circuits.

The reading unit 220 may compare the drain current provided from the current detection unit 210 with a reference current to display whether or not the target DNA is detected. In this case, the reference current may be set in advance in the current comparator 210 by the user.

The reading unit 220 according to FIG. 2 may include a microprocessing unit (MPU) or a processor. Here, the processor may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor in which methods according to embodiments of the present invention are performed.

Further, although not shown in the drawings, the device 1000 according to FIG. 2 may further include a memory and a storage device. Each of the memory and the storage device may be configured with at least one of a volatile storage medium and a nonvolatile storage medium. For example, the memory may be composed of at least one of read only memory (ROM) and random access memory (RAM). In addition, the device 1000 according to FIG. 2 may further include a transceiver, an input interface device, an output interface device, and a storage device that perform communication through a wireless network.

4 is an exemplary diagram in which an apparatus for detecting a target DNA according to an embodiment of the present invention is implemented as an array.

Referring to FIG. 4, an apparatus for detecting a target DNA includes a transistor array 110 including a plurality of field effect transistors and a plurality of current detection units 230 connected to respective drain electrodes included in the transistor array 110. ) Can be included.

The transistor array 110 may have a structure in which the field effect transistors 100 according to FIG. 1 are connected in parallel to each other. In this case, some of the field effect transistors may share the first drain electrode (and the drain region). For example, field effect transistors disposed in the same row may share the same first drain electrode with each other. As another expression, some of the field effects (for example, field effect transistors arranged in the same row) may have one first common drain region, and may include a first drain electrode connected to the common drain region. have.

In addition, field effect transistors disposed in the same column may share the same second drain electrode with each other. As another expression, some of the field effects (for example, field effect transistors arranged in the same row) may have one second common drain region, and may include a second drain electrode connected to the common drain region. have.

In addition, some or all of the field effect transistors included in the transistor array 110 may share the same source electrode. Source electrodes of a plurality of field effect transistors included in the transistor array 110 may be connected to virtual ground or ground (GND).

Each of the plurality of field effect transistors included in the transistor array 110 may include gate electrodes independent from each other. Accordingly, the sample introduction part 200 according to FIG. 2 may be coupled to each gate electrode.

The plurality of current detection units 230 may include a plurality of row current detection units and a plurality of column current detection units.

The first drain electrodes of the plurality of field effect transistors included in the transistor array 110 may be connected to the plurality of row current detectors. For example, field effect transistors disposed in a first row may be connected to a first row current detector, and field effect transistors disposed in a second row may be connected to a second row current detector.

In addition, the second drain electrodes of the plurality of field effect transistors included in the transistor array 110 may be connected to the plurality of column current detectors. For example, field effect transistors disposed in a first column may be connected to a first column current detector, and field effect transistors disposed in a tenth row may be connected to a second column current detector.

Accordingly, each of the plurality of column current detection units and the plurality of row current detection units may perform the same functions as the current detection unit 210 of FIG. 2. That is, each of the plurality of column current detection units and the plurality of row current detection units may detect drain currents of a plurality of field effect transistors arranged in row units and drain currents of a plurality of field effect transistors arranged in column units.

Further, although not shown in the drawing, it may include a readout unit 220 connected to the plurality of current detection units 230. The reading unit 220 may compare drain currents detected by the plurality of row current detection units with a reference current to specify a row current detection unit in which a drain current having a difference greater than or equal to a threshold value is detected. In addition, it is possible to specify the thermal current detection unit in which the drain current having a difference of more than a threshold value is detected by comparing the drain currents detected by the plurality of thermal current detection units with the reference current. Accordingly, the readout unit 220 can detect the target DNA introduced into the field effect transistor disposed in the specific row and column by combining the specified row current detection unit and the column current detection unit.

5 is a flowchart of a method of detecting a target DNA according to an embodiment of the present invention.

The method according to FIG. 5 may be performed by the apparatus for detecting the target DNA according to FIG. 2.

5, the step of fixing the base DNA to the sample introduction portion (S100); Introducing a sample to be detected into a sample introduction portion to which the base DNA is fixed (S110); Measuring the drain current of the field effect transistor (S120); Comparing the measured drain current with a reference current (S130); And detecting the target DNA according to the comparison result (S140).

After the step of fixing the base DNA to the sample introduction portion (S100), the step of measuring the drain current of the field effect transistor and setting the measured drain current as a reference current may be further included.

Measuring the drain current (S120) may include supplying a voltage of the reference power Vref to the gate electrode 180 of the field effect transistor. The reference power Vref may turn on the field effect transistor 100.

The step of detecting the target DNA according to the comparison result (S140) may include determining that the target DNA has been detected when the difference value between the reference current and the drain current as a result of the comparison is greater than or equal to a threshold value. For example, when a target DNA is included in a sample to be detected, the target DNA is complementarily combined with the base DNA, so that the electric characteristics of the field effect transistor 100 may be changed. Accordingly, the measured drain current may differ from the reference current.

On the other hand, the step of detecting the target DNA according to the comparison result (S140), when the difference value between the reference current and the drain current as a result of the comparison is less than (or less than) a threshold, determining that the target DNA has not been detected. Can include. For example, when the target DNA is not included in the target sample, the target sample is not bound to the base DNA. Accordingly, since the electric characteristics of the field effect transistor 100 are not changed, the drain current measured here may be the same as or almost similar to the reference current.

The methods according to the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like alone or in combination. The program instructions recorded on the computer-readable medium may be specially designed and configured for the present invention, or may be known and usable to those skilled in computer software.

Examples of computer-readable media may include hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions may include high-level language codes that can be executed by a computer using an interpreter or the like as well as machine language codes such as those produced by a compiler. The above-described hardware device may be configured to operate as at least one software module to perform the operation of the present invention, and vice versa.

In addition, the above-described method or apparatus may be implemented by combining all or part of its configuration or function, or may be implemented separately.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention within the scope not departing from the spirit and scope of the present invention described in the following claims. You will understand that you can do it.

10: complementary DNA 15: primer
20: base DNA 30: target DNA
100: field effect transistor 110: transistor array
200: sample introduction unit 210: current detection unit
220: reading unit 230: a plurality of current detection units
1000: device to detect target DNA

Claims (3)

A device that detects target DNA using a field effect transistor (FET),
A field effect transistor including a gate electrode connected to a reference power source, a drain electrode connected to a current detector, and a source electrode connected to ground;
A sample introduction part to which the base DNA is fixed in advance and coupled to the gate electrode;
A current detector for detecting a drain current of the field effect transistor, and
Comprising a reader for detecting the target DNA by comparing the drain current with a reference current, the apparatus for detecting the target DNA. In claim 1,
The base DNA,
A complementary DNA having a sequence complementary to the target DNA; And
An apparatus for detecting a target DNA, comprising a primer that binds to one end of the target DNA. In claim 1,
The field effect transistor,
An apparatus for detecting a target DNA, comprising: an active layer pattern disposed on one surface of a base layer on which a buffer layer is formed and including a channel region forming a channel and a drain region and a source region disposed on both sides of the channel region.

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