KR101083548B1 - Bio sensor using porous nano template and method for manufacture of bio sensor - Google Patents

Abstract

A nanocapacitor comprising a first electrode electrically connected to a lower portion of a metal nanowire formed inside an array of micropores formed in a porous nano template, and a second electrode disposed above the porous nano template and electrically separated from the first electrode. A biosensor chipped in an array form is provided.

Porous nano template, metal nanowire, capacitance change, bio sensor

Description

Bio sensor and bio sensor manufacturing method using porous nano template {BIO SENSOR USING POROUS NANO TEMPLATE AND METHOD FOR MANUFACTURE OF BIO SENSOR}

Embodiments of the present invention relate to a biosensor and a biosensor manufacturing method using a porous nano-template.

A biosensor is a device capable of selectively detecting a substance to be analyzed by combining a biological receptor having a recognition function for a specific substance with an electrical or optical transducer to convert biological interactions and recognition reactions into an electrical or optical signal.

Such biological receptors are enzymes, antigens, antibodies, proteins, DNA, cells, hormones, etc. that are used as biomolecules that selectively recognize analytes and generate signals that can be measured by the transducer. Electrochemical and optical methods are used as the method.

However, the most commonly used optical method using fluorescence has the disadvantage of attaching an optical dye that emits fluorescence, and label-free biosensors are actively studied to compensate for such disadvantages. have.

An example of the label free biosensor may include a biosensor measuring a change in capacitance according to the degree of bonding of a biomaterial to a surface of a capacitor by applying a nanocapacitor using a porous nano template.

Embodiments of the present invention provide a capacitance biosensor using a porous nano-template and a method of manufacturing the biosensor.

In addition, embodiments of the present invention is to provide a biosensor easy to integrate according to the pattern of the metal thin film.

In addition, embodiments of the present invention aims to provide a biosensor that does not require a label for biomaterial fractionation.

In addition, embodiments of the present invention aims to provide a biosensor capable of simultaneously classifying or classifying a plurality of biomaterials with higher sensitivity than conventional biosensors.

The biosensor according to an embodiment of the present invention is disposed on the first electrode electrically connected to the lower portion of the metal nanowires formed in the array of micropores formed in the porous nano template and electrically separated from the first electrode. And a second electrode.

In this case, the porous nano template may be a porous anodized aluminum template (PAO Template) formed by anodizing the patterned aluminum thin film on the wafer.

In addition, the method of manufacturing a biosensor according to an embodiment of the present invention includes the steps of forming a first electrode, and electroplating (electro-depostion) inside the micropore array of the porous nano-template to the upper portion of the first electrode. Forming a second electrode and forming a second electrode on top of the porous nano-template.

According to embodiments of the present invention can provide a biosensor using a porous nano-template and a method of manufacturing the biosensor.

In addition, according to embodiments of the present invention can provide a biosensor easy to integrate according to the pattern of the metal thin film.

In addition, according to embodiments of the present invention can provide a biosensor that does not require a label for the classification of biomaterials.

In addition, according to embodiments of the present invention, a plurality of biomaterials may be simultaneously classified or classified with higher sensitivity than conventional biosensors.

In addition, according to the embodiments of the present invention, since the nano-sized capacitors form an array in parallel, they may have a higher sensitivity than conventional sensors, and may be positioned on the first electrode and the template including the porous nano-template. Since it is made of a second electrode, it is easy to integrate in an array form, and thus various kinds of biomaterials can be detected at the same time.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings and the contents described in the accompanying drawings, but the present invention is not limited or limited to the embodiments.

On the other hand, in describing the present invention, when it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. The terminology used herein is a term used for appropriately expressing an embodiment of the present invention, which may vary depending on the user, the intent of the operator, or the practice of the field to which the present invention belongs. Therefore, the definitions of the terms should be made based on the contents throughout the specification.

1 is a plan view showing the configuration of a biosensor according to an embodiment of the present invention, Figure 2 is a side view showing the configuration of a biosensor according to an embodiment of the present invention.

1 to 2, a biosensor according to an embodiment of the present invention is largely positioned on a first electrode 120, a nanowire array 131 disposed on the first electrode, and an upper portion of the nanowire array. It is composed of a second electrode 150, in more detail using a first electrode 120 manufactured under the porous nano-template to form a metal wire in the micropore array by electroplating, and separated from the metal nanowire The second electrode 150 is deposited on the nanowire array 131 so as to be deposited.

That is, the biosensor according to the embodiment of the present invention forms the first electrode 120 and electroplats metal nanowires inside the micropore array of the porous template on the first electrode 120. After the metal nanowires are formed, the second electrode 150 separated from the metal nanowires may be formed on the porous nano template.

In this case, the porous template may be a porous anodized aluminum template (PAO Template) formed by anodizing an aluminum plate or an aluminum thin film. The method of manufacturing the porous template will be described later in detail with reference to FIG. 3.

In addition, the metal of the metal nanowire is stable in a liquid phase such as gold (Au), platinum (Pt), aluminum (Al), silver (Ag), chromium (Cr) or copper (Cu), and the biomolecules are bonded. It may be made of any one of the metals, the metal may have a diameter of 70 nm, 400 nm in length.

In addition, the first electrode is, for example, a group consisting of any one of Ti (titanium), gold (Au), platinum (Pt), aluminum (Al), silver (Ag), chromium (Cr) or copper (Cu). It may be any one metal thin film selected from, the second electrode, for example, Ti (titanium), gold (Au), platinum (Pt), aluminum (Al), silver (Ag), chromium (Cr ) Or a metal thin film of any one of metals that are stable in a liquid state such as copper (Cu) and to which a biomolecule can be bound.

3A to 3D are diagrams illustrating a process flow illustrating a method for preparing a polydimethylsiloane (PDMS) channel according to an embodiment of the present invention.

3A to 3D illustrate an exemplary method of manufacturing the PDMS channel, but the PDMS of the present invention is not limited to the following manufacturing method and may have various embodiments within the scope of the inventive concept.

3A to 3D, a mold for forming a multi-channel later is formed on a prepared wafer. In this case, the mold may be formed using photolithography and photoresist (SU-8 2150). In addition, a photoresist is first formed on a wafer prepared with a spin coater (eg, 2000 rpm, 30 seconds).

The formed thin film is baked at 65 ° C for 7 minutes and at 90 ° C for 1 hour using a hot plate, and after photolithography, only UV-protected portions remain on the wafer in a channel shape. The prepared mold is placed in a petri dish and poured with PDMS to solidify at a high temperature (for example, 80 degrees) for about 2 hours, and then shaken to prepare a PDMS channel.

<Examples>

Figures 4a to 4d is a view showing a process flow showing a method for manufacturing a porous template according to an embodiment of the present invention.

Although not shown in FIGS. 4A to 4D, a pattern of a metal substrate is formed by using photolithography on the first silicon wafer to manufacture the porous template.

That is, according to an embodiment of the present invention, in order to manufacture the porous template, first, a photoresist (eg, AZ 7210, Clariant Industries) in the process of creating a pattern where an aluminum thin film is to be deposited using photolithography. Ltd.) using a spin coater to form a thin film on the surface of the wafer, using a film mask and a mask aligner (for example, MDA-400A, midas system) to irradiate the ultraviolet light only to the desired surface and to immerse in a developer solution to form a pattern. Can be.

In addition, the porous template according to an embodiment of the present invention is subjected to a process of depositing the metal substrate on the pattern by using electron beam evaporation (electron beam evaporation).

That is, according to an embodiment of the present invention, in the process of depositing a thin film of aluminum by the electron beam deposition method on the pattern formed using the photolithography, because the adhesion between the aluminum and the wafer is not good, the aluminum is deposited Before the process, a process of depositing gold (0.5 nm) for titanium (10 nm) and later electrodepositing may be performed. At this time, the deposited thin film can be removed by dipping in acetone leaving only the thin film in the patterned area by using the property that the photoresist is dissolved in acetone.

4A to 4D illustrate an example in which the porous template is a porous anodized aluminum template formed by anodizing an aluminum plate or an aluminum thin film, but the porous template of the present invention is limited to a porous anodized aluminum template. Without departing from the scope of the present invention, the present invention may have various embodiments.

The porous anodized aluminum template according to an embodiment of the present invention has an anodizing portion formed vertically by applying a DC voltage to an aluminum metal and oxidizing the same, and uses an anodizing method to form a micropore array in the anodizing portion. That is, oxygen and aluminum combine to electrically oxidize aluminum in an acidic solution, and an aluminum oxide film is formed on the aluminum metal surface. Aluminum where oxidation occurs is called anodization because it is used as a positive electrode.

4A to 4D, an embodiment according to an actual process of the present invention will be described below.

First, the aluminum thin film 310 is first anodized to form an aluminum oxide 320 on the aluminum thin film 310 (FIG. 4A). According to an exemplary embodiment of the present invention, the first anodization is an anodizing electrolyte, and the first anodization is performed for 4 to 5 minutes under a concentration of 0.3 M oxalate (C2H2O4), a temperature of 15 ° C., and a voltage of 40 V. do. Although the micropores in the vertical length direction are formed on the surface of the aluminum oxide 320 by the first anodization treatment, the array of the micropores is irregular. In FIG. 4B, the irregular microporous array aluminum oxide 320 is dissolved in 1.8 wt% chromic acid (H 2 CrO 4) and 6 wt% phosphoric acid (H 3 PO 4) mixed solution at 60 ° C. for about 10 minutes, and removed from the aluminum thin film 310. Then, dimples are formed on the aluminum thin film. As shown in FIG. 4C, the aluminum thin film 310 is subjected to a second anodization for about 4 to 5 minutes under a first anodization condition to form an anodization unit 330 including a regular micropore array to form a porous anodized aluminum template. Form 300.

A photolithography process is then used to leave only the portion of the porous anodized template to be electroplated and the rest is covered with an insulating thin film.

According to one embodiment of the present invention, after anodization, an alumina barrier is inevitably formed at the end of the porous anodized aluminum template. To remove this, a 6 wt% phosphoric acid solution of the removed porous anodized aluminum template is removed. The barrier can be removed by soaking at room temperature for 35 minutes.

When the metal nanowires are formed by electroplating the porous anodized aluminum plate formed through the above-described process, the nanowire array 131 of the biosensor may be formed.

5 and 6 are scanning electron microscope (SEM) images showing the top and side cross-sections of the porous anodized aluminum template prepared in Example. Referring to FIGS. 5 and 6, the porous anodized aluminum template prepared in Example includes a micropore array arranged regularly, and the micropore array extends in the longitudinal direction of the anodization unit. Can be. For example, the micropores forming the micropore array may have a diameter of 50 ~ 200nm.

In addition, the biosensor according to an embodiment of the present invention was produced by attaching the PDMS channel on the porous anodized aluminum nano-capacitor nano-capacitor to analyze various biomaterials at the same time.

7A to 7F are diagrams illustrating a process flow illustrating a method of manufacturing a biosensor according to an embodiment of the present invention.

A method of manufacturing a biosensor according to an embodiment of the present invention will be described in detail below with reference to the above-described contents and FIGS. 7A to 7F. In this case, the reference numerals shown in FIGS. 7A to 7F are absent to correspond to FIGS. 1 to 2 for matching components.

As described above, as a previous step for manufacturing a nanocapacitor for use as a biosensor according to an embodiment of the present invention, first, a porous anodized aluminum template patterned by photolithography may be manufactured.

As described above, in order to form a nanocapacitor structure on the porous anodized aluminum template, the porous anodized aluminum template is formed by using an aluminum thin film deposited on a patterned upper portion of the silicon pattern 110, and using an electroplating method. Gold nanowires are formed in the porous anodized aluminum holes with the metal nanowires 131.

In this case, before forming the metal nanowires 131, the remaining portions other than the portion where the metal nanowires 131 are plated and the portion to be wire bonded later, that is, the nanowire array, the first electrode 120, and the second portion Insulating thin films, such as SiO ₂ or SiN, are deposited in regions other than the electrode 150 and the wire bonding region.

On the other hand, the electroplating electrolyte, for example, using HAuCl4 pH4, pH can be adjusted to H2SO4 and 0.1M H2BO3, using a constant voltage meter (potentiostat, Princeton Appleid Research, Powersuite 2.40) constant current of 3 mA / cm2 To be plated into the PAO template.

In this case, the constant voltage meter may be composed of a platinum counter electrode, a reference electrode, a reference electrode (Ag / AgCl in 3.5 M KCl solution), and a working electrode (PAO template patterned wafer). A constant voltage or current may be applied and maintained between the auxiliary electrode and the working electrode.

Next, according to an embodiment of the present invention, in order to use the second electrode 150 which is another electrode of the nanocapacitor, the nanowire array to separate the second electrode 150 from the metal nanowire 131. Deposited on top of 130, for example, chromium (Cr 4 nm) and gold (Au 40 nm) are deposited only on the patterned porous anodized aluminum using a shadow mask and a thermal evaporator.

Lastly, as described above, the PDMS channel 160, which has been previously prepared for analyzing various biomaterials, may be attached to a suitable position on the nanocapacitor.

8 is an electron microscope cross-sectional image of a nanocapacitor manufactured according to an embodiment of the present invention.

Referring to FIG. 8, gold nanowires, which are metal nanowires, were vertically aligned and plated on the porous anodized aluminum hole, and chromium (Cr) and gold (Au) were deposited on the upper surface of the template with the second electrode 150. have.

9 is a view showing a DNA surface treatment experiment process using a biosensor according to an embodiment of the present invention.

As a biosensor according to an embodiment of the present invention, a hybridization analysis of DNA may be performed. For this, two kinds of DNAs having different lengths may be used to simultaneously display three channels. The experiment was to proceed.

At this time, thiol (-SH) was injected into the channel using a syringe pump to thiol (DNA) dissolved in PBS pH8 by using a chemically bound to the gold surface in a PBS solution of pH8.

According to one embodiment of the present invention, a gold pattern is deposited on the silicon (SiO 2) and the porous anodized aluminum template, respectively, in order to check the degree of bonding of the thiol to the gold-deposited porous anodized aluminum template.

10 is a view showing the results of fluorescence experiments according to an embodiment of the present invention.

In addition, the FITC fluorescent particles attached to the same 30mer thiol DNA as in the actual experiment was confirmed by binding to a pattern sample prepared in advance, as shown in the left figure shown in Figure 10, much more in the gold pattern on the porous anodized aluminum template Fluorescence was observed.

After the preparation process as described above, in order to perform DNA complementary binding experiments in the biosensor according to an embodiment of the present invention, the three channels were first combined with 30mer and 90mer thiol-DNA, respectively, and the other channel was compared. The experiment was run with nothing bound.

Next, thiol-DNA and complementary DNA were injected into three channels simultaneously in the order of 30mer and 90mer. When 30mer DNA was injected, only thiol-30mer-DNA was previously attached to the gold surface. When the 90mer DNA was injected, only the thiol-90mer-DNA channel showed a change in capacitance.

11 is a graph showing a change in capacitance according to an embodiment of the present invention.

According to one embodiment of the invention, as shown in Figure 11, it can be seen that there is a change in capacitance only when complementary DNA is injected into the channel. Therefore, the biosensor according to an embodiment of the present invention can find the DNA complementary to the surface-treated DNA by the change in capacitance.

In addition, the biosensor according to an embodiment of the present invention can find the antigen that reacts to the surface-treated antibody using the antigen-antibody reaction if the antibody is surface-treated in advance.

12 is a graph showing the change in capacitance according to the DNA concentration complementary to 30mer DNA according to an embodiment of the present invention.

Referring to FIG. 12, in the biosensor according to an exemplary embodiment of the present invention, the concentration of the biosensor can observe the change in the capacitance in proportion to each other. The concentration of the sample in the sample can be confirmed by the manufactured biosensor.

Embodiments according to the present invention can be implemented in the form of program instructions that can be executed by various computer means can be recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

As described above, the present invention has been described by specific embodiments such as specific components and the like. For those skilled in the art to which the present invention pertains, various modifications and variations are possible. Therefore, the spirit of the present invention should not be limited to the described embodiments, and all of the equivalents or equivalents of the claims as well as the claims to be described later will belong to the scope of the present invention. .

1 is a plan view showing the configuration of a biosensor according to an embodiment of the present invention.

2 is a side view showing the configuration of a biosensor according to an embodiment of the present invention.

3A to 3D illustrate a process flow illustrating a method for manufacturing a PDMS channel according to an embodiment of the present invention.

Figures 4a to 4d is a view showing a process flow showing a method for producing a porous nano-template according to an embodiment of the present invention.

5 and 6 are scanning electron microscope (SEM) images showing the top and side cross-sections of the porous anodized aluminum template prepared in Example.

7A to 7F are diagrams illustrating a process flow illustrating a method of manufacturing a biosensor according to an embodiment of the present invention.

8 is an electron microscope cross-sectional image of a nanocapacitor manufactured according to an embodiment of the present invention.

9 is a view showing a DNA surface treatment experiment process using a biosensor according to an embodiment of the present invention.

10 is a view showing the results of fluorescence experiments according to an embodiment of the present invention.

11 is a graph showing a change in capacitance according to an embodiment of the present invention.

12 is a graph showing the change in capacitance according to the DNA concentration complementary to 30mer DNA according to an embodiment of the present invention.

Claims (18)

A nanowire array including metal nanowires formed inside an array of micropores formed in the porous nano template; A first electrode electrically connected to a lower portion of the metal nanowire exposed to a lower portion of the porous nano template and positioned below the porous nano template; And A second electrode on the porous nano template Biosensor comprising a. The method of claim 1, The porous nano template A biosensor, which is a porous anodized aluminum template (PAO Template) formed by anodizing an aluminum plate or an aluminum thin film. 3. The method of claim 2, The micro-pores forming the micro-pore array has a diameter of 50 ~ 200nm. The method of claim 1, The metal nanowire is any one of gold (Au), platinum (Pt), aluminum (Al), silver (Ag), chromium (Cr) or copper (Cu). The method of claim 1, The first electrode, A biosensor which is any one metal thin film selected from the group consisting of Ti, gold (Au), platinum (Pt), aluminum (Al), silver (Ag), chromium (Cr) or copper (Cu). The method of claim 1, The second electrode, A biosensor which is any one metal thin film selected from the group consisting of Ti, gold (Au), platinum (Pt), aluminum (Al), silver (Ag), chromium (Cr) or copper (Cu). The method of claim 1, The second electrode, Biosensor, characterized in that formed on top of the nanowire array to be separated from the metal nanowire. The method of claim 1, A biosensor further comprising any one of insulatingly available SiO 2 and SiN deposited in a region excluding the nanowire array, the first electrode, the second electrode, and the wire bonding region. The method of claim 1, PDMS channel located above the second electrode Biosensor further comprising a. Forming a first electrode; Electro-deposition metal nanowires within the micropore array of the porous template on top of the first electrode to form a nanowire array such that the metal nanowires are connected to the first electrode; And Forming a second electrode on top of the porous nano template Biosensor manufacturing method comprising a. The method of claim 10, The porous nano template A biosensor manufacturing method, which is a porous anodized aluminum template formed by anodizing an aluminum plate or an aluminum thin film. The method of claim 10, The first electrode is a biosensor manufacturing method electrically connected to the lower portion of the metal nanowires. The method of claim 10, The second electrode, And forming a biosensor on the nanowire array so as to be separated from the metal nanowires. The method of claim 10, The step of forming a nanowire array so that the metal nanowires are connected to the first electrode by electro-deposition metal nanowires inside the micropore array of the porous nano-template on the first electrode, Forming a pattern of a metal substrate using photolithography on the silicon wafer; Depositing the metal substrate on the pattern by using electron beam evaporation; Anodizing the metal substrate to prepare a porous nano template including the micropore array; And Electroplating the metal nanowire on the porous nano template to be connected to the first electrode Biosensor manufacturing method comprising a. The method of claim 14, The step of preparing a porous nano-template comprising the micropore array by anodizing the metal substrate, First anodizing the metal substrate to form an oxidized metal substrate on the metal substrate; Removing the oxidized metal substrate from the metal substrate and subjecting the metal substrate to a second anodization to form the porous template including an anodization portion in which the micropore array is formed; And Separating the porous template from the metal substrate Biosensor manufacturing method comprising a. The method of claim 15, The step of preparing a porous nano-template comprising the micropore array by anodizing a metal substrate, Depositing a metal thin film on one surface of the porous nano template Biosensor manufacturing method further comprising. The method of claim 10, Forming one of the insulating-available SiO 2 and SiN thin films deposited in a region excluding the nanowire array, the first electrode, the second electrode, and the wire bonding region. Biosensor manufacturing method further comprising. The method of claim 10, Forming a PDMS channel positioned on the second electrode Biosensor manufacturing method further comprising.

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