Composite material for thermal cycler heat block and low specific heat thermal block for thermal cycler manufactured using the same

Abstract

The present invention relates to a composite material for a thermal block of a thermal cycler, which has low specific heat characteristics and significantly improved thermal conductivity. In the case of a thermal block manufactured using the composite material, when the temperature of the thermal block rises or falls, the deviation in the temperature change rate between multiple unit thermal blocks and / or between different regions within the unit thermal block can be significantly reduced. Therefore, a PCR thermal cycler including the thermal block can ensure reliability even in ultra-high speed PCR reactions.

Description

[Technical Field]

[0001] The present invention relates to a composite material for a thermal cycler heat block, and more particularly to a composite material for a thermal cycler heat block having excellent thermal conductivity and low specific heat, and a low specific heat heat block for a thermal cycler manufactured using the same. [Background technology]

[0002] With the recent development of industry, the number of heat-dissipating and heat-generating electronic products has increased, and technology related to materials with excellent thermal conductivity has become recognized as a very important field.Their importance is increasing in the areas of heat dissipation parts for personal computers, heat sinks for light-emitting diodes (LEDs), and thermal block parts for thermal cyclers.In particular, as the importance of thermal cyclers increases as basic diagnostic equipment required for genetic testing, heat transfer material technology for high-speed testing is attracting a great deal of attention.

[0003] In the field of biotechnology, especially genetic diagnosis, the PCR (Polymerase Chain Reaction) thermal cycler is the most important piece of equipment. PCR is a DNA replication technique called the Polymerase Chain Reaction (PCR), developed by Mullis et al. in 1983. PCR is a method of continuously replicating template DNA using enzymes. PCR is divided into three steps: the melting step, which unwinds the double-stranded template DNA (the target of replication) into a single strand; the annealing step, which specifies the starting position of the reaction on the unwound single strand and attaches a primer of several dozen bases that helps to start the enzymatic reaction; and the extension step, which replicates the DNA from the primer position to create a complete double-helix DNA.

[0004] When the above three steps are carried out, the amount of DNA is theoretically doubled, and when this process is repeated n times, the amount of DNA is theoretically increased by 2n times.

[0005] Generally, a PCR thermal cycler uses a temperature-controllable thermal block, which controls the temperature by periodically increasing and decreasing the temperature at predetermined time intervals.

[0006] The core component of a PCR (Polymerase Chain Reaction) thermal cycler is a thermal block with excellent thermal properties. PCR involves repeated temperature rises and falls, which requires a thermal block with high thermal conductivity and low specific heat. Until now, thermal blocks have been made of aluminum, but in the case of high-speed PCR thermal cyclers, silver is used.

[0007] However, the aluminum used in these PCR thermal cyclers has poor specific heat performance, making it difficult to achieve high-speed PCR reactions, which is currently a major problem. Furthermore, the use of silver poses economical problems due to its high cost. Therefore, research into various heat conductor materials is ongoing to resolve these issues.

[0008] To solve this problem, a heat block has been proposed that is manufactured using a composite material in which tin powder, which has excellent specific heat properties, and metal powder, which has excellent thermal conductivity, are mixed.

[0009] However, in PCR thermal cyclers equipped with multiple unit heat blocks, the thermal conductivity of the unit heat blocks is poor, and there is a large deviation in the temperature rise and fall rates between unit heat blocks or between different regions within a unit heat block. This has the disadvantage of reducing the reliability of the PCR thermal cycler when performing ultrafast PCR reactions.

[0010] Therefore, there is a need to develop a composite material that can provide a thermal cycler heat block that has excellent specific heat properties and significantly improved thermal conductivity properties. Summary of the Invention [Problem to be solved by the invention]

[0011] An object of the present invention is to provide a composite material for a heat block of a thermal cycler that has low specific heat characteristics and excellent thermal conductivity characteristics.

[0012] Another object of the present invention is to provide a low specific heat heat block for a thermal cycler that has excellent thermal conductivity characteristics and can significantly reduce deviations in the rate of temperature change when the temperature is increased or decreased.

[0013] It is yet another object of the present invention to provide a PCR thermal cycler that includes the above-mentioned heat block and thereby ensures reliability even in ultrafast PCR reactions. [Means for solving the problem]

[0014] According to one aspect of the present invention, there is provided a composite material for a thermal block of a thermal cycler, the composite material comprising a powder metal which is a first metal or an alloy containing the first metal; and metal nanowires having a core-shell structure in which a shell containing a third metal is located on a core containing a second metal.

[0015] In the composite material for a thermal block of a thermal cycler according to one embodiment of the present invention, the first metal is tin, and the alloy may be one or more selected from the group consisting of tin-silver, tin-copper, tin-aluminum, tin-bismuth, tin-antimony, tin-copper-bismuth, tin-silver-bismuth, tin-copper-antimony, tin-silver-antimony, tin-copper-silver, tin-copper-silver-antimony, and tin-copper-silver-bismuth.

[0016] In the composite material for a thermal block of a thermal cycler according to one embodiment of the present invention, the second metal may be copper, and the third metal may be silver or gold.

[0017] In the composite material for a thermal block of a thermal cycler according to an embodiment of the present invention, the metal nanowires may be silver-coated copper nanowires.

[0018] In accordance with an embodiment of the present invention, there is provided a composite material for a thermal block of a thermal cycler, wherein the metal nanowires are Ag 3d in X-ray photoelectron spectroscopy. 5 / 2 The peak intensity I1 and Cu 2p 3 / 2 The peak intensity I2 may satisfy the following formula 1: (Formula 1) I2 / I1≦0.2 In the composite material for a thermal block of a thermal cycler according to one embodiment of the present invention, the metal nanowires may have a diameter of 100-500 nm and an aspect ratio of 5-100.

[0019] In accordance with an embodiment of the present invention, there is provided a composite material for a thermal block of a thermal cycler, wherein the powder metal has a particle diameter D p : diameter of metal nanowire D w The ratio (D p / D w ) may be 1:0.0001 to 0.01.

[0020] In the composite material for a thermal block of a thermal cycler according to an embodiment of the present invention, the weight ratio of the powder metal to the metal nanowires may be 1:0.001 to 0.1.

[0021] According to another aspect of the present invention, there is provided a low specific heat thermal block for a thermal cycler, which is manufactured by sintering, casting, rolling or casting the above-mentioned composite material.

[0022] According to another aspect, the present invention also provides a low specific heat heat block for a thermal cycler, comprising tin or a tin alloy and silver-coated copper nanowires.

[0023] In the low specific heat heat block of the thermal cycler according to one embodiment of the present invention, the weight ratio of the tin or tin alloy to the silver-coated copper nanowires may be 1:0.001 to 0.1.

[0024] In the low specific heat heat block of the thermal cycler according to one embodiment of the present invention, the silver-coated copper nanowires exhibit Ag 3d of silver in X-ray photoelectron spectroscopy. 5 / 2 The peak intensity I1 and Cu 2p 3 / 2 The peak intensity I2 may satisfy the following formula 1: (Formula 1) I2 / I1≦0.2

[0025] In the low specific heat heat block of the thermal cycler according to one embodiment of the present invention, the thermal conductivity of the heat block may be 70 to 100 W / (m·K) at 21°C.

[0026] According to yet another aspect of the present invention, there is provided a PCR (Polymerase Chain Reaction) thermal cycler comprising: a heating element; and a thermal block having one end contacting one surface of the heating element and having an insertion hole at another end opposite the one end, wherein the thermal block is formed by sintering, casting, rolling, or casting the composite material described above.

[0027] In the PCR (Polymerase Chain Reaction) thermal cycler provided according to one embodiment of the present invention, the heat block may satisfy the following formula 2: (Formula 2) H a -H b ≦±0.5℃ / sec In formula 2, H a is the heating rate in the 0.1 to 0.3t region, defined as region A, based on one end of the heat block that is in contact with one surface of the heating element, and H b is the heating rate in the 0.7t to 1.0t region, defined as region B. [Effects of the Invention]

[0028] The composite material for the heat block of a thermal cycler of the present invention has the advantage of having low specific heat properties and significantly improved thermal conductivity properties, by containing a powder metal that is a first metal or an alloy containing the first metal, and metal nanowires with a core-shell structure in which a shell containing a third metal is located on a core containing a second metal.

[0029] Furthermore, in the case of a thermal block manufactured using the above-mentioned composite material, when the temperature of the thermal block is increased or decreased, there is an advantage that the deviation in the temperature change rate between multiple unit thermal blocks and / or between different regions within a unit thermal block can be significantly reduced.

[0030] Furthermore, a PCR thermal cycler including the above-mentioned heat block has the advantage of ensuring reliability even in ultrafast PCR reactions. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a schematic diagram illustrating a sintering, casting, rolling, or casting process for a low specific heat composite material including silver-coated copper nanowires in tin or a tin alloy according to the present invention. [Figure 2]1 is a schematic diagram showing a three-dimensional drawing of a thermal block molded product of a thermal cycler manufactured by sintering, casting, rolling or casting the low specific heat composite material according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, a composite material for a thermal cycler heat block and a low specific heat heat block of a thermal cycler including the same according to the present invention will be described in more detail with reference to the following embodiments. However, the following embodiments are merely references for explaining the present invention in detail, and the present invention is not limited thereto and may be realized in various forms.

[0033] Furthermore, unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used in the description herein are merely for the purpose of effectively describing particular embodiments and are not intended to limit the present invention.

[0034] In addition, descriptions of known effects and configurations that may obscure the gist of the present invention will be omitted. Hereinafter, units used in the specification without special mention are based on weight, and for example, units of % or ratio mean weight % or weight ratio.

[0035] Also, as used in the present specification, the singular forms "a," "an," and "the" may be intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0036] Furthermore, in this specification, when a part is described as "comprising" a certain component, this does not mean that it excludes other components, but that it may further include other components, unless otherwise specified to the contrary.

[0037] In addition, the numerical ranges used herein include lower and upper limits, and all values ​​within the range, increments logically derived from the form and width of the defined range, all values ​​limited therein, and all possible combinations of upper and lower limits of numerical ranges limited in different forms. Unless otherwise specified in the specification of the present invention, values ​​outside the numerical range that may occur due to experimental error or rounding off of values ​​are also included in the defined numerical range.

[0038] A composite material for a thermal block of a thermal cycler according to one embodiment of the present invention includes a powder metal that is a first metal or an alloy containing the first metal, and metal nanowires having a core-shell structure in which a shell containing a third metal is located on a core containing a second metal.

[0039] Gene amplification technology using polymerase chain reaction (PCR) is widely used in fields such as biotechnology, genetic engineering, and medicine for research, development, and diagnostic purposes.

[0040] PCR is a reaction that uses enzymes to continuously replicate a template gene through the steps of melting, annealing, and extension, and amplifies the amount of the gene by repeating these steps.

[0041] Here, the denaturation step is typically performed at 95°C, and the annealing and extension steps are performed at 75°C or below. However, as mentioned above, in order to amplify the gene by repeating each step, the temperature of the gene sample must be repeatedly raised and lowered.

[0042] Gene amplification requires a device capable of adjusting the temperature of a gene sample, and a thermal cycler is widely used as such a device.

[0043] Typically, PCR thermal cyclers use a temperature-controllable thermal block, which periodically raises and lowers the temperature at predetermined time intervals to control the temperature. The thermal block must have excellent thermal conductivity and low specific heat. It is generally made of aluminum, while high-speed PCR thermal cyclers use silver.

[0044] However, aluminum has poor specific heat properties and is therefore limited in its use in high-speed PCR reactions, and methods using silver are not economical and have limitations on their use.

[0045] To solve these problems, conventionally, heat blocks have been manufactured using a composite material that combines tin powder and metal powder with excellent thermal conductivity. However, in PCR thermal cyclers equipped with multiple unit heat blocks, the unit heat blocks have poor thermal conductivity, resulting in large deviations in the temperature rise and fall rates between unit heat blocks and / or between different regions within a unit heat block, which reduces the reliability of the PCR thermal cycler when performing ultrafast PCR reactions.

[0046] Meanwhile, the composite material for a thermal block of a thermal cycler according to one embodiment of the present invention contains powder metal and core-shell structured metal nanowires, and therefore has low specific heat characteristics, significantly improved thermal conductivity characteristics, and is advantageous in terms of economy. Therefore, a thermal block manufactured using the above-mentioned composite material has the advantages of being economical and significantly reducing the deviation in the temperature change rate between multiple unit thermal blocks and / or between different regions within a unit thermal block when the temperature of the thermal block is increased or decreased. Furthermore, a PCR thermal cycler including the above-mentioned thermal block has the advantage of ensuring reliability even in ultra-high-speed PCR reactions.

[0047] Specifically, the powder metal and core-shell structured metal nanowires contained in the composite material for the thermal cycler's heat block can be compression molded to manufacture the thermal cycler's heat block. Here, the flexible metal nanowires are densely compressed together with the powder metal and form a network between the metal nanowires, providing a uniform thermal transport path within the heat block, significantly improving thermal conductivity characteristics and significantly reducing deviations in temperature rise and fall rates between unit heat blocks and / or in different regions within the unit heat block.

[0048] Meanwhile, when manufacturing a thermal block using a composite material in which tin powder and metal powder with excellent thermal conductivity are mixed, as in the past, there is a limit to how uniformly the metal powder with excellent thermal conductivity can be dispersed. As a result, the thermal transfer path within the block is formed randomly, resulting in large deviations in the temperature rise and fall rates between unit thermal blocks and / or between different regions within the unit thermal block.

[0049] In one embodiment, in the first metal or alloy containing the first metal, which is a powder metal, the first metal is tin, and the alloy may be one or more selected from the group consisting of tin-silver, tin-copper, tin-aluminum, tin-bismuth, tin-antimony, tin-copper-bismuth, tin-silver-bismuth, tin-copper-antimony, tin-silver-antimony, tin-copper-silver, tin-copper-silver-antimony, and tin-copper-silver-bismuth.

[0050] The use of tin or an alloy containing tin as the powder metal in a composite material for a thermal cycler heat block can impart low specific heat properties to the heat block manufactured using the composite material.

[0051] As a specific example, the powder metal may have an average particle size of 40 to 200 μm, specifically 70 to 140 μm, and more specifically 80 to 120 μm.

[0052] In one embodiment, the second metal contained in the core of the core-shell structured metal nanowire contained in the composite material may be a metal with superior thermal conductivity compared to the first metal, and as an advantageous example, the second metal may be copper, taking into consideration thermal conductivity properties as well as economic efficiency.

[0053] As a specific example, in a metal nanowire with a core-shell structure, the third metal contained in the shell may be a metal that has a thermal conductivity similar to or equal to or higher than the thermal conductivity of the second metal and satisfies the following formula 1:

[0054] Here, a level similar to or equal to or higher than the thermal conductivity of the second metal may mean a level that is at least 70%, 80%, 90%, or 100% of the thermal conductivity of the second metal, and there is no upper limit.

[0055] (Formula 1) 0.6≦C1 / C3≦2

[0056] (In Equation 1, C1 is the specific heat of the first metal, and C3 is the specific heat of the third metal.)

[0057] As a specific example, the ratio (C1 / C3) of the specific heat of the first metal (C1) to the specific heat of the third metal (C3) may be 0.6 or more, 0.7 or more, 0.8 or more, 0.9 or more, or may be substantially 2 or less.

[0058] In this way, in the metal nanowire, the third metal contained in the shell has a thermal conductivity similar to or equal to that of the second metal and satisfies the following formula 1, so that it can be included in a composite material for a thermal cycler heat block together with the above-mentioned first metal or a powder metal that is an alloy containing the first metal, and the heat block manufactured using the composite material can have remarkably excellent thermal conductivity characteristics along with low specific heat characteristics.

[0059] In one example, the third metal may be silver or gold.

[0060] In one embodiment, the diameter of the core-shell metal nanowire may be 100 to 500 nm, specifically 150 to 500 nm, and more specifically 200 to 500 nm, and the aspect ratio of the metal nanowire may be 5 to 100, preferably 8 to 60, and more preferably 10 to 40.

[0061] By ensuring that the diameter and aspect ratio of the metal nanowires contained in the composite material for the thermal cycler heat block satisfy the above-mentioned ranges, a stable and uniform heat transfer path can be provided within the heat block when the heat block is manufactured using the composite material.

[0062] In one advantageous example, the metal nanowires may be silver coated copper nanowires.

[0063] Silver-coated copper nanowires have low specific heat and excellent thermal conductivity, and are useful for improving the thermal properties of thermal blocks manufactured using the composite material when included in a composite material for thermal cyclers together with a powder metal, which is a first metal or an alloy containing the first metal. Furthermore, the cost required to significantly improve the thermal properties is not high, making them economically advantageous.

[0064] As a specific example, when the metal nanowire is a silver-coated copper nanowire, the metal nanowire has a silver Ag 3d structure in the X-ray photoelectron spectroscopy spectrum. 5 / 2 The peak intensity I1 and Cu 2p 3 / 2 The peak intensity I2 may satisfy the following formula 2:

[0065] (Formula 2) I2 / I1≦0.2

[0066] In the case of copper, it easily oxidizes when exposed to air, and the electrical and thermal properties may be reduced due to the formation of copper oxide. However, as described above, metal nanowires, i.e., silver-coated copper nanowires, satisfying the above formula 2 have excellent oxidation stability, which may be advantageous for maintaining the original electrical and thermal properties of the silver-coated copper nanowires.

[0067] In one specific example, the X-ray photoelectron spectroscopy spectrum shows the Ag 3d 5 / 2 The peak intensity I1 and Cu 2p 3 / 2 The ratio (I2 / I1) of the peak intensity I2 to the peak intensity I3 may be 0.2 or less, preferably 0.1 or less, more preferably 0.05 or less, and even more preferably 0.03 or less, or may be 0.001 or more.

[0068] X-ray photoelectron spectroscopy of silver Ag 3d 5 / 2 The peak intensity I1 and Cu 2p 3 / 2 If the ratio of peak intensities I2 (I2 / I1) exceeds 0.2, the copper exposed to the outside of the core-shell metal nanowire may be oxidized, which may reduce the oxidation stability of the metal nanowire. 5 / 2 The peak intensity I1 and Cu 2p 3 / 2 It is preferable that the ratio (I2 / I1) of the peak intensity I1 to the peak intensity I2 satisfies the above range.

[0069] As a specific example, the thickness of the silver coating, i.e., the cell, may be 5 to 40 nm, specifically 5 to 30 nm, more specifically 5 to 20 nm, and even more specifically 6 to 10 nm.

[0070] If the shell thickness is less than 5 nm, oxidation of the copper contained in the core cannot be effectively suppressed, and if the shell thickness is 40 nm or more, the uniformity of the shell located on the core will be poor, which may result in the possibility of copper oxide formation and is not economically advantageous. Therefore, it is preferable that the shell thickness be within the above range.

[0071] In one embodiment, the average particle size D of the powder metal contained in the composite material for the thermal block of the thermal cycler p : diameter of metal nanowire D w The ratio (D p / D w ) may be 1:0.0001 to 0.01, specifically 1:0.0005 to 0.005.

[0072] By ensuring that the ratio of the average particle size of the powder metal contained in the composite material for the thermal cycler heat block to the diameter of the metal nanowires satisfies the above range, the compactness of the heat block can be improved when the composite material is used to manufacture the heat block.

[0073] Here, the composite material for the heat block of the thermal cycler may contain 0.1 to 60 wt %, specifically 0.5 to 30 wt %, more specifically 1 to 10 wt % of metal nanowires.

[0074] In one embodiment, the weight ratio of powder metal to metal nanowires contained in the composite material for the heat block of a thermal cycler may be 1:0.001-0.5, advantageously 1:0.001-0.1, more advantageously 1:0.005-0.1, and even more advantageously 1:0.01-0.05.

[0075] For example, a composite material for a thermal cycler heat block can be manufactured by physically mixing powdered metal and metal nanowires. If the weight ratio of powdered metal to metal nanowires is less than 0.001, the powdered metal and metal nanowires can be mixed uniformly, but the formation of a thermal transport path due to the formation of a metal nanowire network is limited, limiting the improvement of thermal conductivity. Furthermore, if the weight ratio of powdered metal to metal nanowires exceeds 0.5, the powdered metal and metal nanowires are not mixed uniformly, which may actually reduce thermal conductivity. Furthermore, the inclusion of an unnecessarily large amount of metal nanowires may reduce economic viability. Therefore, it is preferable that the weight ratio of powdered metal to metal nanowires contained in the composite material for a thermal cycler heat block satisfy the above range.

[0076] Here, the composite material for the heat block of a thermal cycler can be manufactured using a mixer that rotates the powder metal and metal nanowires at high speed, satisfying the weight ratio described above. For example, the rotation speed of the mixer that rotates at high speed may be 150 to 1000 rpm, specifically 300 to 800 rpm, and more specifically 400 to 600 rpm.

[0077] Furthermore, in order to uniformly mix the powder metal and metal nanowires, the mixing process using a mixer rotating at high speed can be carried out one or more times, two or more times, or three or more times, and although there is no upper limit, it goes without saying that it can be carried out substantially ten times or less.

[0078] The present invention provides a low specific heat heat block for a thermal cycler, which is manufactured by sintering, casting or molding the composite material for a thermal cycler heat block described above.

[0079] The present invention also provides a low specific heat heat block for a thermal cycler comprising tin or a tin alloy and silver-coated copper nanowires.

[0080] Here, the tin alloy is similar to or the same as the alloy containing the first metal described above, and a detailed description thereof will be omitted.

[0081] In one embodiment, the weight ratio of tin or tin alloy to silver-coated copper nanowires may be 1:0.001-0.5, advantageously 1:0.001-0.1, more advantageously 1:0.005-0.1, and even more advantageously 1:0.01-0.05.

[0082] By including tin or a tin alloy and silver-coated copper nanowires in the heat block in the above weight ratio, a network can be formed between the silver-coated copper nanowires, providing a uniform heat transfer path within the heat block. This has the advantage of significantly reducing the deviation in the temperature rise and fall rates between unit heat blocks and / or between different regions within the unit heat block.

[0083] In one embodiment, silver-coated copper nanowires are characterized by the Ag 3d structure in X-ray photoelectron spectroscopy. 5 / 2 The peak intensity I1 and Cu 2p 3 / 2 The peak intensity I2 may satisfy the following formula 2:

[0084] (Formula 2) I2 / I1≦0.2

[0085] When the silver-coated copper nanowires satisfy the above formula 2, they have excellent oxidation stability, which may be advantageous for maintaining the original electrical and thermal properties of the silver-coated copper nanowires.

[0086] In one specific example, the X-ray photoelectron spectroscopy spectrum shows the Ag 3d 5 / 2 The peak intensity I1 and Cu 2p 3 / 2 The ratio (I2 / I1) of the peak intensity I2 to the peak intensity I3 may be 0.2 or less, preferably 0.1 or less, more preferably 0.05 or less, and even more preferably 0.03 or less, or may be 0.001 or more.

[0087] X-ray photoelectron spectroscopy of silver Ag 3d 5 / 2 The peak intensity I1 and Cu 2p 3 / 2 If the ratio of peak intensities I2 to I1 (I2 / I1) is greater than 0.2, the copper exposed outside the silver-coated copper nanowires may be oxidized, which may reduce the oxidation stability of the silver-coated copper nanowires. 5 / 2 The peak intensity I1 and Cu 2p 3 / 2 It is preferable that the ratio (I2 / I1) of the peak intensity I1 to the peak intensity I2 satisfies the above range.

[0088] Here, the silver-coated copper nanowires are similar to or identical to the above-mentioned core-shell structured metal nanowires, and detailed descriptions regarding the diameter, aspect ratio, and thickness of the silver coating layer of the silver-coated copper nanowires will be omitted.

[0089] In one embodiment, the thermal conductivity of the low specific heat heat block of the thermal cycler may be 70 to 150 W / (m·K), specifically 70 to 100 W / (m·K), more specifically 70 to 80 W / (m·K) at 21°C.

[0090] As a specific example, the low specific heat heat block of a thermal cycler has a density of 5 to 20 g / mL, specifically 5 to 10 g / mL, a heat capacity of 0.2 to 1 J / (g K), specifically 0.2 to 0.5 J / (g K), and a volumetric heat capacity of 1 to 2 J / (cm 3 K), specifically 1 to 1.8 J / (cm 3 K).

[0091] As described above, the low specific heat thermal block of the thermal cycler contains tin or a tin alloy and silver-coated copper nanowires satisfying the above formula 2, and by having the above physical properties, it has the advantage of being able to significantly reduce the deviation in the temperature change rate between multiple unit thermal blocks and / or between different regions within a unit thermal block when the temperature of the thermal block increases or decreases.

[0092] The present invention also provides a PCR (Polymerase Chain Reaction) thermal cycler, which includes a heating element and a thermal block having one end contacting one surface of the heating element and having an insertion hole at another end opposite the one end, wherein the thermal block is formed by sintering, casting, rolling, or casting the composite material described above.

[0093] A PCR thermal cycler according to one embodiment of the present invention includes a thermal block formed using the above-described composite material, which can significantly improve heat transfer efficiency, thereby improving the efficiency of gene amplification reactions and ensuring reliability in ultrafast PCR reactions.

[0094] As a specific example, the heating element may be a heat source in which one end of a heat block contacts one surface of the heating element, and the heating element can transfer heat to the heat block and perform a cooling function.

[0095] As a specific example, the heating element may be a Peltier element, in which heat generation and cooling are performed in the same element by reversing the current direction, with the lower surface of the Peltier element acting as a cooler and the upper surface in contact with one end of the heat block generating heat.

[0096] Here, in order to improve the cooling efficiency, a heat sink may be attached to the lower surface of the Peltier element.

[0097] In one embodiment, the thermal block may include an insertion hole at one end opposite the end that contacts one surface of the heating element, and a reagent or sample container may be inserted into the thermal block through the insertion hole, so that the inner surface of the thermal block and the outer surface of the container come into surface contact with each other, thereby inducing a temperature change of the reagent or sample. Here, the shape of the insertion hole may be the same as the outer shape of the reagent or sample container, and the present invention is not limited by the shape of the insertion hole.

[0098] In one embodiment, the heat block may satisfy Equation 3 below:

[0099] (Formula 3) H a -H b ≦±0.5℃ / sec

[0100] In formula 3, H a is the heating rate in the 0.1 to 0.3t region, defined as region A, based on one end of the heat block that is in contact with one surface of the heating element, and Hb is the heating rate in the 0.7t to 1.0t region, defined as region B.

[0101] Here, the heating rate may be the ratio (ΔT / Δs) of the temperature change (ΔT) measured based on the initial temperature to the time change (Δs) calculated by measuring the temperature in area A and area B after 15 seconds when raising the temperature to 95°C using a heating element.

[0102] In one embodiment, the difference in heating rate between region A and region B (H a -H b ) may be ±0.5°C / sec or less, ±0.4°C / sec or less, ±0.3°C / sec or less, or ±0.2°C / sec or less, and although there is no lower limit, it may be substantially ±0.01°C / sec or more, more substantially ±0.05°C / sec or more.

[0103] By making the thermal block satisfy the above formula 3, the efficiency of the gene amplification reaction can be improved, and the reliability of the PCR thermal cycler can be ensured even in ultra-high speed PCR reactions.

[0104] The difference in cooling rate between region A and region B may be similar to or the same as the difference in heating rate between region A and region B. Here, the cooling rate may be the ratio (ΔT / Δs) of the temperature change (ΔT) measured from the initial temperature to the time change (Δs) calculated by measuring the temperature in region A and region B after 15 seconds when the temperature is lowered from 95°C to 25°C using a heating element.

[0105] In one embodiment, the absolute value of the ramping rate of the PCR thermal cycler may be 3.0°C or greater.

[0106] Specifically, the ramp-up and ramp-down rates of a PCR thermal cycler can be different, each independently.

[0107] As an example, the temperature rise rate of the PCR thermal cycler may be 3.0°C or higher, specifically 3.5°C or higher, more specifically 3.8°C or higher, and although there is no upper limit, it may be 10°C or lower, or substantially 8°C or lower.

[0108] Unlike the rising rate of the PCR thermal cycler described above, the falling rate of the PCR thermal cycler has a negative value. Although it has a negative value, the falling rate of the PCR thermal cycler may be 3.0°C or higher, specifically 3.05°C or higher, more specifically 3.08°C or higher, based on the absolute value. The upper limit may be, but is not limited to, 8°C or lower, or substantially 6°C or lower.

[0109] It goes without saying that a PCR thermal cycler may include, in addition to the heating element and heat block described above, conventional components known in the art, such as a control device, an optical system, a fluorescence detection device, an analytical device, and the like.

[0110] Hereinafter, the composite material for a thermal cycler heat block and a heat block including the same according to the present invention will be described in more detail with reference to the following examples. However, the following examples are merely a reference for explaining the present invention in detail, and the present invention is not limited thereto and may be embodied in various forms.

[0111] Furthermore, unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used in the description herein are merely for the purpose of effectively describing particular embodiments and are not intended to limit the present invention.

[0112] (Production Example 1) A 5L flask was charged with 1200ml of water (ultrapure water) and 15.0g of the copper nanowires prepared according to the above Preparation Example, and the mixture was stirred at 10,000 rpm using a homomixer (K-Corporation, Primix). To remove the oxide film from the copper nanowires, 22.5g of ethylenediaminetetraacetic acid disodium salt (EDTA-2Na Dihydrate, SAMCHUN Pure Chemical Industries) was dissolved in 150ml of water (ultrapure water) and added, and the mixture was stirred at 10,000 rpm for 3 minutes. 13.1g of L-ascorbic acid (C6H8O6, SAMCHUN Pure Chemical Industries), a reducing agent, was dissolved in 150ml of water (ultrapure water) and added, and the mixture was stirred for another 3 minutes.

[0113] To apply a primary silver coating to the copper nanowires from which the oxide film had been removed, 150 ml of water (ultrapure water) and 1.67 g of silver nitrate (AgNO3, JUNTECH) were mixed to prepare a first silver nitrate solution, which was then added at a rate of 10 ml per minute using a peristaltic pump (Leadfluid, BT100L) for approximately 15 minutes to react.

[0114] Next, the sample with the primary silver coating completed was washed with 2 L of water (ultrapure water) and dried to obtain a primary silver-coated copper nanowire sample.

[0115] Next, for the secondary silver coating, the sample with the primary silver coating completed and 1200 ml of water (ultrapure water) were placed in a 5 L flask and stirred at 10,000 rpm using a homomixer (K-Corporation, Primix).To steadily remove copper ions, 22.5 g of ethylenediaminetetraacetic acid disodium salt (EDTA-2Na Dihydrate, SAMCHUN Pure Chemical Industries) was dissolved in 150 ml of water (ultrapure water) and added, and the mixture was stirred at 10,000 rpm for 3 minutes.

[0116] 21g of the reducing agent, potassium sodium stannate tetrahydrate (KNaC4H4O6·4H2O), was dissolved in 150ml of water (ultrapure water) and added, followed by stirring for another 3 minutes. For the secondary silver coating, 4.23g of silver nitrate was added to 655ml of water (ultrapure water) to prepare a silver nitrate solution, and then 4.34ml of ammonia water (NH4OH, SAMCHUN Pure Chemical) was added to prepare a secondary silver nitrate-ammonia complex solution. The secondary silver-ammonia complex solution was added at a rate of 10ml per minute and allowed to react for approximately 66 minutes.

[0117] After the reaction was completed, the metal nanowires were separated using filter paper, washed with 2 L of water (ultrapure water), and dried at room temperature for 24 hours to obtain copper nanowires with a thin, uniform silver coating.

[0118] The length and thickness of the obtained silver-coated copper nanowires were analyzed, and the length was measured to be 2.1–6.3 μm and the thickness to be 191–450 nm.

[0119] In addition, the Ag 3d calculated from the XPS spectrum obtained by X-ray photoelectron spectroscopy (XPS, Thermo VG Scientific, Sigma Probe) on the surface of the silver-coated copper nanowires. 5 / 2 Peak intensity I1 and Cu 2p 3 / 2 As a result of comparing the peak intensities I2 and I1, it was confirmed that I2 / I1 was 0.029.

[0120] (Production Example 2) The same procedure as in Preparation Example 1 was carried out, except that the primary silver coating reaction was not performed and instead a secondary silver coating was performed by adding 655 ml of water (ultrapure water) to 12.2 g of silver nitrate to prepare a silver nitrate solution, and then adding 4.34 ml of ammonia water (NHOH, SAMCHUN Pure Chemicals) to the solution, and a silver coating layer was formed on the copper nanowires using only the secondary silver-ammonia complex solution.

[0121] Here, Ag 3d calculated from the XPS spectrum 5 / 2 Peak intensity I1 and Cu 2p 3 / 2As a result of comparing the peak intensities I2 and I1, it was confirmed that I2 / I1 was 0.41.

[0122] Example 1 Tin powder (average particle size 100 μm) and the silver-coated copper nanowires prepared in Preparation Example 1 were mixed in a weight ratio of 99.5:0.5, and approximately 130 g of the mixture was placed in a high-speed fluid mixer (HSFM-10-S, ESYN Machinery) and mixed at 500 rpm for 10 minutes twice.

[0123] Approximately 130 g of the mixture (composite material) prepared above was placed between the upper and lower punches of a graphite mold (internal center diameter 40.0 mm), and the mold containing the mixture was placed between the vertical presses in a high-temperature press (D1P-20J, DAEHEUNG Science), and then pressurized with a hydraulic cylinder to perform melt molding at 260°C.

[0124] The processing steps for producing a molded article (heat block) using a composite material containing tin powder and silver-coated copper nanowires are shown schematically in Figure 1 .

[0125] The specimen containing the formed tin- and silver-coated copper nanowires was subjected to non-destructive testing using an ultrasonic flaw detector (SISTSCAN 500, KYUNGDO YANGHAENG Co., Ltd.). As a result, it was confirmed that the specimen containing the formed tin- and silver-coated copper nanowires was melt-formed without any pores or defects.

[0126] The molding was performed under the conditions of a melt temperature of 260°C and a maintenance time of 30 minutes. The sintered molded product was analyzed using a thermal diffusion measurement device (Xenon Flash Instrument LFA 447, NETZSCH), and the results of the thermal analysis are summarized in Table 1 below.

[0127] (Examples 2 to 6) The same procedure as in Example 1 was carried out, except that the mixing ratio of tin powder to silver-coated copper nanowires was 99:1 (Example 2), 98.5:1.5 (Example 3), 98:2 (Example 4), 97.5:2.5 (Example 5), and 97:3 (Example 6). The results of the thermal analysis of each sintered molded product are summarized in Table 1 below, and non-destructive testing was carried out on the molded test piece of Example 3. The results of the non-destructive testing of Example 3, similar to the results of Example 1, confirmed that the molded test piece containing tin and silver-coated copper nanowires was melt-molded without pores or defects.

[0128] Example 7 The same procedure as in Example 3 was carried out, except that the silver-coated copper nanowires produced in Production Example 2 were used. The results of the thermal analysis of the sintered molded product are summarized in Table 1 below.

[0129] Example 8 The same procedure as in Example 3 was carried out, except that the tin powder and silver-coated copper nanowires were mixed using a mortar instead of a high-speed fluid mixer. The results of the thermal analysis of the sintered molded product are summarized in Table 1 below.

[0130] Non-destructive testing of specimens molded using a mixture of tin powder and silver-coated copper nanowires in a mortar revealed that, unlike the results of Examples 1 and 3, the specimens containing molded tin and silver-coated copper nanowires had pores and defects greater than the standard value.

[0131] (Comparative Example 1) The same procedure as in Example 1 was carried out except that tin powder was used alone. The results of thermal analysis of the sintered molded product are summarized in Table 1 below.

[0132] (Comparative Example 2) The same procedure as in Example 3 was carried out except that a mixture of tin powder and silver powder was used. The results of thermal analysis of the sintered molded product are summarized in Table 1 below.

[0133] [Table 1]

[0134] Referring to Table 1, it can be seen that Example 3 had the best thermal conductivity properties, and the test specimen manufactured using the composite material in which tin powder and silver-coated copper nanowires were mixed had improved thermal conductivity properties compared to the test specimen manufactured using tin powder alone (Comparative Example 1) and the composite material in which tin powder and silver powder were mixed (Comparative Example 2).

[0135] Furthermore, by comparing the thermal conductivity characteristics of Examples 3 and 7, it was confirmed that the surface characteristics of the silver-coated copper nanowires contained in the composite material affect the thermal conductivity characteristics.

[0136] Specifically, the Ag 3d calculated from the XPS spectrum 5 / 2 Peak intensity I1 and Cu 2p 3 / 2 Based on the ratio of peak intensities I2 (I2 / I1) of the peak intensities I1 and I2 of the composite material of Example 3, which includes silver-coated copper nanowires in which the silver coating layer located on the copper nanowires is uniformly and densely formed, it can be seen that the thermal conductivity properties of the molded product made using the composite material of Example 7, which includes silver-coated copper nanowires in which the silver is not uniformly coated and some of the copper is exposed, are superior to the thermal conductivity properties of the molded product made using the composite material of Example 7.

[0137] (Experimental example) Confirmation of heat transfer characteristics In order to confirm the heat transfer properties of the manufactured test pieces, the molded products of Examples 1, 3, 7 and Comparative Examples 1 and 2 were attached onto a Peltier element, and the heat transfer properties were confirmed.

[0138] Here, a voltage was applied to the Peltier element to raise the temperature of the molded product to 95°C, and the temperatures of the 0.2t (area A) and 0.8t (area B) parts of the molded product's total height t, based on the contact surface of the molded product that comes into contact with the Peltier element, were simultaneously measured, both before and 15 seconds after the voltage was applied. The temperature change over 15 seconds in each area was defined as the heating rate, and the heat transfer properties of each molded product were compared. The results are summarized in Table 2 below.

[0139] [Table 2]

[0140] Referring to Table 2, in Examples 1, 3, and 7, it was observed that there was almost no deviation in the heating rate between the region near the adhesive surface of the molded article attached to the Peltier element (region A) and the region located relatively far from the adhesive surface (region B), whereas in Comparative Examples 1 and 2, it was observed that there was a large deviation in the heating rate of 0.6°C or more in each region.

[0141] In addition, we calculated and compared the cooling rate when the direction of the current in the Peltier element was reversed and the temperature was changed from 95°C to 25°C using the same method as the heating rate described above, and confirmed that the results were almost similar.

[0142] It was found that the molded product manufactured using a composite material containing a mixture of tin powder and silver-coated copper nanowires has almost no deviation in heating and cooling rates between the area in direct contact with the heat source and the area located away from the heat source, indicating that the heat transfer efficiency of the molded product is significantly superior. It was also found that the molded product can be used as a heat block in a PCR thermal cycler to improve the efficiency of gene amplification reactions and ensure the reliability of ultra-fast PCR reactions.

[0143] Furthermore, a PCR thermal block having the shape shown in Figure 5 was fabricated by casting at 260°C using the composite material of Example 3. The fabricated PCR thermal block was installed in a Real Time PCR device (ExiCycler, Bioneer) and its thermal properties were measured.

[0144] Here, the PCR reaction temperature was 95°C, and the temperature was increased from 25°C to 95°C and decreased from 95°C to 25°C. The increase and decrease speeds of the PCR cycler were measured three times each, comparing them with a PCR cycler using a conventional aluminum PCR heat block. The analysis results are summarized in Table 3 below.

[0145] [Table 3]

[0146] As can be seen from Table 3, the PCR thermal cycler using the PCR thermal block manufactured using a composite material that combines tin powder and silver-coated copper nanowires showed an average increase rate of 28.2% and an average decrease rate of 32.3%, which were superior to the case using an aluminum PCR thermal block.

[0147] As described above, the present invention has been described using specific matters and limited examples, but this is provided to facilitate a more general understanding of the present invention, and the present invention is not limited to the above examples. Those skilled in the art will appreciate that various modifications and variations can be made from such descriptions.

[0148] Therefore, the concept of the present invention should not be limited to the above-described embodiments, and all modifications equivalent to or equivalent to the scope of the claims, as well as the scope of the claims described below, can be said to fall within the scope of the concept of the present invention.

Claims

1. a powdered metal that is a first metal or an alloy that includes the first metal; and a metal nanowire having a core-shell structure in which a shell containing a third metal is located on a core containing a second metal.

2. 2. The composite material for a heat block of a thermal cycler according to claim 1, wherein the first metal is tin, and the alloy is one or more selected from the group consisting of tin-silver, tin-copper, tin-aluminum, tin-bismuth, tin-antimony, tin-copper-bismuth, tin-silver-bismuth, tin-copper-antimony, tin-silver-antimony, tin-copper-silver, tin-copper-silver-antimony, and tin-copper-silver-bismuth.

3. 2. The composite material for a heat block of a thermal cycler of claim 1, wherein the second metal is copper and the third metal is silver or gold.

4. The composite material for a heat block of a thermal cycler according to claim 3 , wherein the metal nanowires are silver-coated copper nanowires.

5. The metal nanowires were identified as silver (Ag 3d) in the X-ray photoelectron spectroscopy spectrum. ５／２ Peak intensity I １ and copper Cu 2p ３／２ Peak intensity I ２ 5. The composite material for a heat block of a thermal cycler according to claim 4, wherein the composite material satisfies the following formula 1: (Formula 1) I ２ / I １ ≦0.2

6. 2. The composite material for a heat block of a thermal cycler according to claim 1, wherein the metal nanowires have a diameter of 100-500 nm and an aspect ratio of 5-100.

7. The particle size D of the powder metal ｐ : diameter D of metal nanowire ｗ The ratio (D ｐ / D ｗ 2. The composite material for a heat block of a thermal cycler according to claim 1, wherein the ratio of the ionic liquid to the polymer is 1:0.0001 to 0.

01.

8. 2. The composite material for a heat block of a thermal cycler according to claim 1, wherein the weight ratio of the powder metal to the metal nanowires is 1:0.001-0.

1.

9. A low specific heat heat block for a thermal cycler, manufactured by sintering, casting, rolling or casting the composite material according to any one of claims 1 to 8.

10. tin or a tin alloy; A low specific heat heat block for a thermal cycler, comprising silver-coated copper nanowires.

11. 11. The low specific heat heat block of a thermal cycler according to claim 10, wherein the weight ratio of the tin or tin alloy to the silver-coated copper nanowires is 1:0.001-0.

1.

12. The silver-coated copper nanowires were found to be Ag 3d in X-ray photoelectron spectroscopy. ５／２ Peak intensity I １ and copper Cu 2p ３／２ Peak intensity I ２ 11. The low specific heat heat block of a thermal cycler of claim 10, wherein: (Formula 1) I ２ / I １ ≦0.2

13. 11. The low specific heat heat block of a thermal cycler according to claim 10, wherein the thermal conductivity of the heat block is 70 to 100 W / (m·K) at 21°C.

14. A heating element; a heat block having one end contacting one surface of the heating element and having an insertion hole at another end positioned opposite the one end, A PCR (Polymerase Chain Reaction) thermal cycler, wherein the thermal block is formed by sintering, casting, rolling, or casting the composite material according to any one of claims 1 to 8.

15. 15. The PCR thermal cycler of claim 14, wherein the heat block satisfies the following formula 2: (Formula 2) H ａ -H ｂ ≦±0.5℃ / sec (In formula 2, H ａ is the heating rate in the 0.1 to 0.3t region, defined as region A, based on one end of the heat block that is in contact with one surface of the heating element, and H ｂ is the heating rate in the 0.7t to 1.0t region, which is defined as region B.)

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