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EP-4737885-A1 - DETECTING KIT, DETECTING DEVICE, AND DETECTING METHOD FOR DETECTING TRACE AMOUNT OF HEAVY METAL IN SAMPLE

EP4737885A1EP 4737885 A1EP4737885 A1EP 4737885A1EP-4737885-A1

Abstract

An object is to provide a detection kit and a detection device for detecting a trace amount of a heavy metal contained in water, soil, a food ingredient, a food product or the like rapidly, highly sensitively, and selectively by a simple method in or around a spot such as a water source, a farmland, or a food processing plant, and a detection method using these. The present invention provides a detection kit, for detecting a trace amount of a heavy metal in a sample, including a DNA aptamer labeled with a fluorescent molecule, and specifically binding to a heavy metal. The heavy metal contained in the sample may be selected from cadmium, mercury, and arsenic. The detection may be performed by visual observation, fluorescence analysis, or fluorescence polarization analysis.

Inventors

  • TAKAMURA, TAKEJI
  • OTA, MIKI
  • AOYAGI, TETSUJI

Assignees

  • Aoyagi, Tetsuji

Dates

Publication Date
20260506
Application Date
20240701

Claims (12)

  1. A detection kit for detecting a trace amount of a heavy metal in a sample, comprising a DNA aptamer that is labeled with a fluorescent molecule, and selectively binds to a specific heavy metal.
  2. The detection kit according to claim 1, wherein the heavy metal is at least one selected from the group consisting of cadmium, mercury, and arsenic.
  3. The detection kit according to claim 1, wherein detection is performed by visual observation, fluorescence analysis, or fluorescence polarization analysis.
  4. The detection kit according to claim 1, wherein the sample is water, soil, a food ingredient, or a food product.
  5. The detection kit according to claim 1, wherein the DNA aptamer is labeled with two fluorescent molecules.
  6. The detection kit according to claim 1, further comprising MOPS buffer, HEPES buffer, or a carbonate-bicarbonate buffer.
  7. A detection device comprising: a DNA aptamer that is labeled with a fluorescent molecule, and selectively binds to a specific heavy metal; and a fluorescence measurement unit for measuring fluorescence intensity of the fluorescent molecule of the DNA aptamer, wherein a trace amount of the heavy metal in a sample is detected by measuring fluorescence intensity or fluorescence polarization intensity derived from the fluorescent molecule labeling the DNA aptamer bound to the specific heavy metal.
  8. The detection device according to claim 7, wherein the heavy metal is at least one selected from the group consisting of cadmium, mercury, and arsenic.
  9. The detection device according to claim 7, wherein detection of the heavy metal is performed by fluorescence analysis or fluorescence polarization analysis.
  10. The detection device according to claim 7, wherein the sample is water, soil, a food ingredient, or a food product.
  11. A detection method for detecting a trace amount of a heavy metal in a sample, comprising the steps of: obtaining a mixed solution by mixing a solution, in which a DNA aptamer labeled with a fluorescent molecule and specifically binding to the specific heavy metal is dissolved, with a liquid containing a sample potentially containing the specific heavy metal; measuring fluorescence intensity or fluorescence polarization intensity derived from the fluorescent molecule of the DNA aptamer contained in the mixed solution; and detecting the specific heavy metal based on a result of the measurement.
  12. The detection method according to claim 11, wherein the step of measuring fluorescence polarization intensity further comprises a step of measuring a concentration of the heavy metal.

Description

[Technical Field] The present invention relates to a detection kit, a detection device, and a detection method for detecting a trace amount of a heavy metal in a sample. [Background Art] It has been conventionally known that problems are caused by heavy metals contained in water and soil at construction sites and farmlands. For example, when a heavy metal is present in water or soil of rice paddies or vegetable farms, the heavy metal accumulates in the cultivated crops, such as rice and vegetables. By ingesting these crops, or ingesting heavy-metal-containing groundwater as drinking water, the heavy metal is taken into human body. Similar problems also arise due to pesticides and impurities contained in food ingredients and food products. When the ingested heavy metal is toxic, serious adverse effects are caused on health. Heavy metals such as cadmium, mercury, and arsenic can cause acute or chronic symptoms in the human body, including developmental disorders in children, issues during pregnancy, damage to the liver, kidneys, intestines and the like, anemia, and the onset of cancer. Cadmium, mercury, and arsenic are consistently among the top ten chemical substances of major public health concern listed by the World Health Organization. Moreover, cadmium and related compounds thereof are currently listed in Group A of the IARC classification as causes of human cancer. Many conventional methods for testing heavy metals in water and soil involve time-consuming detection, or use expensive equipment that must be handled carefully for detecting heavy metals. PTL 1 discloses a hazardous substance content analysis method for measuring the content of hazardous substances, such as heavy metals eluted from soil, using an X-ray fluorescence analyzer. PTL 2 discloses a method in which a chelate complex is created by adding a chelating agent to a test solution obtained from soil, and is subjected to X-ray fluorescence analysis. Although cadmium can be detected by several instrumental analysis techniques using an atomic absorption spectrometry and an inductively coupled plasma device, these techniques are known to have relatively high initial and running costs (NPLs 1 and 2). In addition, many conventional detection methods require large, expensive equipment and trained operators. [Citation List] [Patent Literature] [PTL 1] the Publication of Japanese Patent No. 4647405[PTL 2] Japanese Unexamined Patent Application, Publication No. 2004-294329 [Non Patent Literature] [NPL 1] Chen K, Mou P, Zhu A, Chen P, Chen J, Gao G, Wang X, Feng X, Yu C (2023) Environmental Monitoring and Assessment 195.[NPL 2] Pyle SM, Nocerino JM, Deming SN, Palasota JA, Palasota JM, Miller EL, Hillman DC, Kuharic CA, Cole WH, Fitzpatrick PM, Watson MA, Nichols KD (1996) Environmental Science & Technology 30:204-213. [Summary of Invention] [Technical Problem] Considering the above-described problems, if the presence of heavy metals in water or soil can be rapidly ascertained by a simple method near water sources, farmlands, or food processing plants, measures, such as quickly cleaning contaminated water or soil, or halting product shipment, can be taken. For example, a simple method for detecting a lower concentration (lower than 10-10 mol/L) of a heavy metal in water is desired, but has not yet been achieved. There is a strong demand for a system for rapidly, inexpensively, and simply detecting a trace amount of a heavy metal in an environment such as water or soil. The present invention has been made in view of these circumstances, and an object is to provide a detection kit, a detection device, and a detection method for highly sensitively and rapidly detecting, near water sources, farmlands, or food processing plants, a trace amount of a heavy metal in water, soil, food ingredients, and food products by a simple technique. [Solution to Problem] In order to solve the aforementioned problems, a detection kit, a detection device, and a detection method for detecting a trace amount of a heavy metal in a sample of the present invention employ the following solutions: A first aspect of the present invention provides a detection kit for detecting a trace amount of a heavy metal in a sample, including a DNA aptamer that is labeled with a fluorescent molecule, and selectively binds to a specific heavy metal. In the first aspect, the heavy metal may be at least one selected from the group consisting of cadmium, mercury, and arsenic. In the first aspect, detection may be performed by visual observation, fluorescence analysis, or fluorescence polarization analysis. In the first aspect, the sample may be water, soil, a food ingredient, or a food product. In the first aspect, the DNA aptamer may be labeled with two fluorescent molecules. The first aspect may further include MOPS buffer, HEPES buffer, or a carbonate-bicarbonate buffer. A second aspect of the present invention provides a detection device including: a DNA aptamer that is labeled with a fluoresc