Method for detecting toxic metal ions in sample

Patent metadata

Field	Value
Publication number	US-10254268-B2
Application number	US-201715465344-A
Country	US
Kind code	B2
Filing date	Mar 21, 2017
Priority date	Mar 22, 2016
Publication date	Apr 9, 2019
Grant date	Apr 9, 2019

Abstract

Disclosed is a method for detecting toxic metal ions in a sample. The method includes: a) preparing a solution of organic acid-bound gold nanoparticles; b) adding a sample containing toxic metal ions to the solution prepared in a) to allow the gold nanoparticles to aggregate; c) dropping the reaction solution obtained in b) onto a silicon substrate and drying the reaction solution such that the gold nanoparticle aggregates are immobilized on the silicon substrate; and d) analyzing the characteristics of the gold nanoparticles immobilized on the silicon substrate. The method enables the detection of even a trace amount of toxic metal ions in a sample with high sensitivity. Therefore, the method can be applied to the management of water quality in food service providers and hospitals, the measurement of contaminants in water supply and drainage systems, and the management of industrial wastewater. Furthermore, the method is expected to be widely applicable to water purifiers and the food and beverage industry in the future.

First claim

What is claimed is:

1. A method for detecting toxic metal ions in a sample, comprising:
a) preparing a solution of organic acid-bound gold nanoparticles;
b) adding a sample containing toxic metal ions to the solution prepared in a) to form a reaction solution and to allow the gold nanoparticles to aggregate in the reaction solution;
c) dropping the reaction solution obtained in b) onto a silicon substrate and drying the reaction solution such that a gold nanoparticle aggregate is immobilized on the silicon substrate to form a sample substrate;
d) measuring a height of the gold nanoparticle aggregate immobilized on the sample substrate by atomic force microscopy; and
e) detecting the toxic metal ions in the sample by comparing the height of the gold nanoparticle aggregate immobilized on the sample substrate with a height of a gold nanoparticle aggregate immobilized on a control substrate prepared from a control without the toxic metal ions.

2. The method according to claim 1 , wherein the organic acid is selected from the group consisting of citric acid, cytosine, thymine, and mixtures thereof.

3. The method according to claim 1 , wherein the toxic metal ions are ions of at least one metal selected from the group consisting of aluminum, mercury, silver, and copper.

4. The method according to claim 1 , wherein the gold nanoparticles are allowed to aggregate at room temperature for 1.5 hours to 3 hours.

5. The method according to claim 1 , wherein a concentration of the toxic metal ions in the sample is less than 1 μM.

6. A method for detecting toxic metal ions in a sample, comprising:
a) preparing a solution of organic acid-bound gold nanoparticles;
b) adding a sample containing toxic metal ions to the solution prepared in a) to form a reaction solution and to allow the gold nanoparticles to aggregate in the reaction solution;
c) dropping the reaction solution obtained in b) onto a silicon substrate and drying the reaction solution such that a gold nanoparticle aggregate is immobilized on the silicon substrate to form a sample substrate;
d) measuring a surface potential of the gold nanoparticle aggregate immobilized on the sample substrate by Kelvin probe force microscopy; and
e) detecting the toxic metal ions in the sample by comparing the surface potential of the gold nanoparticle aggregate immobilized on the sample substrate with a surface potential of a gold nanoparticle aggregate immobilized on a control substrate prepared from a control without the toxic metal ions.

7. The method according to claim 6 , wherein the organic acid is selected from the group consisting of citric acid, cytosine, thymine, and mixtures thereof.

8. The method according to claim 6 , wherein the toxic metal ions are ions of at least one metal selected from the group consisting of aluminum, mercury, silver, and copper.

9. The method according to claim 6 , wherein the gold nanoparticles are allowed to aggregate at room temperature for 1.5 hours to 3 hours.

10. The method according to claim 6 , wherein a difference between the surface potential of the gold nanoparticle aggregate immobilized on the sample substrate and the surface potential of the gold nanoparticle aggregate immobilized on the control substrate increases in proportion to the concentration of the toxic metal ions in the sample.

11. The method according to claim 6 , wherein a concentration of the toxic metal ions in the sample is less than 1 μM.

Assignees

• Univ Korea Res & Business Foundation Sejong Campus

Inventors

• Park Jinsung
• Kim Woong
• Park Joohyung
• Jo Seongjae
• Kim Minwoo
• Lee Gyudo

Classifications

• G01N1/28

  Preparing specimens for investigation {including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q}(mounting specimens on microscopic slides G02B21/34; means for supporting the objects or the materials to be analysed in electron microscopes H01J37/20 {; laboratory gas handling apparatus B01L5/00}) · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• G01N2015/0038

  Investigating nanoparticles · CPC title

• B82Y15/00

  Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors · CPC title

• G01N33/20 Primary

  Metals · CPC title