US-12625082-B2 - Optical detection chip and optical detection system

US12625082B2US 12625082 B2US12625082 B2US 12625082B2US-12625082-B2

Abstract

Provided is an optical detection chip that makes it possible to accurately measure, in a short time, hydrogen sulfide and methyl mercaptan contained in a gas subject to detection. An optical detection chip is provided with: an optically transparent substrate; and a layer structure provided with a pigment layer that is formed on the optically transparent substrate, that includes organic pigment molecules containing amino groups, ketone groups, or quinones, as well as metal ions of at least one kind selected from the group consisting of Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg, Ag, Pb, and Tl, and that exhibits a color change in response to a gas subject to detection including at least one of hydrogen sulfide and methyl mercaptan.

Inventors

Seung-Woo Lee
Kiyoshi Hirakawa
Hirofumi Okuda

Assignees

THE UNIVERSITY OF KITAKYUSHU
TOYOKO KAGAKU CO., LTD.

Dates

Publication Date: 20260512
Application Date: 20220809
Priority Date: 20210811

Claims (13)

1 . An optical detection chip comprising: a translucent substrate; and a layer structure formed on the translucent substrate and comprising a dye layer, the dye layer comprising an organic dye molecule comprising an amino group, a ketone group, or a quinone, and any one or two metal ions selected from the group consisting of Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg, Ag, Pb and Tl, and the dye layer capable of changing color by reacting with a gas subject to detection comprising at least one of hydrogen sulfide or methyl mercaptan.
2 . The optical detection chip according to claim 1 , wherein the organic dye molecule is 2,6-dichloroindophenol, methylene blue, bromothymol blue, methyl red, or neutral red.
3 . The optical detection chip according to claim 1 , wherein the translucent substrate is an acrylic resin, a styrene resin, a polyethylene terephthalate resin, a polycarbonate resin, a polypropylene resin, or glass.
4 . The optical detection chip according to claim 1 , wherein the layer structure comprises a particle layer formed of charged particles having an average particle diameter of 10 to 100 nm between the translucent substrate and the dye layer.
5 . The optical detection chip according to claim 4 , wherein the charged particles comprise at least one type of inorganic particles selected from the group consisting of titania, silica, and alumina, or at least one type of resin particles selected from the group consisting of an acrylic resin, a styrene resin, a fluororesin, and a silicone resin.
6 . The optical detection chip according to claim 4 , wherein the layer structure further comprises an organic compound layer formed of an organic compound.
7 . The optical detection chip according to claim 6 , wherein the organic compound layer is formed of at least one cationic organic compound selected from the group consisting of polyethyleneimine, polyallylamine hydrochloride, polydiallyldimethylammonium chloride, chitosan, polyvinyl pyridine, and polylysine, or at least one anionic organic compound selected from the group consisting of polystyrene sulfonate, polyvinyl sulfate, dextran sulfate, chondroitin sulfate, polyacrylic acid, polymethacrylic acid, polymaleic acid, and polyfumaric acid.
8 . The optical detection chip according to claim 1 , wherein the optical detection chip is made of a flat plate material having a curved surface portion that reflects light beams entering the translucent substrate, and wherein the layer structure is formed on the curved surface portion.
9 . The optical detection chip according to claim 1 for use in detection of hydrogen sulfide or methyl mercaptan comprised in the gas subject to detection.
10 . An optical detection system for measuring a concentration of a gas subject to detection comprising at least one of hydrogen sulfide or methyl mercaptan, the system comprising: a dehumidifying filter that removes moisture from outside air to be introduced to produce dry gas; a sealed container that encloses the gas subject to detection that has been collected; a pusher block and a motor that transports the gas subject to detection from the sealed container; electromagnetic valves that switch a first passage to a second passage, and first and second optical detection devices each comprising a light-emitting diode and a photodiode, wherein in the first passage, the gas subject to detection is passed through a first filter that removes ammonia and phenol and the resulting gas subject to detection is brought into contact with a curved surface portion of a first optical detection chip and, in the second passage, the gas subject to detection is passed through a second filter that removes ammonia, phenol, and hydrogen sulfide and the resulting gas subject detection is brought into contact with a curved surface portion of a second optical detection chip.
11 . The optical detection system according to claim 10 , wherein the first and second optical detection chips comprise: a translucent substrate; and a layer structure formed on the translucent substrate and comprising a dye layer, the dye layer comprising an organic dye molecule comprising an amino group, a ketone group, or a quinone, and any one or two metal ions selected from the group consisting of Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg, Ag, Pb and Tl, and the dye layer capable of changing color by reacting with a gas subject to detection comprising at least one of hydrogen sulfide or methyl mercaptan.
12 . The optical detection system according to claim 10 , wherein the optical detection device measures a change in color of the layer structure.
13 . The optical detection system according to any one of claim 10 , wherein the first filter comprises calcium acetate and the second filter comprises calcium acetate and zinc sulfate.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This is the U.S. national stage of application No. PCT/JP2022/030443, filed on Aug. 9, 2022. Priority under 35 U.S.C. § 119 (a) and 35 U.S.C. § 365(b) is claimed from Japanese Application No. 2021-131390, filed Aug. 11, 2021, the disclosure of which is also incorporated herein by reference. TECHNICAL FIELD The present invention relates to an optical detection chip and an optical detection system. BACKGROUND ART In recent years, in the field of medicine and health, detection methods using gases subject to detection have been developed, such as those detecting a cause of an infectious disease represented by influenza by detecting various viruses contained in an oral gas, those detecting hydrogen sulfide, methyl mercaptan, and dimethyl sulfide contained in an oral gas and indicating concentrations of the above-described oral gas components, and those diagnosing asthma by detecting nitric oxide (NO) contained in an exhaled gas. However, since an oral gas, which is one of the gases subject to detection, contains numerous types of volatile organic compounds such as ammonia, phenol, ethyl alcohol, trimethylamine, and acetone, in addition to hydrogen sulfide, dimethyl sulfide, and methyl mercaptan, it is difficult to measure them separately. For this reason, it has been difficult for analyses of the gases subject to detection including the oral gases to be put to practical use. On the other hand, layer structures for capturing changes in electrical, magnetic, chemical, and optical properties by forming a thin layer on a substrate and placing a specific compound in the thin layer have been known. Patent Document 1 discloses an atmospheric sensor including a portion in which a cationic compound film and an anionic compound film are alternately laminated multiple times on the surface of a core-exposed portion formed on a portion of a clad of an optical fiber or an optical waveguide. Patent Document 1 provides the atmospheric sensor that is compact and lightweight and yet capable of detecting gas and humidity with high sensitivity. Patent Document 2 discloses a particulate film formed by the adsorption of particulates on the surface of a carrier and an organic compound film formed by the adsorption of an organic compound. Patent Document 2 expands a surface area of the organic compound film to which a certain molecule is adsorbed and provides a sensor with high sensitivity with a small number of layers. In Non-Patent Document 1, a hydrogen sulfide gas in an oral gas is analyzed by adding a copper (Cu) ion to a reagent for a colorimetric analysis, including 2,6-dichloroindophenol (hereinafter referred to as “DCIP”) and fixing them to a silica gel support. However, Non-Patent Document 1 does not disclose any information regarding the distinction between hydrogen sulfide and methyl mercaptan. Furthermore, Non-Patent Document 1 has problems because it is time-consuming since measurement is based on an attenuated total reflection (ATR) method. That measurement results are unreliable due to a significant influence of humidity. Moreover, an analysis of an oral gas, which is one of the gases subject to detection, has problems in that measurement is time-consuming since only a small amount of the oral gas can be collected, and the oral gas contains numerous types of gases. In particular, there is a problem that an oral gas resulting from a periodontal disease is difficult to measure accurately since the oral gas varies significantly from person to person and only a minute amount of the oral gas can be collected. CITATION LIST Non-Patent Document Non-Patent Document 1: Julio Rodriguez-Fernandez, Rosario Pereiro, Alfredo Sanz-Medel “Optical fiber sensor for hydrogen sulfide monitoring in mouth air” Analytica Chimica Acta, 2002, 471.1:13-23 Patent Document Patent Document 1: Japanese Patent No. 5219033Patent Document 2: Japanese Patent No. 5388309 DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention Therefore, the object of the present invention is to provide an optical detection chip that can accurately measure hydrogen sulfide and methyl mercaptan contained in a gas subject to detection in a short time. Furthermore, another object of the invention is to provide an optical detection system, including an optical detection chip configured to separate an ammonia gas and phenol from a gas subject to detection and measure amounts of hydrogen sulfide and methyl mercaptan. Means for Solving the Problems Features of the invention, which are means to solve the above problems, will be described below. (1) An optical detection chip including: a translucent substrate; and a layer structure formed on the translucent substrate and including a dye layer, the dye layer including an organic dye molecule including an amino group, a ketone group, or a quinone, and any one or two metal ions selected from the group consisting of Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg, Ag, Pb and Tl, and the dye layer capa