Immunochromatography Detection Sensor Comprising Optical Waveguide and a Detection Method Using the Same

Abstract

The present invention relates to an immunochromatographic detection sensor comprising optical waveguides and a detection method using the same, and more particularly, to an immunochromatographic detection sensor comprising optical waveguides, in which the optical waveguides are provided under the membrane, probe beams transmitted through the optical waveguide maximize the interaction frequency between evanescent wave generated on the surface of optical waveguide and the colored conjugate in the band formed on the membrane, and thus the absorbance signal from the colored conjugate is greatly amplified to improve the sample detection sensitivity, and a detection method using the same.

1 . A lateral flow membrane-based immunochromatographic detection sensor comprising
 (a) a substrate that is provided under the membrane; and   (b) optical waveguides that are adhered to the bottom portion of the membrane,   wherein the immunochromatographic detection uses the light that is transmitted through the optical waveguide as probe beam.   
     
     
         2 . The immunochromatographic detection sensor according to  claim 1 , wherein a colored conjugate band, which absorbs the energy of the evanescent wave that is generated at the interface between the membrane and the optical waveguide is formed on the membrane, while the probe beam is transmitted through the optical waveguide. 
     
     
         3 . The immunochromatographic detection sensor according to  claim 2 , wherein the amount of the colored conjugate is determined by the intensity of the output probe beam, so as to analyze the component of analyte in the sample. 
     
     
         4 . The immunochromatographic detection sensor according to  claim 1 , wherein the membrane is made of one or more selected from the group consisting of nitrocellulose, glass fiber, polyethylene, polycarbonate, and polystyrene. 
     
     
         5 . The immunochromatographic detection sensor according to  claim 1 , wherein the membrane has a thickness in the range of 1˜100 μm. 
     
     
         6 . The immunochromatographic detection sensor according to  claim 1 , wherein the substrate is made of any one selected from glass, quartz, alumina (Al 2 O 3 ), PMMA (polymethylmethacrylate), PS (polystyrene), COC (cyclic olefin copolymer), and silicone. 
     
     
         7 . The immunochromatographic detection sensor according to  claim 6 , wherein the substrate is coated with a SiO 2  thin film having a thickness in the range of 300˜1000 nm as an underlayer, if the substrate is a silicon substrate. 
     
     
         8 . The immunochromatographic detection sensor according to  claim 1 , wherein the optical waveguide is made of one material selected from the group consisting of Al 2 O 3 , Si 3 N 4 , TiO 2 , PMMA (polymethylmethacrylate), PS (polystyrene), and COC (cyclic olefin copolymer). 
     
     
         9 . The immunochromatographic detection sensor according to  claim 1 , wherein the entire or a portion of the optical waveguide, through which the probe beam passes, is overlapped with the colored conjugate bands formed on the membrane. 
     
     
         10 . The immunochromatographic detection sensor according to  claim 1 , wherein the optical waveguide is selected from the group consisting of a slab waveguide, a channel waveguide, and a rib waveguide. 
     
     
         11 . The immunochromatographic detection sensor according to  claim 10 , wherein the channel or rib optical waveguides are arranged in parallel with each other, and each of them is overlapped with each lower portion of the sample line region and control line region, so that an independent light source is used for each optical waveguide. 
     
     
         12 . The immunochromatographic detection sensor according to  claim 10 , wherein the channel or rib optical waveguides have a Y-shaped structure, therefore, the optical waveguides have one probe beam input port, and the branched optical waveguides are overlapped with each lower portion of the sample line region and control line region, so that one light source is used for the optical waveguides. 
     
     
         13 . The immunochromatographic detection sensor according to  claim 1 , wherein the optical waveguide has a thickness and width in the range of 300 nm˜1000 μm. 
     
     
         14 . The immunochromatographic detection sensor according to  claim 1 , wherein the wavelength of the probe beam is selected from the group consisting of ultraviolet, visible, and infrared rays. 
     
     
         15 . The immunochromatographic detection sensor according to  claim 1 , wherein the light source for the probe beam is selected from the group consisting of laser, LED and halogen lamp. 
     
     
         16 . The immunochromatographic detection sensor according to  claim 1 , wherein the coupling method for transmitting the probe beam through the optical waveguide is performed by using one selected from the group consisting of object lens, prism and diffraction grating. 
     
     
         17 . The immunochromatographic detection sensor according to  claim 1 , wherein the probe beam is transmitted through the optical waveguide overlapped with the lower portion of the sample line and control line regions of the membrane, and thereafter the output probe beam from the optical waveguide is measured using a detector selected from the group consisting of photodiode (PD), photo-multiplier tube (PMT), CCD (charge coupled device), and CMOS (complementary metal oxide semiconductor). 
     
     
         18 . The immunochromatographic detection sensor according to  claim 2 , wherein the amount of the colored conjugate determined by the evanescent wave of the probe beam is measured by any one selected from the group consisting of probe beam intensity at a single wavelength, white light intensity, change in probe beam wavelength, and change in probe beam phase. 
     
     
         19 . The immunochromatographic detection sensor according to  claim 2 , wherein the colored conjugate is receptor-conjugated nanoparticles, having an analyte-specific receptor on their surface. 
     
     
         20 . The immunochromatographic detection sensor according to  claim 19 , wherein the nanoparticle is made of a material selected from the group consisting of gold, silver, Fe, Co, Ni, Nd, Gd, silica and polystyrene. 
     
     
         21 . The immunochromatographic detection sensor according to  claim 19 , wherein the nanoparticle has a size in the range of 5˜200 nm. 
     
     
         22 . The immunochromatographic detection sensor according to  claim 19 , wherein the receptor is protein, DNA, peptide, amino acid, aptamer, or combinations thereof. 
     
     
         23 . An immunochromatographic detection method, comprising the steps of:
 1) applying a sample to the membrane of the immunochromatographic detection sensor according to  claim 1 ,   2) moving the sample along with the membrane,   3) transmitting the probe beam through the optical waveguide, and   4) determining the strength of the colored conjugate band by the intensity of the output probe beam, so as to analyze the component of analyte in the sample.   
     
     
         24 . The immunochromatographic detection method according to  claim 23 , wherein the interaction frequency between evanescent wave generated on the surface of optical waveguide and the colored conjugate in the band formed on the membrane is maximized, and thus the absorbance signal from the colored conjugate is greatly amplified to improve the sample detection sensitivity.