By a News Reporter-Staff News Editor at Electronics Newsweekly -- According to news reporting originating from Washington, D.C. , by VerticalNews journalists, a patent application by the inventors Hasebe, Takayuki (Tokyo , JP); Tabata, Hitoshi (Tokyo , JP); Kitamura , Shigeru (Kyoto , JP), filed on April 5, 2013 , was made available online on April 17, 2014 .
The assignee for this patent application is Arkray, Inc.
Reporters obtained the following quote from the background information supplied by the inventors: "The present invention relates to a terahertz wave measurement device and method.
"Currently, for the detection of measurement targets such as biorelated substances at practical levels, detection methods that utilize labelling such as fluorescence and color-emitting enzyme reactions are principally used. However, these detection methods, as well as causing primary antibodies to react, cause secondary antibodies, labelling substances and the like to react, and it is necessary to detect measurement targets from the emitted colors, fluorescence and the like. As a result, labor is required and detection times of several hours or more may be needed. There are also further problems, such as reactive effects due to steric exclusion of labelled molecules and the like. Moreover, there are measurement targets for which labelling is difficult or very expensive. Accordingly, a label-free detection method capable of detecting measurement targets such as biorelated substances and the like without the application of labelling is desired.
"Because terahertz waves are in an energy range corresponding to intermolecular oscillations, there are hopes for the application of terahertz waves to label-free detection.
"As a sensing device utilizing terahertz waves, a sensing device has been proposed that acquires information about a sample using electromagnetic waves that include a frequency in the frequency range from 30 GHz to 30 THz (for example, see Japanese Patent Application Laid-Open (JP-A) No.2007-78621). This sensing device is equipped with a conductor portion, a periodic structure disposed at a portion or a vicinity of the conductor portion, and a sample retention portion that retains the sample. In this sensing device, changes in the sample under conditions in which surface plasmon resonance is produced in the vicinity of the sample retention portion when electromagnetic waves interact in the conductor portion are detected. Thus, information about the sample is acquired.
"Measurement methods based on attenuated total reflection (ATR) using terahertz waves and measurement methods in which ATR is employed have also been proposed (for example, see the Pamphlet of International Publication No. 2010/044193)."
In addition to obtaining background information on this patent application, VerticalNews editors also obtained the inventors' summary information for this patent application: "However, conventional label-free detection using terahertz waves is targeted to the measurement of dry samples. If a measurement target sample is in the form of an aqueous solution, terahertz waves may not pass through the aqueous solution, because the absorption of terahertz waves in water is high.
"A technique utilizing ATR is applicable even when a measurement target sample is an aqueous solution. However, the spectrum of terahertz waves that are measured does not show a characteristic peak but is flat, or high-sensitivity measurement of the terahertz waves may not be possible.
"The present invention has been made in order to solve the problems described above, and an object of the invention is to provide a terahertz wave measurement device and method that do not require labelling of a measurement target, may measure terahertz waves with high sensitivity, and are applicable even to aqueous solutions.
"Solution to Problem
"In order to achieve the object described above, the terahertz wave measurement device of the present invention includes: a base plate at which a sample is to be disposed, the base plate being transmissive to terahertz waves; a conductive periodic structure in which a plurality of transmission portions that transmit terahertz waves are arrayed with a predetermined period, at least a surface of the conductive periodic structure being constituted with a conductive material, and the conductive periodic structure being disposed apart from a position at which the sample is disposed; and a waveguide including a total reflection surface provided at a boundary face with the conductive periodic structure, the total reflection surface totally reflecting incident terahertz waves, and the waveguide guiding incident terahertz waves in a direction toward the total reflection surface, wherein the magnitude of at least one of a distance between the position at which the sample is disposed and the conductive periodic structure, a property of the base plate, or the predetermined period is set such that terahertz waves emitted from the waveguide by total reflection at the total reflection surface show a characteristic absorption in a predetermined frequency region. The property of the base plate is, for example, a dielectric constant or refractive index.
"The conductive periodic structure may be disposed at the side of a face of the base plate that is opposite to a face thereof at which the sample is disposed.
"The base plate and the conductive periodic structure may be disposed in area contact. For example, pressure may be applied to put the base plate and the conductive periodic structure into area contact.
"At least one of the base plate and the conductive periodic structure, or the waveguide and the conductive periodic structure may be integrally structured. For example, an integral structure may be formed by vapor deposition of the conductive periodic structure at a surface of the base plate or waveguide, or by printing of a pattern of the conductive periodic structure at the same.
"The conductive periodic structure may be sandwiched between the base plate and the waveguide, pressure may be applied, and the base plate and the conductive periodic structure, and the conductive periodic structure and the waveguide may be respectively put into area contact.
"The base plate may be structured as a micro-total analysis system (micro-TAS) including a channel in which the sample is disposed. In this case, a structure may be formed in which the channel in the micro-TAS and the conductive periodic structure are spaced apart.
"The conductive periodic structure may include a wire grid structure or a metal mesh structure. The waveguide may include a prism. The base plate may include glass or plastic.
"The terahertz wave measurement method of the present invention includes: measuring a reference spectrum using the terahertz wave measurement device described hereabove, the reference spectrum including at least one of an amplitude spectrum or a phase spectrum of terahertz waves relating to a reference sample that includes a binder that specifically binds with a measurement target substance; measuring a target spectrum using the terahertz wave measurement device, the target spectrum including at least one of an amplitude spectrum or a phase spectrum of terahertz waves relating to one of a target sample in which the measurement target substance is added to the reference sample, or a target sample in which a content of the measurement target substance is unknown; and performing at least one of detection, identification or characteristic analysis of the measurement target substance on the basis of at least one of a frequency region showing a characteristic absorption or a signal strength at this frequency region in each of the reference spectrum and the target spectrum.
"Advantageous Effects of Invention
"As described above, according to the terahertz wave measurement device and method of the present invention, effects are provided in that labelling of a measurement target is made unnecessary, terahertz waves may be measured with high sensitivity, and the terahertz wave measurement device and method may be applied even to aqueous solvents.
No comments:
Post a Comment