Abstract: A surface acoustic wave (SAW) immunosensor for diagnosing allergy disease includes one or more SAW devices on each of which allergens derived from one allergy-causing substance are fixed and an allergen derived from another allergy-causing substance is not included, that is, allergens derived from different allergy-causing substances being fixed on different SAW devices; and a signal detector which detects an output signal from the SAW device. Also a method for diagnosing allergy disease is capable of measuring levels of allergen-specific IgE and total IgE in blood or another sample taken from a subject of diagnosis using a SAW immunosensor, the allergens being derived from various allergy-causing substances, thereby capable of effectively diagnosing allergy disease for various allergy-causing substances.

Abstract: Provided are a substrate used in optically detecting a target material and having an oxide layer, a method for detecting a target material using the substrate, and an optical sensor including the substrate. The substrate can provide an increased detection signal in an analysis method using the substrate.

Abstract: Provided is a method of manufacturing a microfluidic device in which coating film patterns made of a coupling agent are formed in microchannels. The method includes: forming the coating film patterns made of the coupling agent on a Si substrate; selectively oxidizing coupling agent-free regions of the Si substrate having thereon the coating film patterns made of the coupling agent using an oxidizing agent with an oxidation potential from 1 to 2 V; and adhering a PDMS (polydimethylsiloxane) microchannel structure to the selectively oxidized Si substrate to form the microchannels.

Abstract: Provided are a sensing switch and a sensing method using the same. The sensing switch includes: a substrate; a supporter on the substrate; a sensing plate that is connected to a side of the supporter and is in parallel with the substrate by a predetermined distance; a receptor binding region on an upper surface of an end portion of the sensing plate; an electric or magnetic field generation device that induces deflection of the sensing plate when a receptor bound to the receptor binding region is selectively bound to an electrically or magnetically active ligand; and a pair of switching electrodes that are separated by a predetermined distance and is connected when the sensing plate contacts the substrate due to the deflection of the sensing plate. A target material need not be labelled, a signal processing of a fluorescent or electrical detection signal using an analysis apparatus is not required, and a signal can be directly decoded by confirming whether a current flows through the switch.

Abstract: Provided is a Field-Effect Transistor (FET)-based biosensor including: a substrate; a source and a drain, disposed on the substrate, having opposite polarity to the substrate; a gate, disposed on the substrate, contacting the source and the drain; and an inorganic film capable of binding with a biomolecule, disposed on a surface of the gate. A method of manufacturing the FET-based biosensor and a method of detecting a biomolecule using the FET-based biosensor is also provided. The FET-based biosensor can be manufactured using a semiconductor fabrication process without performing an additional process. Therefore, the inorganic film can be selectively deposited on a surface of a specific gate of a single FET, or on the surfaces of some gates of a plurality of FETs using patterning. Furthermore, the FET-based biosensor can be used to effectively detect trace amounts of a target biomolecule in a sample.

Abstract: A method for identifying a biomolecule using a biomolecule detector having a field effect transistor (FET) is provided. The method comprises the steps of (a) heating a sample containing a biomolecule loaded in the detector to thereby elevate the temperature of the sample; (b) measuring electric current flowing through a channel formed between a source region and a drain region in the FET while raising the temperature in the step (a); (c) obtaining a transition temperature that is the temperature at maximum point of current variation from data measured in the step (b); and (d) identifying the biomolecule using the transition temperature obtained in the step (c).

Abstract: Provided is a method of storing a substrate having an active group or a probe molecule immobilized thereon. The method includes attaching a UV film to a surface of the substrate having the active group or probe immobilized thereon; and exposing the UV film to UV light, wherein the UV film comprises a UV-permeable base film and a pressure sensitive adhesive layer formed on a surface of the UV-permeable base film to immobilize the substrate, and when the pressure sensitive adhesive layer is exposed to the UV light, its adhesive force decreases.

Abstract: A method and a device for detecting nucleic acid are disclosed, wherein impurities in a sample can be easily removed.. The method comprises injecting a sample containing an adsorption medium with nucleic adsorbed thereon into a chamber; washing the sample; heating the sample to denature the nucleic acid; cooling down; and detecting nucleic acid by using the biomolecule detection device. The device includes: a source and a drain region; a gate electrode layer; a chamber formed over the semiconductor substrate including the gate electrode layer; and a heating means, wherein a gate adsorption layer to which a nucleic acid is adsorbed is formed on the gate electrode layer. A single-stranded nucleic acid is adsorbed to the gate adsorption layer, and a channel is formed between the source and the drain region. The current in the channel provides a basis to detect a gene.

Abstract: Provided are a sensing switch and a sensing method using the same. The sensing switch includes: a substrate; a supporter on the substrate; a sensing plate that is connected to a side of the supporter and is in parallel with the substrate by a predetermined distance; a receptor binding region on an upper surface of an end portion of the sensing plate; an electric or magnetic field generation device that induces deflection of the sensing plate when a receptor bound to the receptor binding region is selectively bound to an electrically or magnetically active ligand; and a pair of switching electrodes that are separated by a predetermined distance and is connected when the sensing plate contacts the substrate due to the deflection of the sensing plate. A target material need not be labelled, a signal processing of a fluorescent or electrical detection signal using an analysis apparatus is not required, and a signal can be directly decoded by confirming whether a current flows through the switch.

Abstract: A method of isolating nucleic acid from a sample containing nucleic acid is provided. The method includes contacting the sample with a bifunctional material that contains an amino group and a carboxyl group and is positively charged at a first pH to allow binding of the nucleic acid to the bifunctional material; and extracting the nucleic acid at a second pH higher than the first pH from the complex.

Abstract: A biomolecule detector and a method thereof are provided to detect the biomolecules in a liquid sample using a field effect transistor (FET) array. The FET array is characterized in that the transistor used has no gate electrode layer, a reference electrode is provided in the space between the transistors in the array instead of the gate electrode layer. Using the FET array, the existence of the biomolecules in the sample can be detected electrically and effectively under the circumstance where an external voltage is applied to flow the biomolecules. Using the FET array to detect the biomolecules, the deviation for each transistor is reduced and the multiplex processing is also possible to measure the plurality of analyzing samples at the same time.

Abstract: A device for detecting biomolecules includes: a semiconductor substrate; a source region and a drain region separately provided at the substrate; a chamber formed at the substrate including a region between the source region and the drain region, the chamber configured to contain a sample including the biomolecules; and an electrode which applies a voltage to the sample in the chamber. The biomolecules are mobile with respect to the electrode and sample. Methods for detecting biomolecules are also disclosed.

Abstract: A method of isolating nucleic acid from a sample containing nucleic acid is provided. The method includes contacting the sample with a bifunctional material that contains an amino group and a carboxyl group and is positively charged at a first pH to allow binding of the nucleic acid to the bifunctional material; and extracting the nucleic acid at a second pH higher than the first pH from the complex.

Abstract: Provided are a method of producing a substrate having a patterned organosilane layer and a method of using the substrate having the patterned organosilane layer. The method of producing the substrate having the patterned organosilane layer, includes: coating organosilane on a substrate to obtain an organosilane layer; coating a photoresist material on the organosilane layer; exposing the photoresist material to light through a mask to obtain a patterned surface on the photoresist material; developing an exposed or unexposed region of the photoresist material using a developer; and wet etching a portion of the organosilane layer in the region from which the photoresist material has been removed, using a HF-containing solution as an etchant.

Abstract: Provided is a method of preparing a patterned spot microarray using a photocatalyst. The method comprises coating the photocatalyst on a substrate to form a photocatalyst layer, coating a composition comprising a functional group to be connected to a biomolecule on the photocatalyst layer to form an organic layer, spotting the biomolecule on the organic layer, positioning a photomask above a spot of the biomolecule; and irradiating the spot through the photomask to pattern the spot.

Abstract: A method for simultaneously detecting a size and concentration of ionic materials includes measuring voltage drop values of at least three ionic materials of which sizes and concentrations are known using each of at least two FET-based sensors having different electrical characteristics, determining at least three points in a three-dimensional plot from the known sizes, concentrations and the measured voltage drop values, approximating the at least three points into a single plane, measuring a voltage drop value of an ionic material of which size and concentration are unknown using the at least two FET-based sensors, determining equipotential lines existing on the plane using the voltage drop value of the unknown ionic material and determining a cross point between each of the equipotential lines.

Abstract: A field effect transistor for detecting ionic material and a method of detecting ionic material using the field effect transistor. The field effect transistor for detecting ionic material includes a substrate formed of a semiconductor material, a source region and a drain region spaced apart from each other in the substrate and doped with an opposite conductivity type to that of the substrate, a channel region interposed between the source region and the drain region, an insulating layer disposed on the channel region and formed of an electrically insulating material, a first reference electrode disposed at an edge of the upper portion of the insulating layer and a second reference electrode disposed to be spaced apart from the insulating layer.

Abstract: A field effect transistor for detecting an analyte having a thiol group includes a substrate, a source region and a drain region formed apart from each other on the substrate, the source region and the drain region being doped such that a polarity of the source and drain region is opposite to a polarity of the substrate, a channel region disposed between the source region and the drain region, an insulating layer formed of an electrically insulating material and disposed on the channel region, a gold layer disposed on the insulating layer and a reference electrode disposed apart from the gold layer.

Abstract: Provided is a method of detecting the presence of a target bio-molecule or a concentration of the bio-molecule using a field effect transistor. The method includes: contacting a first sample having a first target bio-molecule with a reference electrode of a field effect transistor; measuring a first electric signal change of the field effect transistor; contacting a second sample with a sensing surface of the same field effect transistor; measuring a second electric signal change of the field effect transistor; and comparing the first electric signal with the second electric signal.

Abstract: Provided are a FET-based sensor for detecting an ionic material, an ionic material detecting device including the FET-based sensor, and a method of detecting an ionic material using the FET-based sensor. The FET-based sensor includes: a sensing chamber including a reference electrode and a plurality of sensing FETs; and a reference chamber including a reference electrode and a plurality of reference FETs. The method includes: flowing a first solution into and out of the sensing chamber and the reference chamber of the FET-based sensor; flowing a second solution expected to contain an ionic material into and out of the sensing chamber while continuously flowing the first solution into and out of the reference chamber; measuring a current in a channel region between the source and drain of each of the sensing and reference FETs; and correcting the current of the sensing FETs.