Device for measuring proteins using biosensor

Abstract

A sensor for measuring a protein with a measurement speed improved from a conventional impedance measurement, using a biosensor is provided. The sensor is capable of efficiently and accurately measuring impedance generated by a selective binding to the protein by Fourier-transforming an electric current signal which is obtained by applying a potential signal of a delta function waveform. The device for measuring a protein using a biosensor includes the biosensor including a sample inlet through which a sample is drawn in, a working electrode on which a receptor layer is coated for selective binding to the specific protein in the drawn sample, and a measuring unit including a reference electrode to form a potential difference with the working electrode, a function generator which applies a potential signal in the form of delta function to the working electrode and the reference electrode, and a data processing unit which measures impedance of the working electrode by Fourier-transforming an electric current obtained in response to the delta function waveform. Accordingly, with the device for measuring a protein using a biosensor is capable of measuring concentration of the protein with accuracy, measurement time is shortened and the concentration of protein can be accurately measured by removing the influence of dispersion.

1 . A device for measuring a protein using a biosensor, the device comprising:
 the biosensor comprising a sample inlet through which a sample is drawn in, a working electrode on which a receptor layer is coated for selective binding to the specific protein in the drawn sample, and a measuring unit including a reference electrode to form a potential difference with the working electrode;   a function generator which applies a potential signal in the form of delta function to the working electrode and the reference electrode; and   a data processing unit which measures impedance of the working electrode by Fourier-transforming an electric current obtained in response to the delta function waveform.   
     
     
         2 . The device of  claim 1 , wherein the measuring unit further comprises an auxiliary electrode to measure impedance of the working electrode, and the delta function waveform is applied between the working electrode and the auxiliary electrode. 
     
     
         3 . The device of  claim 1 , wherein the protein is a glycated hemoglobin protein formed as hemoglobin is transformed by combining with glucose. 
     
     
         4 . The device of  claim 3 , wherein the receptor layer is formed as a self-assembled monolayer (SAM) which have boronic acid derivative as end group. 
     
     
         5 . The device of  claim 1 , wherein the concentration of the specific protein is measured by measuring impedance generated on the working electrode by selective binding to the receptor layer. 
     
     
         6 . The device of  claim 1 , wherein the function generator integrates the delta function waveform and applies a step potential signal. 
     
     
         7 . The device of  claim 1 , wherein the biosensor further comprises an air outlet for the sample to move through the sample inlet to the measuring unit by capillary phenomenon. 
     
     
         8 . The device of  claim 3 , further comprising an electrochemical biosensor which is connected to the sample inlet through a micro channel, and which measures an amount of hemoglobin by the oxidation-reduction reaction of hemoglobin contained in the sample. 
     
     
         9 . The device of  claim 8 , further comprising a plunger into which capillary blood collecting tube is easily inserted and engaged to measure the glycated hemoglobin and the hemoglobin simultaneously; a body which accommodates a buffer solution containing a hemolytic substance and a oxidation-reduction pair; and a pretreatment sample feeding unit which includes an outlet in which a filter on an end of the body. 
     
     
         10 . The device of  claim 1 , wherein the working electrode is made from gold or white gold. 
     
     
         11 . The device of  claim 10 , wherein the receptor layer is formed as a self-assembled monolayer having boronic acid derivative as an end group, and the boronic acid derivative is partially transformed into a thiol group to easily combine with a gold electrode. 
     
     
         12 . The device of  claim 1 , wherein the data processing unit measures impedance which occurs when electron transfer of an oxidation-reduction pair is inhibited by a protein selectively the receptor layer on the working electrode. 
     
     
         13 . The device of  claim 12 , wherein the oxidation-reduction pair is selected from a group consisting of ferrocene, ferrocene derivatives, quinones, quinines derivatives, organic conducting salt, or viologen, hexaammineruthenium (III) chloride, dimethylferrocene (DMF), ferricinium, ferocene monocarboxylic acid (FCOOH), 7,7,8,8-tetracyanoquino-dimethane (TCNQ), tetrathia fulvalene (TTF), nickelocene (Nc), N-methyl acidinium (NMA+), tetrathiatetracene (TTT), N-methylphenazinium (NMP+), hydroquinone, 3-dimethylaminobenzoic acid (MBTHDMAB), 3-methyl-2-benzothiozolinone hydrazone, 2-methoxy-4-allylphenol, 4-aminoantipyrin (AAP), dimethylaniline, 4-aminoantipyrene, 4-methoxynaphthol, 3,3′,5,5′-tetramethyl benzidine (TMB), 2,2-azino-di-[3-ethyl-benzthiazoline sulfonate], o-dianisidine, o-toluidine, 2,4-dichlorophenol, 4-amino phenazone, and benzidine.