CN1367382A - Non-enzyme disposable detection electrode strip, its production method and application - Google Patents

Abstract

The present invention relates to a non-enzymatic disposable electrode strip for direct detection of concentrations of biomolecules, such as uric acid and hemoglobin, in a liquid sample. When the electrode strip is used for detecting the concentration of the biological molecules in the human body, the interference of signals caused by other components in blood can be avoided. The invention also provides a production method of the electrode belt and a detection device containing the electrode belt.

Description

Non-enzyme disposable detection electrode strip, its production method and application

The invention relates to a disposable electrode strip for detecting biomolecules, in particular to an electrode strip for detecting uric acid and hemoglobin.

The detection of biomolecules can be performed with two types of electrodes: enzymatic electrodes and non-enzymatic electrodes. In clinical biochemical analysis, biomolecules are detected by their reduction or enzymatic methods. Due to strict protection conditions, complex manufacturing methods and control conditions, enzyme electrodes are expensive and cannot be mass-produced. Enzyme electrodes are not disposable and not suitable for home use. In contrast, non-enzymatic electrodes can be made of disposable materials and are easy to produce, store, and use; thus, they are beneficial bioanalyzers for the detection of biomolecules such as uric acid and hemoglobin.

So far, there are no electrode strips that can effectively detect uric acid and hemoglobin. Ai-min Yu, Hai-li Zhang and Hong-yuan Chen (Analyst, 1997; 122:839-841) described the improvement of current behavior of uric acid and its trace determination on polyglycine chemically modified electrodes. The electrode can only detect uric acid samples in 0.1M phosphate buffered saline, but not whole blood samples. Such electrodes have the following defects: 1) the linear region is beyond the common diagnostic region; 2) it is not suitable for detecting blood samples; 3) the manufacturing process of the electrode is complicated and time-consuming, which is not suitable for mass production; 4) the cost is high, which is not conducive to making Disposable items.

Jyh-Myng Zen and Jen-Sen Tang (Anal.Chem.1995; 67:1892~1895) modified glassy carbon electrodes with Ru _2-x Pb _x O _7-x (lead ruthenium oxide) and detected by Osteryoung square wave galvanometer urea. The detection of the electrode in acidic uric acid solution with a pH of 1 is suitable. This electrode is not suitable for testing blood samples. In addition, this electrode also has the following defects: 1) it is expensive; 2) the detection area does not overlap with the diagnosis area; 3) the manufacturing process of the electrode is complicated and not suitable for mass production; and 4) it cannot be used to make a disposable electrode strips and are therefore not suitable for home use.

For the detection of hemoglobin, methods for cyanizing hemoglobin are well known in the art. The method refers to dissolving hemoglobin with Drabkin's solution, that is, using K ₃ Fe(CN) ₆ to oxidize Fe ²⁺ in hemoglobin to Fe ³⁺ to form partial hemoglobin (MHb). Furthermore, said MHb combines with KCN to form stable cyanated hemoglobin. The concentration of hemoglobin can be obtained by measuring its absorbance at 540nm by colorimetry. On the basis of the oxidation effect of K ₃ Fe(CN) ₆ on Fe ²⁺ in hemoglobin, hemoglobin can be detected by suitable electrodes and detectable oxidation potential. However, the above method suffers from the drawback of causing highly toxic KCN contamination.

Based on the above description, there is a need for an advanced disposable, easy-to-use and economical electrode for the detection of biomolecules, especially uric acid and hemoglobin.

One object of the present invention is to provide a non-enzyme disposable electrode belt for detecting uric acid, which is composed of an electrically insulating substrate, a conductive film layer, an electrically insulating film layer and a reactive film layer.

An object of the present invention is to provide a disposable electrode belt for detecting hemoglobin, which is composed of an electrically insulating substrate, a conductive film layer, an electrically insulating film layer and a reactive film layer.

Another object of the present invention is to provide a method for producing a disposable non-enzymatic electrode strip for detecting uric acid and hemoglobin.

Another object of the present invention is to provide a device for detecting uric acid and hemoglobin.

Another object of the present invention is to provide a method for detecting the concentration of uric acid in a liquid sample, and a method for detecting the concentration of hemoglobin in a liquid sample.

Figure 1a. Top view of an electrode strip according to the invention.

Figure 1b. Front view of an electrode strip according to the invention.

Figure 2a. Schematic diagram of the steps of coating a conductive film layer 2 on an electrically insulating substrate 1, the coating comprising at least one anode and one cathode.

Figure 2a illustrates the steps of coating a conductive film layer 2 on an electrically insulating substrate to form at least one anode and one cathode.

Fig. 2b. Schematic diagram of the step of partially covering the electrically insulating film layer on the conductive film layer. The uncovered conductive film layer includes an anode connection point 6 , a cathode connection point 7 , a working electrode 8 and a reference electrode 9 .

Fig. 2c. Schematic diagram of the steps of applying the reaction film layer 4 to the reaction area so that the working electrode and the reaction electrode are covered.

Figure 2d. Schematic diagram of the steps of coating the protective film layer on the reaction film layer.

Fig. 3a. Schematic diagram of hemolysis on the reaction film layer of the electrode belt for detecting hemoglobin.

Figure 3b. Schematic diagram of measuring the concentration of uric acid and hemoglobin by adjusting the current of the detection device.

Fig. 4. Schematic diagram of detecting the concentration of uric acid in blood respectively by the method of combining the electrode strip and uricase according to the present invention with the EPAC bioanalyzer.

Fig. 5 is a schematic diagram of detecting the concentration of hemoglobin in blood respectively by using the electrode strip and the cyanide hemoglobin method of the present invention.

Fig. 6. The hematocrit in the whole blood is detected respectively by the electrode strip and the centrifugation method according to the present invention.

The present invention is characterized in that the disposable detection electrode belt is modified with a water-soluble medium containing redox electrons and a surfactant. The electrode strip detects the concentration of biomolecules in a liquid sample by capturing the oxidation current containing redox electron mediators and the signals generated by biomolecules such as uric acid and hemoglobin.

Surprisingly, we found that the electrode strips modified with a low concentration of cationic surfactants improved the reaction rate and accuracy of uric acid detection. On the other hand, the electrode strip modified with a high concentration of neutral surfactant improves the speed and accuracy of the hemoglobin detection reaction. Electrode strip

An object of the present invention is to provide a non-enzymatic, disposable electrode strip for detecting uric acid, which consists of the following parts:

1) an electrical insulating substrate;

2) a conductive film layer, which is coated on one side of the insulating material to form independent, disconnected anodes and cathodes;

3) An electrically insulating film layer coated on a part of the conductive film layer, wherein at least one reference electrode is formed at one end of the anode not coated with a conductive layer and an anode connector is formed at the other end, and at the cathode not coated with a conductive layer one end forming at least one working electrode and the other end forming a cathode connector;

4) a reaction membrane layer, which includes a carrier, a conductive medium and a cationic surfactant with a concentration lower than 0.05%, and the coated area includes at least the working electrode and the reference electrode, so as to separate Connect the working electrode and the reference electrode, wherein the reaction membrane layer does not include any enzyme.

Another object of the present invention is to provide a non-enzymatic, disposable electrode strip for detecting hemoglobin, which consists of the following parts:

1) an electrical insulating substrate;

2) A conductive film layer is applied to one side of the insulating material to form independent, disconnected anodes and cathodes;

3) Apply an electrically insulating coating to a portion of the conductive film layer, including at least one reference electrode and the other end of the anode connector at the uncoated anode end, and at least at the uncoated cathode end the end of one working electrode and the other cathode connector;

4) The reaction film layer is composed of a carrier, a conductive medium and a neutral surfactant with a concentration higher than 1%, and the coated area includes at least the working electrode and the reference electrode, that is to say, the working electrode and the reference electrode. Than the electrode connection is completely separate, the reaction membrane layer described here does not include how the enzyme.

In the present invention, the electrically insulating substrate has a flat surface and has insulating properties. The material has a resistance to heat above 40°C, preferably 40-80°C, and its conductivity can be increased by heat treatment. Any material having the above properties is suitable as an electrically insulating substrate according to the present invention. Preferably, these materials may be selected from the following substances: polyvinyl chloride (PVC), fiber optic glass (FR-4), polyester suphone, insulating bakelite board, polyethylene terephthalate (PET) board, polycarbonate Ester (PC) boards, glass boards and ceramic boards (CEM-1).

According to the present invention, a conductive film layer is applied to one side of the insulating substance to form separate disconnected anodes and cathodes. Screen coating with printing inks or adhesive metal stencils is preferred. More preferably, the metal film layer is selected from the following metals: gold, silver, platinum and padium. The printing ink is selected from carbon ink, gold ink, silver ink, or a mixture of carbon and silver black water, unstable graphite, copper ink, or a mixture of the above-mentioned various inks (for example, firstly use printing silver ink, and then use print carbon ink). The cathode is partially covered by an electrically insulating film layer, the uncovered ends of which form a reference electrode and a cathode connector, respectively. The anode is partially covered by an electrically insulating film layer, and its uncovered ends form a reference electrode and an anode connector, respectively. The reference electrode of the cathode is covered by the reaction film layer and cooperates with the working electrode of the anode to detect the influence of the electric induction. Anode and cathode connectors are often connected to current sensors.

According to the present invention, the electrical insulating film layer is coated on one surface of the electrical insulating substrate, but does not cover the above-mentioned cathode connector, anode connector, working electrode and reference electrode. The area not covered by the electrical insulation film layer includes the working electrode and the reference electrode to form a reaction area, and then the reaction film layer is coated on this area for detecting samples. Preferably the thickness of the electrically insulating film layer is greater than 0.6 mm.

According to the present invention, the reaction film layer is applied to the reaction area by any suitable method, preferably by pipetting or screen printing. The reaction film layer is composed of water-soluble redox dielectric, carrier and surfactant. The reaction film layer is in contact with the sample to generate an electrochemical reaction. Also, the reactive film layer may be covered by a protective film layer.

According to the present invention, the conducting medium comprises an electrolyte having a redox capacity lower than that of the sample to be tested. The conductive medium changes from an oxidized state to a reduced state after reacting with the sample. The conductive medium can be reduced to an oxidized state after a certain forced voltage is applied. Changes in potential, resistance, and current resulting from electrochemical reactions can be transported through the conductive membrane layer, ie from the working electrode and counter reference electrode connected to the reaction membrane layer to the anode and cathode connectors. The preferred conducting medium is potassium ferricyanide. Its dosage accounts for 0.3%-5% of the weight ratio of the reaction film layer.

As described in the present invention, since the sample is hydrophilic, it is difficult to get close to the hydrophobic conductive film layer, so a carrier for absorbing the sample is required. Carriers increase the amount of sample uptake, thereby enhancing the signal that is transferred to the conductive membrane layer. The reaction film layer is in contact with the sample and undergoes an electrochemical reaction with it. Therefore, the carrier can be spread over the entire reaction membrane area so that the signal can be completely transferred. Preferably, the carrier is selected from microcrystalline cellulose, carboxymethylcellulose or methylcellulose. More preferred is cellulose with a size of less than 100 um. The weight ratio of cellulose to the reaction film layer is about 0.01%-0.1%.

As described herein, the carrier may optionally comprise a polymer. The polymer facilitates a certain tackiness of the reactive film layer. Thus, the reaction film layer can be completely distributed. The polymer is selected from the group consisting of: polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyoxyethylene (PEG), gel and mixtures thereof. More preferably the polymer comprises 0-15% by weight of the reacted film layer.

According to the present invention, in the detection of uric acid, the surfactant used in the reaction film layer is an anionic surfactant, and its concentration is less than 0.05% by weight. Anionic surfactants known in the art are suitable for the present invention. Preferably, the anionic surfactants include ammonium-containing surfactants. More preferably, the surfactant is selected from N-acetyl-N,N,N-trimethyl-ammonium bromide and alkyldimethylammonium halides. The preferred dosage of its anionic surfactant is 0.01%-0.03%.

On the other hand, according to the present invention, in the detection of hemoglobin, the surfactant used in the reaction film layer is a neutral surfactant, and its concentration is greater than 1% by weight. Any suitable neutral surface activity known in the art can be used in the reaction film layer of the hemoglobin detection electrode of the present invention. Preferably, the neutral surfactant includes: polyethylene oxide, ethylene oxide, aliphatic alcohol, tertiary amine oxide and hydrogen triphosphate oxide. More preferably, the surfactant is selected from trinitrotoluene and polyoxyethylene alkyl ether. Most preferably, the concentration range of the neutral surfactant is 1%-5%.

As described in the present invention, the non-enzyme disposable electrode strip for detecting hemoglobin can be used for detecting the concentration of hemoglobin. The ratio of hematocrit/hemoglobin known to those skilled in the art is 2.9-3.1. Therefore, the blood cell density can be calculated by measuring the concentration of hemoglobin using the electrode strip for detecting hemoglobin of the present invention.

Preparation of electrode strips

Another object of the present invention is to provide a method for producing disposable, non-enzymatic electrode strips for detecting uric acid (or hemoglobin), consisting of the following steps:

a) applying a conductive film layer to one side of the insulating substance to form separate, disconnected anodes and cathodes;

b) Applying an electrically insulating coating to a portion of the conductive film layer, wherein one end of the conductive layer uncovered by the anode is at least one reference electrode and the other end is an anode connector. One cathode end uncovered by the conductive layer is at least one working electrode and the other end is a cathode connector.

c) Screening or dripping a reaction film layer on the area including at least the working electrode and the reference electrode, so as to separately connect the working electrode and the reference electrode.

According to the present invention, firstly, a conductive film layer is coated on one side of a flat insulating material to form at least one anode and a cathode that are separated from each other. After coating, the conductive film layer is dried at 35°C-80°C.

According to the present invention, then, part of the electrically insulating film layer with a thickness equal to or greater than 0.6 mm is printed on the conductive film layer. The uncovered portion of the conductive film layer forms an anode connector, a cathode connector, a working electrode, and a reference electrode. The area enclosed by the ring-shaped working electrode and the reference electrode or any other suitable shape is the area of the reaction film layer.

According to the present invention, in the third step, the reaction film layer is screened or dropped onto the reaction area, so that a single working electrode and a reference electrode can be connected. The area may be circular or any other suitable shape. A variety of common screening techniques can be used in the present invention. Moreover, a new screen printing technique has been disclosed in R.O.C. Patent Application No. 85,109,554 by one of the inventors of the present invention, which can also be used in the preparation method described in the present invention.

According to the present invention, the fourth step is to further dry the reaction film layer at 40°C-80°C. A protective film layer may optionally be on top of or coated on the reactive film layer. Such a disposable non-enzymatic uric acid detection electrode strip was produced.

Detection device

Another object of the present invention is to provide a device for detecting uric acid, which includes a disposable non-enzymatic uric acid detecting electrode belt and an amperometric sensor for directly analyzing uric acid in a liquid sample.

Wherein said electrode belt comprises:

1) an electrically insulating substrate;

2) a conductive film layer, which is coated on one side of the above-mentioned insulating material to form independent, disconnected anodes and cathodes;

3) An electrically insulating coating applied to a portion of the conductive film layer, including at least one reference electrode at the end of the uncoated anode and the end of another anode connector, and at the end of the uncoated anode The cathode terminal includes at least one working electrode and another terminal of the cathode connector;

4) a reaction membrane layer, which comprises a carrier, a conductive medium and a cationic surfactant with a concentration lower than 0.05%, and the coated area includes at least the working electrode and the reference electrode, That is to say, the connection of the working electrode and the reference electrode is completely separated, and the reaction membrane layer described here does not include any enzyme. The current sensor is connected to the cathode connector and the anode connector of the electrode belt for detecting uric acid, and includes a voltage output device, a signal receiver and a display device, wherein the voltage output device can provide the reaction film layer of the uric acid detection electrode strip A voltage lower than 400mv, so that when the reaction film layer on the uric acid detection electrode belt reacts with the uric acid sample, the conductive medium is oxidized from a reduced state to an oxidized state; the signal receiver receives the current generated during the oxidation-reduction reaction , voltage or resistance changes, and transmit this to the display device to display the concentration of uric acid in the sample.

Another object of the present invention is to provide a device for detecting hemoglobin, the device: a disposable non-enzymatic electrode strip for detecting uric acid and an amperometric sensor for directly analyzing hemoglobin in a liquid sample.

The electrode strips include

1) an electrical insulating substrate;

2) A conductive film layer is applied to one side of the insulating material to form independent, disconnected anodes and cathodes;

3) Apply an electrically insulating coating to a portion of the conductive film layer, including at least one reference electrode and the other end of the anode connector at the uncoated anode end, and at least at the uncoated cathode end the end of one working electrode and the other cathode connector;

4) The reaction film layer is composed of a carrier, a conductive medium and a neutral surfactant with a concentration greater than 0.05%, and the coated area includes at least the working electrode and the reference electrode, that is to say, the working electrode and the reference electrode The connection of the electrodes is completely separated, and the reaction membrane layer described here does not include any enzymes. The current sensor is connected to the cathode connector and the anode connector of the electrode belt for detecting hemoglobin, and is composed of a voltage output device, a signal receiver and a display device, wherein the voltage output device provides a voltage lower than 400mv. The reaction film layer on the electrode belt for detecting hemoglobin reacts with the uric acid sample to oxidize the conductive medium from the reduced state to the oxidized state, and the signal receiver receives the change of current, voltage or resistance generated during the oxidation-reduction reaction, and transmits this The concentration of hemoglobin in the sample is displayed on the display device.

According to the present invention, the detection condition is that the working voltage is lower than 400mv and the pH value is between 5.0-10.0, which can avoid the interference of other oxidative components. Detection method

Another object of the present invention is to provide a method for detecting uric acid concentration in a liquid, the method comprising: dropping the liquid on the non-enzyme disposable uric acid detection electrode belt of the present invention, and controlling the current sensor below 400mv Operate at a low operating voltage and within the pH range of 7.0-10.0.

Another object of the present invention is to provide a method for detecting hemoglobin concentration in a liquid, the method comprising: dropping the liquid on the non-enzyme disposable uric acid detection electrode belt of the present invention, and operating at a low temperature below 400mv Voltage and pH are controlled within a range of 5.0-8.0 by an amperometric sensor.

According to the invention, the detection method of the non-enzyme electrode strip can be conveniently implemented by using the electrochemical detection device. Drop a drop of complete whole blood sample on the reaction area of the non-enzyme disposable electrode belt for detecting uric acid or hemoglobin of the present invention, and the uric acid detection device or hemoglobin detection device can detect the redox reaction current of uric acid or hemoglobin respectively. This electrochemical reaction technology is commonly used in electrochemical blood glucose monitors that detect blood sugar. The present invention uses the redox electronic medium to transmit the redox reaction information of uric acid and controls the reaction conditions at a pH value of 7.0-10.0 and a low operating voltage below 400mv to avoid the interference of glucose and ascorbic acid vitamin C in the blood. The method of direct detection of uric acid in whole blood is new and disclosed in the present invention for the first time. Similarly, the method of directly detecting hemoglobin in whole blood is also brand new, and it is disclosed for the first time in the present invention. This method uses redox electron mediator to transmit the redox reaction information of hemoglobin and controls the pH value of the reaction between 5.0-8.0, below 400mv The low operating voltage to avoid the interference of glucose and ascorbic acid vitamin C in the blood.

application

The invention can be used to detect biomolecules such as uric acid or hemoglobin in any liquid sample. When the whole blood sample is used as a sample to detect uric acid or hemoglobin, other components in the blood, especially ascorbic acid vitamin C, will interfere. The detection device and the disposable detection electrode belt of the present invention can directly detect uric acid or hemoglobin in conventional whole blood samples, and are suitable for home use.

An important advantage of the present invention is that it excludes the use of biologically active substances such as enzymes. Therefore, the invention simplifies the production process, reduces the production cost, prolongs the storage time, and relaxes the storage condition requirement of the detection electrode belt.

Figures 1a and 1b are top and front views, respectively, of the electrode strip of the present invention. The electrode strip is composed of an electric insulating substrate 1, a conductive film layer 2 coated on the electric insulating substrate, an electric insulating film layer 3 coated on the conductive film layer 2 and a reaction film layer 4 reacting with the sample.

The electrically insulating substrate 1 of the present invention is connected to a conductive film layer 2 . The cathode of the conductive film layer 2 is partially covered by the electrical insulating film layer 3 , and the two uncovered terminals of the cathode are the working electrode 8 and the cathode connector 6 respectively. The reaction film layer 4 covers the cathode working electrode 8, and the working electrode 8 is used to detect the induced electrical effect of the sample during the electrochemical reaction of uric acid. The cathode connector 6 is used to connect with the current sensor. The anode is also partially covered by the electrical insulating film layer, and the two uncovered terminals of the anode are the reference electrode 9 and the anode connector 7 respectively. The reference electrode 9 of the anode is covered by the reaction film layer 4, and cooperates with the working electrode of the cathode to detect the induced electric effect.

The preparation of electrode strips is shown in Figures 2a, 2b, 2c and 2d. As shown in FIG. 2 , first, the conductive film layer 2 is coated on one surface of the planar material 1 by screen printing or the like to form at least one anode and one cathode, which are independently spaced from each other.

As shown in FIG. 2 b , the uncovered part of the conductive film layer forms the cathode connector 6 , the anode connector 7 , the working electrode 8 and the reference electrode 9 . The annular working electrode 8 and the reference electrode 9 enclose an area.

As shown in Figures 2c and 2d, the conductive medium is screened on the circular area of the reaction membrane layer 4, and a protective film layer is optionally coated on or around the circular area of the reaction membrane layer.

The examples given below are intended to illustrate but not limit the invention.

Example 1 Detection of biochemical substances The detection of uric acid and hemoglobin is controlled at a pH of 7.0-10.0 and a working voltage lower than 400mv to avoid interference from glucose and ascorbic acid in blood.

The present invention finds that normal concentration of vitamin C will not affect the detection of uric acid and hemoglobin. Therefore, biochemical substances can be accurately detected. Figure 3a shows the hemolytic reaction induced on the reactive film layer of the hemoglobin detection electrode. Figure 3b shows that reducing the interference of uric acid by adjusting the current can amplify the signal of the hemoglobin response.

Example 2 The detection of uric acid

On a plane of polyvinyl chloride (PVC) substrate, carbon ink is screen-printed to form a conductive film layer 2, which includes a set of independent disconnected anodes and cathodes, and then dried at 40°C-80°C. Then a portion of the electrically insulating film layer 3 with a thickness of 0.6 mm is screen-printed on the conductive film layer 2 . The uncovered part of the conductive mold layer forms the cathode connector 6 , the anode connector 7 , the working electrode 8 and the reference electrode 9 . The circular area formed by the working electrode 8 and the reference electrode 9 is the range of the reaction membrane layer 4 .

Drop the slurry substance made up of the following components and ratios on the circled area of the reaction film layer 4 with a straw.

Methylcellulose 0.01%

CTAB (N-acetyl-N, N, N-trimethyl-ammonium bromide) 0.01%

_H2O 99.68%

Potassium ferricyanide 0.3%

After the above substances are dropped on the reaction film layer 4, they are dried at 35°C-80°C. The protective film layer 5 is coated on and around the reactive film layer 4 . Through the above steps, the disposable non-enzymatic uric acid detection electrode belt is successfully prepared.

Using the disposable non-enzymatic uric acid detection electrode belt of the present invention obtained by the above method, it takes 20 seconds to detect uric acid in the whole blood sample. The test results are the same as those of any conventional method for detecting uric acid. Fig. 4 is the comparison result of uric acid concentration in the slurry after combining uricase with EPAC biochemical analyzer.

The results show that the disposable non-enzymatic uric acid detection electrode belt of the present invention can accurately detect the concentration of uric acid in blood, and the whole blood sample is used without any pretreatment.

Example 3 Detection of uric acid

Repeat the steps of Example 2 to drop the slurry substance made up of the following components and ratios on the circled area of the reaction film layer 4 with a straw.

Methylcellulose 0.05%

PEG Polyethylene Glycol 15.00%

CTAB (N-acetyl-N, N, N-trimethyl-ammonium bromide) 0.03%

_H2O 83.092%

Potassium ferricyanide 1.00%

Using the disposable non-enzymatic uric acid detection electrode belt of the present invention obtained by the above method, it takes 30 seconds to detect uric acid in the whole blood sample. The test results are the same as those obtained by using the EPAC biochemical analyzer to detect uric acid. The results show that the disposable non-enzymatic uric acid detection electrode belt of the present invention can accurately detect the concentration of uric acid in blood, and the whole blood sample is used without any pretreatment.

Example 4 The detection of hemoglobin and hemolysis

The steps of repeating example 2 are dripped on the circle area of the reaction film layer 4 with a straw by the following components and ratios:

Methylcellulose 0.05%

Triton 100 (Triton 10) 4.00%

_H2O 92.98%

Potassium ferricyanide 3.00%

Using the disposable non-enzymatic hemoglobin detection electrode belt of the present invention obtained by the above method, it takes 30 seconds to detect the hemoglobin in the whole blood sample. As shown in Figure 5, the test results are the same as those obtained by using the cyanide-hemoglobin method to detect hemoglobin. Moreover, the blood cell density detection and centrifugation detection results of the electrode belt according to the present invention are the same (as shown in FIG. 6 ).

The result shows that the disposable non-enzyme hemoglobin detection electrode belt of the invention can accurately detect the hemoglobin and blood cell density in the blood, and the whole blood sample is used without any pretreatment.

Example 5 The detection of hemoglobin and hemolysis

The step of repeating example 3, difference is to make following change to the composition and the ratio of slurry substance:

Ultra-micro optical fiber (average diameter about 20um) 0.05%

PVC (polyvinyl alcohol) 10.00%

Gel 3.50%

_H2O 81.40%

Potassium ferricyanide 5.00%

It takes 80 seconds to detect the hemoglobin in the whole blood sample using the disposable non-enzymatic hemoglobin detection electrode belt of the present invention obtained by the above method. As shown in Figure 5, the test results are the same as those obtained by using the cyanide-hemoglobin method to detect hemoglobin. The result shows that the disposable non-enzyme hemoglobin detection electrode belt of the invention can accurately detect the hemoglobin and blood cell density in the blood, and the whole blood sample is used without any pretreatment.

The above examples clearly show that the electrode strip for detecting hemoglobin of the present invention does not require any biologically active substances, and the production process is simple and fast. Moreover, the present invention can accurately detect the hemoglobin concentration of the whole blood sample under the conditions of a low operating voltage lower than 400mv and a pH value of 5.0-8.0.

Comparative Example 6 Detection of Uric Acid

The electrode strip described in the present invention and the electrode strip described in the applicant's patent application USSN09/295,400 filed on April 21, 1999 were used to detect uric acid respectively. The test results of five samples with different concentrations are shown in the table below: whole blood sample 1 2 3 4 5 6 standard uricase method Mean (mg/dl) 3.55 5.11 7.35 9.10 10.20 11.85 Electrode belt of the present invention Mean (mg/dl) 3.60 5.20 7.10 8.90 10.40 11.90 %CV 3.80 4.50 3.40 3.40 5.40 2.00 Electrode straps in USSN 09/295,400 Mean (mg/dl) 3.50 5.60 6.80 8.90 10.50 12.00 %CV 12.00 8.50 7.30 6.00 4.00 4.60

As shown in the above table, the electrode strips of the present invention and USSN 09/295,400 have high accuracy. However, the electrode strips of the present invention are superior to the electrode strips of USSN 09/295,400 in terms of the CV% shown. Moreover, the detection time of the electrode strip shown in the present invention is only 1/10 of that of the electrode strip in USSN 09/295,400.

Claims (39)

1. A non-enzyme, disposable uric acid detection electrode belt, the electrode belt comprising: 1) an electrical insulating substrate; 2) a conductive film layer, which is coated on one side of the insulating material to form independent, disconnected anodes and cathodes; 3) an electrically insulating coating applied to a portion of said conductive film layer, wherein one end of said conductive layer not covering the anode forms at least one reference electrode and the other end forms an anode connector, forming at one end of the conductive layer uncovered cathodes at least one reference electrode and the other end forming a cathode connector; 4) a reaction film layer, which is composed of a carrier, a conductive medium and an anionic surfactant with a concentration lower than 0.05%, and its coated area includes at least the working electrode and the reference electrode, so that the The working electrode and the reference electrode are connected separately, and the reaction membrane layer does not include any enzyme. 2. The electrode strip for detecting uric acid according to claim 1, wherein the electrically insulating substrate has a flat surface and insulating properties. 3. The electrode strip for detecting uric acid according to claim 1, wherein the heat resistance of the electrically insulating substrate is higher than 40°C, preferably 40°C-80°C. 4. The electrode belt for detecting uric acid as claimed in claim 1, wherein said electrically insulating substrate is made of the following materials: polyvinyl chloride (PVC), optical fiber glass (FR-4), polyester suphone, insulating bakelite , Polyethylene terephthalate (PET) board, polycarbonate (PC) board, glass board or ceramic board (CEM-1). 5. The electrode belt for detecting uric acid according to claim 1, wherein the reaction film layer is in contact with the sample and undergoes an electrochemical reaction. 6. The electrode belt for detecting uric acid according to claim 1, wherein the reaction film layer is applied to the reaction area by means of pipetting or screen printing. 7. The electrode belt for detecting uric acid according to claim 1, wherein the reaction film layer is further covered with a protective film layer. 8. the electrode belt that detects uric acid as claimed in claim 1, wherein said anionic surfactant is N-acetyl-N, N, N-trimethyl-ammonium bromide. 9. The electrode belt for detecting uric acid according to claim 1, wherein the weight ratio of the concentration of the anionic surfactant is 0.01%-0.03%. 10. The electrode strip for detecting uric acid according to claim 1, wherein the carrier is selected from microcrystalline cellulose, carboxymethyl cellulose, methyl cellulose and mixtures thereof. 11. The electrode belt for detecting uric acid as claimed in claim 1, wherein said carrier optionally includes a polymer selected from the group consisting of: polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyethylene glycol (PEG ), gelatin and mixtures thereof. 12. The electrode belt for detecting uric acid according to claim 1, wherein the carrier is microcrystalline cellulose with a size as small as 100 μm 13. The electrode belt for detecting uric acid according to claim 1, wherein the cellulose carrier is used in an amount of about 0.01% to about 0.1% by weight of the reaction film layer. 14. The electrode belt for detecting uric acid according to claim 11, wherein the polymer is used in an amount of about 0%-15% by weight of the reaction film layer. 15. The electrode belt for detecting uric acid according to claim 1, wherein the conducting medium is K ₃ Fe(CN) ₆ . 16. The electrode belt for detecting uric acid according to claim 1, wherein the amount of the conductive medium accounts for 0.3%-5% of the weight ratio of the reaction film layer. 17. A non-enzymatic, disposable electrode strip for detecting hemoglobin, which consists of the following parts: 1) an electrical insulating substrate; 2) A conductive film layer is applied to one side of the insulating material to form independent, disconnected anodes and cathodes; 3) An electrically insulating coating applied to a portion of the conductive film layer, including at least one reference electrode and another anode connector end at the uncoated anode end, and at least one the end of the reference electrode and the other cathode connector; 4) The reaction membrane layer is composed of a carrier, a conductive medium and an anionic surfactant with a concentration lower than 0.05%, and the coated area includes at least the working electrode and the reference electrode, that is to say the working electrode and the reference electrode. The connections to the electrodes are completely separate, and the reaction membrane layer described here does not include any enzymes. 18. The electrode strip for detecting hemoglobin according to claim 17, wherein the electrically insulating substrate has a flat surface and insulating properties. 19. The electrode strip for detecting hemoglobin according to claim 17, wherein the heat resistance of the electrically insulating substrate is higher than 40°C, preferably 40°C-80°C. 20. the electrode belt that detects uric acid described in claim 17, wherein said electrical insulation substrate is made of polyvinyl chloride (PVC), optical fiber glass (FR-4), polyester suphone, insulating bakelite board, polyethylene terephthalic acid Composed of glycol ester (PET) board, polycarbonate (PC) board, glass board and ceramic board (CEM-1). 21. The electrode belt for detecting hemoglobin according to claim 17, wherein the reaction film layer is in contact with the sample and undergoes an electrochemical reaction. 22. The electrode belt for detecting hemoglobin according to claim 17, wherein the reaction film layer is applied to the reaction area by means of pipetting or screen printing. 23. The electrode belt for detecting hemoglobin as claimed in claim 17, wherein said neutral surfactant is Triton. 24. The electrode belt for detecting hemoglobin according to claim 17, wherein the weight ratio of the cationic surfactant is 1%-5%. 25. The electrode strip for detecting hemoglobin as claimed in claim 17, wherein said carrier is a mixture of microcrystalline cellulose, carboxymethyl cellulose and methyl cellulose. 26. The electrode belt for detecting hemoglobin according to claim 17, wherein the carrier optionally includes a polymer selected from the group consisting of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyoxyethylene (PEG), Gelatin and mixtures thereof. 27. The electrode belt for detecting hemoglobin according to claim 17, wherein the carrier is microcrystalline cellulose with a size of less than 100 um. 28. The electrode belt for detecting hemoglobin as claimed in claim 17, wherein the cellulose carrier is used in an amount of about 0.01%-0.1% by weight of the reaction membrane layer. 29. The electrode belt for detecting hemoglobin as claimed in claim 17, wherein the polymer is used in an amount of about 0%-15% by weight of the reaction film layer. 30. The electrode belt for detecting hemoglobin according to claim 17, wherein the conductive medium is _K3Fe (CN) ₆ . 31. The electrode belt for detecting hemoglobin according to claim 17, wherein the amount of the conducting medium accounts for 0.3%-5% of the weight ratio of the reaction film layer. 32. The electrode belt for detecting hemoglobin according to claim 17, which is often used in the detection of blood cell density. 33. A method of producing an electrode strip as claimed in claim 1 or 17, consisting of the steps of: a) applying a conductive film layer to one side of the insulating substance to form separate, disconnected anodes and cathodes; b) applying an electrically insulating coating to a portion of the conductive film layer, wherein one end of the conductive layer uncovered by the anode forms at least one reference electrode and the other end forms an anode connector, and the uncovered end forms the cathode one end of which forms at least one working electrode and the other end forms a cathode connector; c) Screen printing or dropwise adding the reaction film layer to at least the area including the working electrode and the reference electrode, so that the working electrode and the reference electrode are connected separately. 34. A device for detecting uric acid, which is composed of the following parts: a disposable non-enzymatic electrode belt for detecting uric acid and a current sensor for analyzing uric acid in liquid samples; The electrode belt consists of the following parts 1) an electrical insulating substrate; 2) a conductive film layer, which is coated on one side of the insulating material to form independent, disconnected anodes and cathodes; 3) An electrically insulating coating applied to a portion of the conductive film layer, including at least one reference electrode and the end of another anode connector at the end of the uncoated anode, and at the end of the uncoated cathode ends including at least one working electrode and another end of the cathode connector; 4) Reactive membrane layer, which is composed of a carrier, a conductive medium and a cationic surfactant with a concentration lower than 0.05%, and the coated area includes at least the working electrode and the reference electrode, that is to say The connection of the working electrode and the reference electrode is completely separated, and the reaction membrane layer described here does not include any enzyme. The current sensor is connected to the cathode connector and the anode connector of the electrode strip for detecting uric acid, and it is composed of a voltage output device, a signal receiver and a display device, wherein the voltage output device can provide the reaction film layer of the uric acid detection electrode strip Provides a voltage below 400mv to oxidize the conductive medium from a reduced state to an oxidized state after reacting with a uric acid sample; the signal receiver receives changes in current, voltage or resistance generated during the redox reaction and transmits this The concentration of uric acid in the sample is displayed on the display device. A device for detecting hemoglobin is composed of the following parts: a disposable non-enzymatic electrode belt for detecting uric acid and a current sensor for analyzing hemoglobin in liquid samples. The electrode belt consists of the following parts 1) an electrical insulating substrate; 2) A conductive film layer is applied to one side of the insulating material to form independent, disconnected anodes and cathodes; 3) Apply an electrically insulating coating to a portion of the conductive film layer, including at least one reference electrode and the other end of the anode connector at the uncoated anode end, and at least at the uncoated cathode end the end of one working electrode and the other cathode connector; 4) The reaction film layer is composed of a carrier, a conductive medium and a neutral surfactant with a concentration greater than 0.05%, and the coated area includes at least the working electrode and the reference electrode, that is to say, the working electrode and the reference electrode The connection of the electrodes is completely separated, and the reaction membrane layer described here does not include any enzymes. The current sensor is connected to the cathode connector and the anode connector of the electrode belt for detecting hemoglobin, and is composed of a voltage output device, a signal receiver and a display device, wherein the voltage output device provides a voltage lower than 400mv. The reaction film layer on the electrode belt for detecting hemoglobin reacts with the uric acid sample to oxidize the conductive medium from the reduced state to the oxidized state, and the signal receiver receives the change of current, voltage or resistance generated during the oxidation-reduction reaction, and transmits this The concentration of hemoglobin in the sample is displayed on the display device. 35. A device for detecting hemoglobin is composed of the following parts: a disposable non-enzymatic electrode belt for detecting hemoglobin and a current sensor for analyzing hemoglobin in liquid samples; The electrode belt consists of the following parts 1) an electrical insulating substrate; 2) A conductive film layer is applied to one side of the insulating material to form independent, disconnected anodes and cathodes; 3) Apply an electrically insulating coating to a portion of the conductive film layer, including at least one reference electrode and the other end of the anode connector at the uncoated anode end, and at least at the uncoated cathode end the end of one working electrode and the other cathode connector; 4) The reaction film layer is composed of a carrier, a conductive medium and a cationic surfactant with a concentration lower than 0.05%, and the coated area includes at least the working electrode and the reference electrode, that is to say, the working electrode and the reference electrode. The connections to the electrodes are completely separate, and the reaction membrane layer described here does not include any enzymes. The current sensor is connected to the cathode connector and the anode connector of the electrode band for detecting hemoglobin, and it is composed of a voltage output device, a signal receiver and a display device, wherein the voltage output device can provide a voltage lower than 400mv, which is used to detect uric acid The reaction film layer on the electrode belt reacts with the hemoglobin sample to oxidize the conductive medium from the reduced state to the oxidized state, and the signal receiver receives the change of current, voltage or resistance generated during the oxidation-reduction reaction, and transmits this to the display device shows the concentration of hemoglobin in the sample. 36. A device as claimed in claim 39 or 40, wherein the detection electrode strip is disposable. 37. The device of claim 39 or 40, wherein the test sample is blood. 38. A method for detecting uric acid concentration in a liquid, comprising the steps of: dripping a liquid sample on the electrode strip as claimed in claim 1, and controlling the current sensor at a low operating voltage lower than 400mv, pH value Operate under the conditions of 7.0-10.0. 39. A method for detecting hemoglobin concentration in a liquid, comprising the steps of: dripping a liquid sample on the electrode strip as claimed in claim 17, and controlling the current sensor at a low operating voltage lower than 400mv, pH value Operate under the conditions of 5.0-8.0.

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