TW201805623A - Method for manufacturing test strip and method for detecting the concentration of phosphoric acid applying the redox potential to retrieve a current signal of the test strip to confirm the concentration in a mixed solution - Google Patents

Abstract

A method for manufacturing a test strip and a method for detecting the concentration of phosphoric acid are as follows. First, a copper electrode is formed on a first region of a substrate, a first nickel layer is formed on the copper electrode, and then using a method of electroless nickel immersion gold to form a first gold layer on the first nickel layer, finally an insulating layer is formed on a second region of the substrate, and the test strip is finally formed. Furthermore, the redox potential of phosphoric acid is obtained and the reference and comparison data of the concentration of phosphoric acid is established, a mixed solution blended with phosphoric acid is titrated to the test strip, and applying the redox potential to retrieve a current signal, followed by comparing the current signal with the reference and comparison data of the concentration of phosphoric acid to confirm the concentration of phosphoric acid in the mixed solution; therefore, based on the electrochemical method, it can quickly and accurately measure the concentration of phosphoric acid.

Description

Method for producing test strip and method for detecting phosphoric acid concentration

The invention relates to a detection method, in particular to a method for producing a test strip and a method for detecting the concentration of phosphoric acid.

In order to produce uniform and consistent nano-holes, anodization is a common method of use. It uses aluminum alloy as the anode and etches the nano-structure on the surface of aluminum metal through an electrochemical etching mode. The uniformity and quality of the nano-structures have a great relationship with the concentration of the acid used in the reaction. Therefore, how to detect the concentration of phosphoric acid is an important issue.

Current detection methods include detection using an ion-selective electrode, such as "Phosphate ion selective electrode and manufacturing method thereof" in US Patent No. 6540894, which uses a metal salt that is slightly soluble in water as a sensing film, and Low concentration of phosphate ions can be measured. In addition, it can also be detected by spectrophotometer or liquid chromatography mass spectrometer. The spectrophotometer uses the proportional relationship between absorbance and phosphate concentration to quantify phosphate, and The liquid chromatography mass spectrometer is used to separate impurities through different columns, and then use spectral measurement on the separated liquid to analyze the concentration of the characteristic waveform of phosphoric acid through different peak signals.

However, ion-selective electrodes and spectrophotometers have no measurement specificity for phosphoric acid, and are easily affected by other acids, which can generate noise and cause misjudgment of concentration. Liquid chromatography mass spectrometers require longer processing times. It is not conducive to industrial use. Therefore, how to quickly and accurately measure the concentration of phosphoric acid is a problem that related industry wants to solve.

The main purpose of the present invention is to solve the problem that the concentration of phosphoric acid cannot be measured quickly and accurately.

To achieve the above object, the present invention provides a method for manufacturing a test strip, including the following steps: S1: forming a copper electrode on a first region of a substrate, the copper electrode including a working electrode, a reference electrode, and a Auxiliary electrode, the working electrode includes a first working end and a first reading end far from the first working end; S2: forming a first nickel layer on one side of the first working end away from the substrate; S3: using Forming a first gold layer on the side of the first nickel layer away from the substrate by immersing nickel into gold; and S4: forming an insulating layer on a second region of one of the substrates adjacent to the first region The insulating layer covers the periphery of the first gold layer away from one side of the first nickel layer.

In addition, the present invention further provides a detection method for detecting the concentration of phosphoric acid by using a test strip, which includes the following steps: Q1: Obtain the redox potential of phosphoric acid by cyclic voltammetry, and according to different known concentrations of Phosphoric acid aqueous solution establishes reference information of phosphoric acid concentration; Q2: Obtain a mixed aqueous solution of unknown concentration mixed with the phosphoric acid, titrate the mixed aqueous solution onto the test strip; Q3: apply the redox potential to the test strip, To obtain the current signal of the mixed aqueous solution; and Q4: compare the current signal with the reference concentration data of the phosphoric acid concentration to confirm the concentration of the phosphoric acid in the mixed aqueous solution.

In summary, the present invention has the following characteristics:

First, by dropping the mixed aqueous solution on the test strip, and then applying the redox potential to obtain the current signal, the concentration of phosphoric acid can be compared and obtained, which has the advantage of being fast and accurate.

2. By covering the periphery of the first gold layer away from one side of the first nickel layer with the insulating layer, it is possible to prevent the first nickel layer and the copper electrode from being exposed, thereby affecting the measurement accuracy.

3. The test strip is a low-cost disposable electrode, and does not require the use of expensive instruments, such as a spectrophotometer or a liquid chromatography mass spectrometer, which can reduce costs.

The detailed description and technical contents of the present invention are described below with reference to the drawings:

Please refer to "Figure 1" to "Figure 3F" for the method of making test strips. For a clearer explanation, "Figure 3A" to "Figure 3F" are explained using the AA section in "Figure 2", and The production method includes the following steps:

Step S1: As shown in FIG. 3A, a copper electrode 20 is formed on a first region 11 of a substrate 10, and the copper electrode 20 includes a working electrode 21, a reference electrode 22, and an auxiliary electrode 23, and The working electrode 21 includes a first working end 211 and a first reading end 212 far from the first working end 211. The method for forming the copper electrode 20 may be screen printing, or a copper layer may be formed on the substrate 10 and then etched to form the copper electrode 20, but not limited thereto. In this embodiment, the following steps are further included:

Step S1A: forming the copper electrode 20 before the first region 11 of the substrate 10.

Step S1B: As shown in FIG. 3B, an isolation layer 60 is formed on a second region 12 of the substrate 10, and the isolation layer 60 contacts the copper electrode 20, and the second region 12 is adjacent In the first region 11, in this embodiment, the thickness formed by the isolation layer 60 is thicker than the copper electrode 20, but the isolation layer 60 may be thinner than the copper electrode 20.

Step S2: As shown in FIG. 3C, a first nickel layer 31 is formed on one side of the first working end 211 away from the substrate 10. The method for forming the first nickel layer 31 may be electroless plating (Electroless plating). ) And so on. In this embodiment, the following steps are further included:

Step S2A: forming the first nickel layer 31 on one side of the first working end 211 away from the substrate 10.

Step S2B: forming a second nickel layer 32 on one side of the second working end 221 of the reference electrode 22 away from one side of the substrate 10, and the reference electrode 22 further includes a second readout far from the second working end 221端 222.

Step S2C: forming a third nickel layer 33 on one side of the third working end 231 of the auxiliary electrode 23 away from the substrate 10. Wherein, the first nickel layer 31, the second nickel layer 32, and the third nickel layer 33 may be formed at the same time, and the auxiliary electrode 23 further includes a third reading end 232 far from the third working end 231, Since the first reading end 212, the second reading end 222, and the third reading end 232 do not need to be in contact with the detection liquid, it is not necessary to form a nickel layer thereon.

Step S3: As shown in FIG. 3D, a first gold layer 41 is formed on the side of the first nickel layer 31 away from the substrate 10 by immersing the nickel with gold. In the gold solution, while the electrons are lost through the first nickel layer 31, gold is deposited on the first nickel layer 31 to form the first gold layer 41. In this embodiment, the following steps are further included:

Step S3A: forming the first gold layer 41 on one side of the first nickel layer 31 away from the substrate 10.

Step S3B: A second gold layer 42 is formed at one end of the second nickel layer 32 away from one side of the substrate 10.

Step S3C: A third gold layer 43 is formed at one end of the third nickel layer 33 away from one side of the substrate 10. The first gold layer 41, the second gold layer 42, and the third gold layer 43 may be formed at the same time. After this step, the following steps are included:

Step P1: As shown in FIG. 3E, a second conductive layer 72 is formed on one side of the second gold layer 42 away from the substrate 10. The material of the second conductive layer 72 may be silver, silver chloride, or the like. combination. The second conductive layer 72 may be formed by screen printing.

Step P2: A third conductive layer 73 is formed on one side of the third gold layer 43 away from the substrate 10, and the material of the third conductive layer 73 is carbon, platinum, or a combination thereof. The third conductive layer 73 can be formed by screen printing.

Step S4: As shown in FIG. 3F, an insulating layer 50 is formed on a second region 12 of one of the substrates 10 adjacent to the first region 11, and the insulating layer 50 is upward from the second region 12. It extends and covers the periphery of the first gold layer 41 away from one side of the first nickel layer 31. In this way, the first nickel layer 31 and the copper electrode 20 can be prevented from being exposed, which affects the accuracy of the measurement degree. In this embodiment, the insulation layer 50 is formed on the isolation layer 60, and the materials of the insulation layer 50 and the isolation layer 60 may be the same, as long as they do not react with other materials. However, as shown in FIG. 4, in other embodiments, the insulation layer 50 may be formed without forming the isolation layer 60, so that the insulation layer 50 and the copper electrode 20, the first nickel layer 31 and the The periphery of the first gold layer 41 is in contact with and covers the periphery of the first gold layer 41 away from one side of the first nickel layer 31.

When in use, drop the detection liquid to the first working end 211, the second working end 221 and the third working end 231, and connect a detection instrument (not shown) to the first reading end 212, the first The two reading ends 222 and the third reading end 232 can perform measurement.

Continued with reference to "Figure 5" to "Figure 7", in order to measure the concentration of phosphoric acid using the test strip made by the aforementioned method, it includes the following steps:

Step Q1: Obtain the redox potential of phosphoric acid by using cyclic voltammetry, and establish reference information of monophosphoric acid concentration according to different known concentrations of phosphoric acid aqueous solution. In this embodiment, the following steps are further included:

Step Q1A: Use a cyclic voltammetry (CV) to obtain the redox potential of the phosphoric acid.

Step Q1B: formulate the phosphoric acid aqueous solutions of different known concentrations, and apply the redox potential to the phosphoric acid aqueous solutions using a chronoamperometry to obtain a solution having different currents according to the concentrations of the phosphoric acid aqueous solutions. Phosphoric acid current response data, and the phosphoric acid current response data is shown in "Figure 6". The concentrations of line A, line B, line C, line D, and line E are 0.003% wt, 0.03% wt, 0.15% wt, and 0.3%, respectively. wt, 0.9% wt.

Step Q1C: Establish the phosphoric acid concentration reference comparison data according to the phosphoric acid current response data. Please refer to "Figure 6", and use the appropriate time as a reference line, for example, 2.5 seconds, and obtain the corresponding currents of the phosphoric acid aqueous solutions with different concentrations, and further prepare current comparison data of concentration. The reference comparison data of the phosphoric acid concentration as shown in FIG. 7 can be formed, and the linear correlation coefficient (R ² ) is 0.9767. Therefore, it has a very accurate basis.

Step Q2: Obtain a mixed aqueous solution mixed with the phosphoric acid, the concentration of which is unknown, and titrate the mixed aqueous solution onto the test strip.

Step Q3: Apply the redox potential to the test strip to obtain a current signal of the mixed aqueous solution, and the redox potential of phosphoric acid measured by cyclic voltammetry is 0.15 volts. In addition, when 0.14 volts or 0.16 volts are applied, the linear correlation coefficients (R ² ) are 0.2651 and 0.3014, respectively. Therefore, it can be known that when 0.15 volts are applied, it has good specificity for detecting a phosphoric acid solution.

Step Q4: Compare the current signal with the reference data of the phosphoric acid concentration to confirm the concentration of the phosphoric acid in the mixed aqueous solution. And with reference to "Figure 7", if the current signal is 20 μA, the concentration of phosphoric acid can be determined to be 0.22% wt. In this way, using this method can quickly and accurately measure the concentration of phosphoric acid (result signal RSD = 1.5% or less).

In summary, the present invention has the following characteristics:

First, by titrating the mixed aqueous solution onto the test strip and applying the current signal obtained by applying the redox potential, the concentration of phosphoric acid can be measured quickly and accurately.

2. By covering the periphery of the first gold layer away from one side of the first nickel layer with the insulating layer, it is possible to prevent the first nickel layer and the copper electrode from being exposed, thereby affecting the measurement accuracy.

3. The test strip is a low-cost disposable electrode and does not require the use of expensive instruments such as a spectrophotometer or a liquid chromatography mass spectrometer, which can reduce costs.

Therefore, the present invention is highly progressive and meets the requirements for applying for an invention patent. The application was submitted in accordance with the law.

The present invention has been described in detail above, but the above is only a preferred embodiment of the present invention, and the scope of implementation of the present invention cannot be limited. That is, all equivalent changes and modifications made in accordance with the scope of the application of the present invention should still fall within the scope of the patent of the present invention.

10‧‧‧ substrate
11‧‧‧ first zone
12‧‧‧ second zone
20‧‧‧ Copper electrode
21‧‧‧Working electrode
211‧‧‧First client
212‧‧‧first read end
22‧‧‧Reference electrode
221‧‧‧Second working end
222‧‧‧Second reading terminal
23‧‧‧Auxiliary electrode
231‧‧‧ third terminal
232‧‧‧Third reading terminal
31‧‧‧The first nickel layer
32‧‧‧second nickel layer
33‧‧‧ Third nickel layer
41‧‧‧The first gold layer
42‧‧‧Second Golden Layer
43‧‧‧ Third Golden Layer
50‧‧‧ Insulation
60‧‧‧Isolation
72‧‧‧ second conductive layer
73‧‧‧ third conductive layer
S1 ~ S4, S1A ~ S1C, S2A ~ S2C, S3A ~ S3C, P1, P2, Q1 ~ Q4, Q1A ~ Q1C‧‧‧Steps
A ~ E‧‧‧Segments

FIG. 1 is a schematic flowchart of a first embodiment of the present invention. FIG. 2 is a schematic view of the three-dimensional structure of the first embodiment of the present invention. 3A to 3F are schematic diagrams of a manufacturing process according to the first embodiment of the present invention. FIG. 4 is a schematic cross-sectional view of a second embodiment of the present invention. FIG. 5 is a schematic flowchart of a third embodiment of the present invention. FIG. 6 is a schematic diagram of current response data according to a third embodiment of the present invention. FIG. 7 is a schematic diagram of concentration reference comparison data according to a third embodiment of the present invention.

Q1 ~ Q4, Q1A ~ Q1C‧‧‧steps

Claims (8)

A method for manufacturing a test strip includes the following steps: S1: A copper electrode is formed on a first region of a substrate. The copper electrode includes a working electrode, a reference electrode, and an auxiliary electrode. The working electrode includes a working electrode. A first working end and a first reading end far from the first working end; S2: forming a first nickel layer on a side of the first working end away from the substrate; S3: formed by immersing nickel into gold A first gold layer on one side of the first nickel layer away from the substrate; and S4: forming an insulating layer on a second region of one of the substrates adjacent to the first region, the insulating layer covering the first layer A gold layer is far from the periphery of one side of the first nickel layer. The method for manufacturing a test strip as described in item 1 of the patent application scope, wherein in step S1, the method further includes the following steps: S1A: forming the copper electrode on the first region of the substrate; and S1B: on the substrate An isolation layer is formed in a second region of the substrate, and the isolation layer is in contact with the copper electrode. The method for manufacturing a test strip as described in item 1 of the scope of patent application, wherein step S2 further includes the following steps: S2A: forming the first nickel layer on a side of the first working end away from the substrate; S2B: forming a second nickel layer on one side of the reference electrode away from one side of the substrate; and S2C: forming a third nickel layer on one side of the auxiliary electrode away from one side of the substrate . The method for manufacturing a test strip as described in item 3 of the patent application scope, further comprising the following steps in step S3: S3A: forming the first gold layer on a side of the first nickel layer away from the substrate; S3B: forming a second gold layer on the side of the second nickel layer away from one side of the substrate; and S3C: forming a third gold layer on the side of the third nickel layer away from one side of the substrate. The method for manufacturing a test strip as described in item 4 of the scope of patent application, further comprising the following steps after step S3: P1: forming a second conductive layer on a side of the second gold layer away from the substrate, The material of the second conductive layer is selected from the group consisting of silver and silver chloride; and P2: a third conductive layer is formed on one side of the third gold layer away from the substrate. The material is selected from the group consisting of carbon and platinum. A method for detecting the concentration of phosphoric acid by using a test strip such as the first item in the scope of patent application, which includes the following steps: Q1: Use a cyclic voltammetry to obtain the redox potential of monophosphoric acid, and according to different known concentrations of phosphoric acid A reference solution for the concentration of phosphoric acid was established in the aqueous solution. Q2: Obtain a mixed aqueous solution of unknown concentration mixed with the phosphoric acid, and titrate the mixed aqueous solution onto the test strip; Q3: Apply the redox potential to the test strip, Obtaining the current signal of the mixed aqueous solution; and Q4: comparing the current signal with reference information of the phosphoric acid concentration to confirm the concentration of the phosphoric acid in the mixed aqueous solution. The method for detecting the concentration of phosphoric acid as described in item 6 of the scope of patent application, wherein in step Q1, the method further includes the following steps: Q1A: obtaining the redox potential of the phosphoric acid; Q1B: formulating the different known concentrations of these Phosphoric acid aqueous solution, and applying the oxidation-reduction potential to the phosphoric acid aqueous solutions by using chronoamperometry to obtain phosphoric acid current response data having different current changes according to the concentration of the phosphoric acid aqueous solutions; and Q1C: according to the phosphoric acid current response data, Establish a reference comparison of the phosphoric acid concentration. The method for detecting the concentration of phosphoric acid as described in item 6 of the patent application scope, wherein in step Q1, the redox potential is 0.15 volts.