CN108195902B - Metal sulfide ore biosensor and use method thereof - Google Patents

Abstract

The invention relates to a metal sulfide ore biosensor and a method of using the same, comprising a cylinder-shaped sensing element and a copper wire connected to the bottom surface of one end of the cylinder. The sensing element is metal sulfide ore, and the sensing element and the copper wire are covered with Polytetrafluoroethylene, the bottom surface of one end of the sensing element that is not covered with polytetrafluoroethylene is the detection end that is in contact with the solution to be tested, and the solution to be tested is hydrogen peroxide, ascorbic acid or glucose solution. Its use method is to use the metal sulfide ore biosensor as the working electrode, establish a three-electrode system of working electrode, counter electrode and reference electrode, and connect it with the electrochemical workstation; then place the detection end of the working electrode in the solution to be tested, and pass The electrochemical workstation detects the magnitude of the response current in the solution to be tested, and then determines the concentration of biological components in the solution to be tested according to the standard curve. The invention has the advantages of simple structure, low pollution, low cost, fast response speed, wide detection range and good operation stability.

Description

A kind of metal sulfide ore biosensor and using method thereof

technical field

The invention belongs to the technical field of biosensors for detecting biomedical data, and particularly relates to a metal sulfide ore biosensor using natural metal sulfide ore as a working electrode and a method for using the same.

Background technique

In recent decades, most biosensors immobilize biological enzymes on electrodes to detect corresponding substrates. The purification process of the biological enzyme itself is very difficult, and the process of immobilizing the biological enzyme on the electrode is also cumbersome, complicated, and costly, and because the biological enzyme is easily affected by the external environment and loses its activity, the biological enzyme sensor has poor stability and short service life, etc. shortcoming. With the rapid development of science and technology, biosensors have developed to the fourth generation, that is, enzyme-free sensors. The enzyme-free sensor has the following advantages: 1. The preparation becomes relatively simple and easy to operate; 2. The service life is relatively long and the stability is better; 3. Under the condition of no enzyme, the influence of dissolved oxygen on some substrates is avoided. . Therefore, compared with enzymatic electrochemical biosensors, non-enzymatic electrochemical biosensors have attracted extensive attention due to their wide detection linearity, better stability, lower cost, and longer service life.

Glucose detection methods include spectroscopy, chromatography, and electrochemical methods. Among them, electrochemical glucose sensors are widely used due to their fast detection speed, high sensitivity, low cost, and easy operation.

Publication (Publication) No.: CN106198654A, which discloses "electrochemical non-enzyme electrochemical glucose sensor electrode material and its preparation method and application", provides a nickel- _doped FeS coating material, which is coated on conductive On glass, the prepared glucose sensor has the advantages of wide detection range, strong anti-interference, and low cost. However, its preparation method is relatively complicated, and it needs to use various raw materials of mixed solution of ferrous salt, nickel salt, citrate, polyvinylpyrrolidone, sodium hydroxide solution, sulfur powder and water to obtain by hydrothermal method, and in the preparation process It needs to be carried out at high temperature in the autoclave for 20-48 hours.

Hydrogen peroxide (H ₂ O ₂ ) can be used as an oxidant in the medical, pharmaceutical and food industries, and is also a mediator in many biological systems; however, excess hydrogen peroxide can cause damage to the human central nervous system. At present, there are many methods for detecting hydrogen peroxide, such as titration, spectrophotometry and electrochemical methods. Among them, the electrochemical method for detecting hydrogen peroxide has the advantages of high sensitivity, good selectivity and simple method, and is widely used in the determination of hydrogen peroxide.

Publication (Publication) No.: CN102735732A, which discloses "Preparation and Application of Nanometer Cuprous Oxide Non-enzyme Hydrogen Peroxide Sensor Electrode". Through cuprous oxide nanowires and Nafion modified gold electrodes, the catalytic properties of cuprous oxide are used to detect the content of hydrogen peroxide, and the rapid electrochemical determination of hydrogen peroxide is realized, with low detection limit, high sensitivity and good stability. advantage. The preparation process of this sensor is relatively complicated, requiring electrodeposition and removing the alumina template in an alkaline solution, and the cuprous oxide nanowires and gold electrodes used are expensive and not suitable for industrialization.

Publication (Publication) No.: CN105738440A, which discloses "a gold nanoarray electrode and an enzyme-free hydrogen peroxide sensor prepared therefrom". In this patent, a silicon-based single-layer polymer colloidal crystal array is prepared, a gold film is deposited on the surface of the template by a physical deposition method, and then the template is thermally decomposed and annealed to obtain a silicon-based nanoarray. The prepared electrode has high sensitivity and stability. good, economical and environmentally friendly. This preparation method has the disadvantages of complicated steps, high cost, and the need to use an organic solvent, which is not conducive to environmental protection.

L-ascorbic acid (vitamin C, Vc for short) can block the formation of carcinogen ammonium nitrite. Lack of Vc will cause scurvy, and excessive Vc will also have adverse effects on the human body. For the determination of its content, electrochemical sensors are mostly used. The electrochemical sensor device and use method are more complicated.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a metal sulfide ore biosensor using natural metal sulfide ore as a sensing element and a method of using the same in order to solve the problems that the preparation process of the enzyme-free sensor is still complicated and the cost is still high.

In order to achieve the above object, technical scheme of the present invention is as follows:

A metal sulfide ore biosensor of the present invention comprises a cylinder-shaped sensing element and a copper wire connected to the bottom surface of one end of the cylinder, and is characterized in that: the sensing element is metal sulfide ore, and the side of the cylinder is packaged There is polytetrafluoroethylene, the copper wire and the bottom surface connected with the copper wire are also encapsulated with polytetrafluoroethylene, and the bottom surface of the other end is the detection end that is in contact with the solution to be tested.

The induction element is a polished, cleaned and processed natural metal sulfide ore, and its diameter is 3mm-8mm, and its height is 3mm-8mm.

The metal sulfide minerals include natural pyrite, natural chalcopyrite, natural galena and natural molybdenite.

The metal sulfide mineral biosensor is used for quantitatively detecting biological components in biological samples, and the biological components include hydrogen peroxide, ascorbic acid or glucose.

The application of a natural metal sulfide ore of the present invention is characterized in that it is used for quantitatively detecting biological components in biological samples, and the biological components include hydrogen peroxide, ascorbic acid or glucose.

A method of using a metal sulfide ore biosensor of the present invention is characterized in that it comprises the following steps:

(1) Using the metal sulfide ore biosensor as the working electrode, the platinum electrode as the counter electrode, and the silver/silver chloride as the reference electrode, a three-electrode system is established, and the three-electrode system is connected to the electrochemical workstation;

(2) placing the detection end of the metal sulfide ore biosensor in the solution to be measured, and detecting the response current of the biological components in the solution to be measured by the electrochemical workstation, and then according to the difference between the response current and the concentration of biological components Standard curve to determine the concentration of biological components in the solution to be tested.

The principle of the present invention is that almost all metal sulfide minerals in nature have semiconductor properties and have electrical conductivity. Based on this feature, the present invention directly uses natural metal sulfide ore as the sensing element of the biosensor to quantitatively detect hydrogen peroxide, ascorbic acid or glucose in biological samples.

Compared with the prior art, the present invention has the following advantages:

1. The preparation method of the metal sulfide ore biosensor is simple, the pollution is small, and the cost is low.

2. The metal sulfide ore biosensor has fast response speed, wide detection range, good operation stability and long service life for the biological components to be measured.

Description of drawings

Figure 1 is a schematic diagram of the structure of the metal sulfide ore biosensor.

Among them, 1. copper wire, 2. PTFE, 3. induction element.

Figure 2 is a schematic diagram of the metal sulfide ore biosensor detection system.

Among them, 4. Working electrode, 5. Counter electrode, 6. Reference electrode, 7. Solution to be tested, 8. Electrochemical workstation.

Figure 3 is a standard curve of the relationship between the response current of the pyrite biosensor and the concentration of hydrogen peroxide.

Figure 4 is a standard curve of the relationship between the response current of the chalcopyrite biosensor and the concentration of hydrogen peroxide.

Figure 5 is a standard curve of the relationship between the response current of the pyrite biosensor and the concentration of ascorbic acid.

Figure 6 is a standard curve of the relationship between the response current of the chalcopyrite biosensor and the concentration of ascorbic acid.

Figure 7 is a standard curve of the relationship between the response current of the galena biosensor and the concentration of hydrogen peroxide.

Figure 8 is the standard curve of the relationship between the response current and the glucose concentration of the galena biosensor.

Figure 9 is a standard curve of the response current of the molybdenite biosensor versus glucose concentration.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings.

The raw materials used in the following examples are all commercially available, the metal sulfide ore is purchased from Shanxi Province, and the polytetrafluoroethylene is purchased from Tianjin Aida Hengsheng Technology Development Co., Ltd.

Example 1

As shown in Figures 1-2, the metal sulfide ore biosensor includes a cylindrical sensing element 3 and a copper wire 1 connected to the bottom surface of one end of the cylinder. It is characterized in that: the sensing element 3 is metal sulfide ore, so The side of the cylinder is encapsulated with polytetrafluoroethylene 2, the copper wire 1 and the bottom surface connected with the copper wire 1 are also encapsulated with polytetrafluoroethylene 2, and the bottom surface of the other end is the detection end in contact with the solution to be tested.

The induction element 3 is a metal sulfide ore that has been polished and cleaned, with a diameter of 5 mm and a height of 5 mm.

The metal sulfide ores are respectively pyrite, chalcopyrite, galena and molybdenite.

As shown in Figure 2, the use method of the metal sulfide ore biosensor, the detection steps are as follows:

(1) using the metal sulfide ore biosensor as the working electrode 4, the platinum electrode as the counter electrode 5, and the silver/silver chloride as the reference electrode 6, a three-electrode system is established, and the three-electrode system is connected with the electrochemical workstation 8;

(2) The detection end of the working electrode 4 is placed in the solution 7 to be tested, and the electrochemical workstation 8 detects the size of the response current of the biological components in the solution 7 to be tested by the sensor, and then according to the standard of the response current and the concentration of biological components curve to determine the concentration of biological components in solution 7 to be tested.

Example 2

As shown in Figure 2, the steps of the pyrite biosensor to detect the concentration of hydrogen peroxide are as follows:

(1) with the pyrite biosensor as the working electrode 4, the platinum electrode as the counter electrode 5, and the silver/silver chloride as the reference electrode 6, a three-electrode system is established, and the three-electrode system is connected with the electrochemical workstation 8;

Working conditions: The electrolyte used is sodium hydroxide (NaOH) solution, the concentration of NaOH is 100mM, and the voltage is -0.6V. Under these conditions, the pyrite biosensor has the largest response current to the concentration of hydrogen peroxide.

(2) the detection end of the working electrode 4 is placed in the hydrogen peroxide solution 7, and the pyrite biosensor in the hydrogen peroxide solution 7 is detected by the electrochemical workstation 8 in response to the current size of the hydrogen peroxide concentration, and then according to the response Standard curve of current versus hydrogen peroxide concentration to determine hydrogen peroxide concentration in hydrogen peroxide solution 7.

The standard curve of the relationship between the response current of the pyrite biosensor and the concentration of hydrogen peroxide is shown in Figure 3.

Specific selectivity investigation of pyrite biosensors:

Using the same concentration of uric acid, glucose and fructose as hydrogen peroxide for detection, the pyrite biosensor has no obvious detection signal for these three substrates, and the pyrite biosensor has better selectivity.

The detection performance of pyrite biosensor for hydrogen peroxide is shown in Table 1:

Table 1 Detection performance of pyrite biosensors for hydrogen peroxide

Example 3

As shown in Figure 2, the steps of the chalcopyrite biosensor to detect the hydrogen peroxide concentration are as follows:

(1) use chalcopyrite biosensor as working electrode 4, platinum electrode as counter electrode 5, silver/silver chloride as reference electrode 6, establish three-electrode system, and three-electrode system is connected with electrochemical workstation 8;

Working conditions: The electrolyte used is sodium hydroxide (NaOH) solution, the concentration of NaOH is 100mM, and the voltage is -0.4V. Under these conditions, the chalcopyrite biosensor has the largest response current to the concentration of hydrogen peroxide.

(2) the detection end of the working electrode 4 is placed in the hydrogen peroxide solution 7, and the electrochemical workstation 8 detects the size of the chalcopyrite biosensor in the hydrogen peroxide solution 7 in response to the hydrogen peroxide concentration, and then according to the response Standard curve of current versus hydrogen peroxide concentration to determine hydrogen peroxide concentration in hydrogen peroxide solution 7.

The standard curve of the relationship between the response current of the chalcopyrite biosensor and the concentration of hydrogen peroxide is shown in Figure 4.

Specific selectivity investigation of chalcopyrite biosensors:

Using the same concentration of uric acid, glucose and fructose as hydrogen peroxide for detection, the chalcopyrite biosensor has no obvious detection signal for these three substrates, and the chalcopyrite biosensor has good selectivity.

The detection performance of chalcopyrite biosensor for hydrogen peroxide is shown in Table 2:

Table 2 The detection performance of chalcopyrite biosensor for hydrogen peroxide

Example 4

As shown in Figure 2, the steps of the pyrite biosensor to detect the concentration of ascorbic acid (Vc) are as follows:

(1) with the pyrite biosensor as the working electrode 4, the platinum electrode as the counter electrode 5, and the silver/silver chloride as the reference electrode 6, a three-electrode system is established, and the three-electrode system is connected with the electrochemical workstation 8;

Working conditions: The electrolyte used is sodium hydroxide (NaOH) solution, the NaOH concentration is 100mM, and the voltage is -0.05V. Under this condition, the pyrite biosensor has the largest and stable response current to the ascorbic acid concentration.

(2) the detection end of the working electrode 4 is placed in the detection ascorbic acid (Vc) solution 7, and the pyrite biosensor in the ascorbic acid (Vc) solution 7 is detected by the electrochemical workstation 8 The size of the ascorbic acid (Vc) concentration response current, The ascorbic acid (Vc) concentration in the ascorbic acid (Vc) solution 7 was then determined from a standard curve of response current versus ascorbic acid concentration.

The standard curve of the relationship between the response current of the pyrite biosensor and the ascorbic acid concentration is shown in Figure 5.

Specific selectivity investigation of pyrite biosensors:

Using the same concentration of uric acid, glucose and fructose as ascorbic acid (Vc) for detection, the pyrite biosensor has no obvious detection signal for these three substrates, and the pyrite biosensor has better selectivity.

The detection performance of pyrite biosensor ascorbic acid is shown in Table 3:

Table 3 Detection performance of pyrite biosensors for ascorbic acid

Example 5

As shown in Figure 2, the steps of the chalcopyrite biosensor to detect the concentration of ascorbic acid (Vc) are as follows:

(1) use chalcopyrite biosensor as working electrode 4, platinum electrode as counter electrode 5, silver/silver chloride as reference electrode 6, establish three-electrode system, and three-electrode system is connected with electrochemical workstation 8;

Working conditions: The electrolyte used is sodium hydroxide (NaOH) solution, the NaOH concentration is 100mM, and the voltage is -0.05V. Under this condition, the chalcopyrite biosensor responds to the ascorbic acid concentration with the largest and stable current.

(2) the detection end of the working electrode 4 is placed in the ascorbic acid (Vc) solution 7, and the ascorbic acid (Vc) concentration response current of the chalcopyrite biosensor in the ascorbic acid (Vc) solution 7 is detected by the electrochemical workstation 8, The ascorbic acid (Vc) concentration in the ascorbic acid (Vc) solution 7 was then determined from a standard curve of response current versus ascorbic acid concentration.

The standard curve of the relationship between the response current of the chalcopyrite biosensor and the ascorbic acid concentration is shown in Figure 6.

Specific selectivity investigation of chalcopyrite biosensors:

Using the same concentration of uric acid, glucose and fructose as ascorbic acid (Vc) for detection, the chalcopyrite biosensor has no obvious detection signal for these three substrates, and the chalcopyrite biosensor has better selectivity.

The detection performance of chalcopyrite biosensor ascorbic acid is shown in Table 4:

Table 4 Detection performance of chalcopyrite biosensors for ascorbic acid

Example 6

As shown in Figure 2, the steps of the galena biosensor to detect the concentration of hydrogen peroxide are as follows:

(1) with the galena biosensor as the working electrode 4, the platinum electrode as the counter electrode 5, and the silver/silver chloride as the reference electrode 6, a three-electrode system is established, and the three-electrode system is connected with the electrochemical workstation 8;

Working conditions: The electrolyte used is sodium hydroxide (NaOH) solution, the NaOH concentration is 100mM, and the voltage is -0.4V. Under this condition, the lead ore biosensor has the largest and stable response current to the hydrogen peroxide concentration.

(2) the detection end of the working electrode 4 is placed in the hydrogen peroxide solution 7, and the electrochemical workstation 8 detects the size of the response current of the galena biosensor in the hydrogen peroxide solution 7 to the hydrogen peroxide concentration, and then according to the response current Determine the hydrogen peroxide concentration in the hydrogen peroxide solution 7 with the standard curve of the hydrogen peroxide concentration.

The standard curve of the relationship between the response current of the galena biosensor and the concentration of hydrogen peroxide is shown in Figure 7.

Specific Selective Investigation of Galena Biosensors:

Using the same concentration of uric acid, ascorbic acid and catechol as hydrogen peroxide for detection, the galena biosensor has no obvious detection signal for these three substrates, and the galena biosensor has good selectivity.

The detection performance of galena biosensor for hydrogen peroxide is shown in Table 5:

Table 5 Detection performance of galena biosensor for hydrogen peroxide

Example 7

As shown in Figure 2, the steps for the galena biosensor to detect glucose concentration are as follows:

(1) with the galena biosensor as the working electrode 4, the platinum electrode as the counter electrode 5, and the silver/silver chloride as the reference electrode 6, a three-electrode system is established, and the three-electrode system is connected with the electrochemical workstation 8;

Working conditions: The electrolyte used is sodium hydroxide (NaOH) solution, the NaOH concentration is 100mM, and the voltage is 0.4V. Under these conditions, the lead mine biosensor has the largest and stable response current to the glucose concentration.

(2) place the detection end of the working electrode 4 in the glucose solution 7, detect the magnitude of the response current of the galena biosensor in the glucose solution 7 to the glucose concentration by the electrochemical workstation 8, and then according to the standard curve of the response current and the glucose concentration , to determine the glucose concentration in the glucose solution 7.

The standard curve of the relationship between the response current and the glucose concentration of the galena biosensor is shown in Figure 8.

Specific Selective Investigation of Galena Biosensors:

Using the same concentrations of uric acid, ascorbic acid and catechol as glucose for detection, the galena biosensor has no obvious detection signal for these three substrates, and the galena biosensor has good selectivity.

The detection performance of galena biosensor for glucose is shown in Table 6:

Table 6 The detection performance of galena biosensor for glucose

Example 8

As shown in Figure 2, the steps for the molybdenite biosensor to detect glucose concentration are as follows:

(1) using the molybdenite biosensor as the working electrode 4, the platinum electrode as the counter electrode 5, and the silver/silver chloride as the reference electrode 6, a three-electrode system is established, and the three-electrode system is connected with the electrochemical workstation 8;

Working conditions: The electrolyte used is sodium hydroxide (NaOH) solution, the NaOH concentration is 100 mM, and the voltage is 0.4 V. Under these conditions, the molybdenite biosensor is stable in response to the glucose concentration.

(2) place the detection end of the working electrode 4 in the glucose solution 7, detect the magnitude of the response current of the molybdenite biosensor in the glucose solution 7 to the glucose concentration by the electrochemical workstation 8, and then according to the standard of the response current and the glucose concentration Curve to determine the glucose concentration in the glucose solution 7.

The standard curve of the relationship between the response current and the glucose concentration of the molybdenite biosensor is shown in Figure 9.

Specific selectivity investigation of molybdenite biosensors:

Using the same concentration of uric acid, hydrogen peroxide, ascorbic acid and catechol as glucose for detection, the molybdenite biosensor has no obvious detection signal for these four substrates, and the molybdenite biosensor has good selectivity .

The detection performance of molybdenite biosensor for glucose is shown in Table 7:

Table 7 The detection performance of molybdenite biosensor for glucose

Claims (3)

1. The use method of the metal sulfide ore biosensor is characterized by comprising the following steps:

(1) establishing a three-electrode system by taking the metal sulfide ore biosensor as a working electrode, a platinum electrode as a counter electrode and silver/silver chloride as a reference electrode, wherein the three-electrode system is connected with an electrochemical workstation;

metal sulphide ore biosensor, including the response original paper of cylinder type and the copper line that links to each other with cylinder one end circle cross-section, its characterized in that: the sensing element is a metal sulfide mineral, polytetrafluoroethylene is packaged on the side face of the cylinder, polytetrafluoroethylene is packaged on the copper wire and the circular section connected with the copper wire, the other circular section is a detection end in contact with a solution to be detected, and the metal sulfide mineral is a natural square lead mineral or a natural molybdenite;

(2) and placing the detection end of the metal sulfide ore biosensor in a solution to be detected, detecting the response current of the sensor to a certain biological component in the solution to be detected through an electrochemical workstation, and determining the concentration of the biological component in the solution to be detected according to the standard curve of the concentration of the biological component and the response current.

2. The use method of the metal sulfide ore biosensor as claimed in claim 1, wherein the sensing element is a polished, cleaned and processed natural metal sulfide mineral with a diameter of 3 mm-8 mm and a height of 3 mm-8 mm.

3. The method as claimed in claim 1, wherein the metal sulfide ore biosensor is used for quantitative detection of biological components in a biological sample, and the biological components include hydrogen peroxide, ascorbic acid or glucose.

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