PH-type electrochemical luminescence sensor based on copper indium sulfide / carbazide system and preparation method of pH-type electrochemical luminescence sensor

Abstract

The invention relates to a pH type electrochemical luminescence sensor based on a copper-indium-sulfur / carbazide system and a preparation method. The method comprises the following steps: firstly, synthesizing a core-shell structure copper-indium-sulfur nanocrystal through a one-pot method; the preparation method comprises the following steps: firstly, preparing a copper indium sulfide / carbazide system-based pH-type electrochemical luminescence sensor by using purified copper indium sulfide nanocrystals as illuminants, and under different pH value conditions, the sensor shows obvious pH-dependent electrochemical luminescence, and electrochemical luminescence spectrums of different pH values are all at near-infrared positions and are induced by surface defects. The maximum wavelength of electrochemical luminescence of the material is 743nm of near-infrared light. Under different pH value conditions, obvious anode or cathode electrochemical luminescence signals are shown, corresponding linear correlation is shown, and the pH value of a solution can be quantitatively detected.

Description

Technical Field

[0001] The invention relates to a pH type electrochemiluminescence sensor based on a copper indium sulfur / carbohydrazine system and a preparation method thereof, belonging to the field of analytical technology methods. Background Art

[0002] pH value is one of the most important physical and chemical parameters of aqueous solutions. All natural phenomena, chemical changes and production processes involving aqueous solutions are related to pH.

[0003] In biological systems, pH plays an important role in some physiological processes, such as cell proliferation, enzyme activity, ion transport, the survival state of cancer cells, etc. (J.Am.Chem.Soc., 2009, 131, 3016; Chem.Rev., 2010, 5, 2709.). Therefore, the determination of pH has always been an indispensable task in the fields of industrial and agricultural production, scientific research, clinical medicine, environmental protection and monitoring.

[0004] The pH glass electrode is the most representative chemical sensor for measuring hydrogen ion activity, but due to its high impedance, it is difficult to miniaturize and easy to break. It cannot be used for pH measurement of HF solution. It has defects such as "sodium error" and "acid error", which limits its application in intracellular pH detection and cell imaging research. Electrochemiluminescence sensors are favored by scientific researchers because of their high sensitivity, good selectivity, low detection limit, and simple instrument operation. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a pH-type electrochemiluminescence sensor based on a copper indium sulfur / carbohydrazine system and a preparation method thereof.

[0006] The pH-type electrochemiluminescence sensor based on the copper indium sulfur / carbohydrazine system provided by the present invention has a maximum wavelength of electrochemiluminescence of 743 nm in the near infrared under the condition of carbohydrazine co-reactant. Under different pH conditions, it shows obvious anode or cathode electrochemiluminescence signals and presents a corresponding linear correlation, and can quantitatively detect the pH value of the solution.

[0007] The present invention is achieved through the following technical solutions:

[0008] The preparation method of the pH type electrochemiluminescence sensor based on the copper indium sulfur / carbohydrazine system comprises the following steps:

[0009] (1) mixing a copper chloride solution, an indium chloride solution, a glutathione solid powder and a sodium citrate solution into ultrapure water and stirring them evenly to obtain a mixed solution a; injecting a sodium sulfide solution, the solution changes from colorless to dark yellow, and heating the obtained solution to react to obtain a core structure copper indium sulfur nanocrystal solution;

[0010] (2) mixing thiourea, glutathione and zinc acetate solution into ultrapure water to obtain a mixed solution b, injecting the mixed solution b into the core structure copper indium sulfur nanocrystal solution obtained in step (1), and heating for reaction;

[0011] (3) After heating and reacting, the mixture is purified with isopropanol, and the resulting precipitate is a core-shell structured copper indium sulfur nanocrystal;

[0012] (4) Using the core-shell structure copper indium sulfur nanocrystals purified in step (3) as the luminescent material, placing the indium sulfur core-shell structure nanocrystals on a glassy carbon electrode and drying at room temperature to prepare a pH-type electrochemiluminescence sensor.

[0013] According to the present invention, preferably, in step (1), the concentration of the cupric chloride solution is 0.005-0.02M, the concentration of the indium chloride solution is 4.0-6.0mM, the concentration of the sodium citrate solution is 0.2-0.6M, and the concentration of the sodium sulfide solution is 0.5-2M.

[0014] According to the present invention, preferably, in step (1), the molar ratio of copper chloride: indium chloride: glutathione: sodium sulfide is (40-50): 1: (700-900): (270-470),

[0015] More preferably, the molar ratio of copper chloride:indium chloride:glutathione:sodium sulfide is 45:1:800:370.

[0016] According to the present invention, preferably, in step (1), the molar ratio of indium chloride to sodium citrate is 1:(0.6-20).

[0017] According to the present invention, preferably, in step (1), the volume ratio of the cupric chloride solution to ultrapure water is (0.5-2):(10-30).

[0018] According to the present invention, preferably, in step (1), the heating reaction is carried out at 90-100° C. for 30-60 minutes.

[0019] According to the present invention, preferably, in step (2), the molar ratio of thiourea: zinc acetate: glutathione is (5-15): (8-12): (8-25).

[0020] According to the present invention, preferably, in step (2), the molar ratio of thiourea: zinc acetate: glutathione is 12:10:15.

[0021] According to the present invention, preferably, in step (2), the mass volume ratio of thiourea to ultrapure water is (0.01-0.1):(10-30), unit, g / mL.

[0022] According to the present invention, preferably, in step (2), the volume ratio of the mixed solution b to the core structure copper indium sulfur nanocrystal solution is 1:(3-6).

[0023] According to the present invention, preferably, in step (2), the heating reaction is carried out at 90-100° C. for 20-40 minutes.

[0024] According to the present invention, preferably, in step (3), the isopropanol is purified by adding isopropanol to the solution of step (2) and centrifuging at 13,300 rpm.

[0025] According to the present invention, preferably, in step (4), the concentration of the core-shell structured copper indium sulfide nanocrystals is 0.5-3 mg / mL.

[0026] According to the present invention, preferably, in step (4), the amount of core-shell structured copper indium sulfur nanocrystals used is 9-11 μL.

[0027] The core-shell structure copper indium sulfur nanocrystal aqueous solution obtained in step (3) of the present invention is wine red, the maximum fluorescence emission wavelength of copper indium sulfur under optimal conditions is 645 nm in the near infrared, the fluorescence under ultraviolet light is obvious red, and under the condition of carbohydrazide as a co-reactant, the maximum wavelength of its electrochemical luminescence is 743 nm in the near infrared.

[0028] A preferred embodiment of the present invention

[0029] A method for preparing a pH-type electrochemiluminescence sensor based on a copper indium sulfur / carbohydrazine system comprises the following steps:

[0030] (1) 900 μL of a 0.005-0.02M copper chloride solution, 40 μL of a 4.0-6.0mM indium chloride solution, 0.0062 g of glutathione solid powder and 400 μL of a 0.2-0.6M sodium citrate solution were mixed into 20 mL of ultrapure water and stirred evenly to obtain a mixed solution a; 62 μL of a 0.5-2M sodium sulfide solution was injected, and the solution changed from colorless to dark yellow. The obtained solution was heated at 95° C. for 40 minutes to obtain a copper indium sulfur nanocrystal core structure;

[0031] (2) 0.061 g of thiourea, 0.376 g of glutathione and 0.177 g of zinc acetate solution were mixed in 20 mL of ultrapure water to obtain a mixed solution b; 5 mL of the mixed solution b was injected into the solution obtained in step (1) and heated at 95° C. for 30 minutes;

[0032] (3) centrifuging and purifying the copper indium sulfur nanocrystals obtained in step (2) with isopropanol, and the resulting precipitate is the copper indium sulfur nanocrystals with a core-shell structure;

[0033] (4) Take 9-11 μL of 0.5-3 mg / mL core-shell structure copper indium sulfur nanocrystals prepared in step (3), drop them on a glassy carbon electrode and dry them at room temperature to prepare a pH-type electrochemiluminescence sensor based on the copper indium sulfur / carbohydrazide system.

[0034] A pH-type electrochemiluminescence sensor based on a copper indium sulfur / carbohydrazine system is constructed using the above method.

[0035] The pH-type electrochemiluminescence sensor based on the copper indium sulfur / carbohydrazide system was used as the working electrode and carbohydrazide as the co-reactant. The electrochemiluminescence radiation signal of the anode or cathode was measured under different pH conditions. The electrochemiluminescence signal of the anode of the electrochemiluminescence sensor increased with the increase of pH value, and it showed a linear correlation in the range of electrolyte pH 5-12, R 2 The value is 0.996; the cathode electrochemiluminescence signal of the electrochemiluminescence sensor increases with the decrease of pH value, and is linearly correlated in the range of pH = 1-4 of the electrolyte solution, R 2 The value is 0.992.

[0036] The pH-type electrochemiluminescence sensor exhibits obvious anodic or cathodic electrochemiluminescence signals under different pH conditions, presenting a corresponding linear correlation, and can quantitatively detect the pH value of the solution.

[0037] The application of the pH-type electrochemiluminescence sensor based on the copper indium sulfur / carbohydrazine system is used to quantitatively detect the pH value of a solution.

[0038] According to a preferred embodiment of the present invention, a method for quantitatively detecting the pH value of a solution using a pH-type electrochemiluminescence sensor based on a copper indium sulfur / carbohydrazine system comprises the following steps:

[0039] 1) Using the above-mentioned pH-type electrochemiluminescent sensor based on the copper indium sulfur / carbohydrazide system as the working electrode and carbohydrazide as the co-reactant, measuring the cathode or anode electrochemiluminescent signal of the system in electrolyte solutions with known different pH values, and drawing a working curve according to the electrochemiluminescent signal corresponding to the pH value;

[0040] 2) The pH-type electrochemiluminescence sensor based on the copper indium sulfur / carbohydrazide system is used as the working electrode and carbohydrazide as the co-reactant, which is placed in the solution to be tested, and the cathode or anode electrochemiluminescence signal of the system is measured, and the pH value of the test solution is obtained according to the working curve.

[0041] Preferably according to the present invention, the electrolyte solution is a hydrochloric acid-tris buffer solution, a phosphate buffer solution or a carbonate buffer solution.

[0042] Preferably according to the present invention, the concentration of carbohydrazide in the system is 10-60 mM.

[0043] The technical features and advantages of the present invention are as follows:

[0044] 1. The present invention prepares core-shell structured copper indium sulfur nanocrystals by a one-pot method. The prepared copper indium sulfur nanocrystals have the advantages of being free of toxic elements, having good bioaffinity and being stable in storage.

[0045] 2. The pH-type electrochemiluminescent sensor based on the copper indium sulfur / carbohydrazine system of the present invention has a maximum wavelength of electrochemiluminescence of 743 nm in the near infrared under the condition of carbohydrazine co-reactant. Under different pH conditions, it shows obvious anode or cathode electrochemiluminescence signals, the anode electrochemiluminescence signal increases with the increase of pH value, and shows a linear correlation in the range of 5-12 pH of the electrolyte, and the cathode electrochemiluminescence signal decreases with the increase of pH value, and shows a linear correlation in the range of 1-4 pH of the electrolyte, and can quantitatively detect the pH value of the solution, with high accuracy, good reproducibility, strong stability, high sensitivity, simpler and more flexible operation, and low detection cost.

[0046] 3. The electrochemiluminescent radiation of the present invention can detect electrolytes with a pH value range of 1-12 in the anode and cathode ranges, respectively, with a strong linear correlation. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a normalized cathode electrochemiluminescence spectrum of the pH-type electrochemiluminescence sensor prepared in Example 1 under the condition of pH 1-4.

[0048] Figure 2 This is the cathode electrochemiluminescence intensity spectrum of the pH-type electrochemiluminescence sensor prepared in Example 1 under the condition of pH 1-4.

[0049] Figure 3 This is the cathode electrochemiluminescence intensity working curve of the pH-type electrochemiluminescence sensor prepared in Example 1 under the condition of pH 1-4.

[0050] Figure 4 This is a normalized anodic electrochemiluminescence spectrum of the pH-type electrochemiluminescence sensor prepared in Example 1 under the condition of pH 5-12.

[0051] Figure 5 This is the anode electrochemiluminescence intensity spectrum of the pH-type electrochemiluminescence sensor prepared in Example 1 under the condition of pH 5-12.

[0052] Figure 6 This is the anode electrochemiluminescence intensity working curve of the pH-type electrochemiluminescence sensor prepared in Example 1 under the condition of pH 5-12.

[0053] Figure 7The pH-type electrochemiluminescence sensor prepared in Example 1 uses tripropylamine as a coreactant and shows the electrochemiluminescence intensity working curve under different pH conditions. DETAILED DESCRIPTION

[0054] The present invention is further illustrated by the following examples, but is not limited thereto.

[0055] The fluorescence spectrum of the copper indium sulfide nanocrystals described in the embodiment was acquired by using a F-4700 fluorescence spectrophotometer.

[0056] The UV-visible absorption spectra were acquired by an Agilent Cary 60 UV-visible spectrophotometer.

[0057] The electrochemiluminescence spectrum was acquired by the GCFG-A electrochemiluminescence spectrum acquisition system developed by Shandong Guochen Biotechnology Co., Ltd. The potential window used was 0-1.6V, and the scanning speed was 50mV / s.

[0058] The electrochemiluminescence test used a glassy carbon electrode as the working electrode, an Ag / AgCl electrode as the reference electrode, and a Pt wire as the counter electrode. The copper indium sulfur modified electrode was prepared by drop-coating 10 μL of a 2 mg / mL copper indium sulfur solution on the surface of the working electrode and then air-drying. The test solution was a 0.1 mol / L phosphate buffer solution (pH 7.4) containing 50 mmol / L carbohydrazide. The collected electrochemiluminescence spectrum was the integrated spectrum of all electrochemiluminescence radiation.

[0059] Example 1

[0060] The preparation method of the pH type electrochemiluminescence sensor based on the copper indium sulfur / carbohydrazine system comprises the following steps:

[0061] (1) 900 μL of copper chloride solution (0.01 M), 40 μL of indium chloride solution (5.0 mM), 0.0062 g of glutathione solid powder and 400 μL of sodium citrate solution (0.4 M) were mixed into 20 ml of ultrapure water, stirred evenly in a 100 ml three-necked flask, and 62 μL of sodium sulfide solution (1.0 M) was injected, and the solution changed from colorless to dark yellow. The obtained solution was heated at 95° C. for 40 minutes to obtain a core-structured copper indium sulfur nanocrystal solution;

[0062] (2) 0.061 g of thiourea, 0.376 g of glutathione and 0.177 g of zinc acetate solution were mixed into 20 ml of ultrapure water to obtain a mixed solution, and 5 ml of the mixed solution was injected into the core-structured copper indium sulfur nanocrystal solution obtained in step (1), and the mixture was heated at 95° C. for 30 minutes; the mixture was then purified by centrifugation with isopropanol, and the obtained precipitate was the core-shell structured copper indium sulfur nanocrystal.

[0063] (4) Using core-shell structured copper indium sulfur nanocrystals as the luminescent material, 10 μL of a 2 mg / mL core-shell structured copper indium sulfur nanocrystal solution was dropped onto a glassy carbon electrode and allowed to dry at room temperature to obtain a pH-type electrochemiluminescence sensor.

[0064] Example 2

[0065] A method for quantitatively detecting the pH value of a solution using a pH-type electrochemiluminescence sensor based on a copper indium sulfur / carbohydrazine system, the steps are as follows:

[0066] 1) Using the working electrode of the pH-type electrochemiluminescent sensor based on the copper indium sulfur / carbohydrazide system of Example 1 and carbohydrazide as a co-reactant, the cathode or anode electrochemiluminescence signal of the system is measured in electrolyte solutions with known different pH values, and a working curve is drawn according to the electrochemiluminescence signal corresponding to the pH value;

[0067] 2) The working electrode of the pH-type electrochemiluminescent sensor based on the copper indium sulfur / carbohydrazide system of Example 1 is placed in a solution to be tested with carbohydrazide as a co-reactant, and the cathode or anode electrochemiluminescence signal of the system is measured, and the pH value of the test solution is obtained according to the working curve.

[0068] Under different pH conditions, it shows obvious anodic or cathodic electrochemiluminescence signals and presents a corresponding linear correlation, which can quantitatively detect the pH value of the solution.

[0069] Experimental Example 1

[0070] The pH-type electrochemiluminescence sensor of Example 1 was used as the working electrode, the Ag / AgCl electrode was used as the reference electrode, and the Pt wire was used as the counter electrode. The potential window used was 0-1.6 V, the scanning speed was 50 mV / s, and the test solution was a 0.1 M phosphate buffer solution containing 10 mM carbohydrazide. The electrochemiluminescence spectrum collected under different pH conditions was the integrated spectrum of all ECL radiation.

[0071] The normalized cathode electrochemiluminescence spectrum, cathode electrochemiluminescence intensity spectrum, and cathode electrochemiluminescence intensity working curve of the pH-type electrochemiluminescence sensor prepared in Example 1 under the conditions of pH 1-4 are shown in FIG. Figure 1-3 .

[0072] Figure 1-3 It can be seen that under different pH conditions, obvious cathode electrochemiluminescence signals are displayed. When carbohydrazide is used as a co-reactant, the maximum wavelength of its electrochemiluminescence is 743nm in the near infrared, and it is linearly correlated in the range of pH = 1-4 of the electrolyte solution. 2 The value is 0.992.

[0073] The normalized anodic electrochemiluminescence spectrum, anodic electrochemiluminescence intensity spectrum, and anodic electrochemiluminescence intensity working curve of the pH-type electrochemiluminescence sensor prepared in Example 1 under the condition of pH 5-12 are shown in FIG. Figure 4-6 .

[0074] Figure 4-6 It can be seen that under different pH conditions, obvious anodic electrochemiluminescence signals are displayed. When carbohydrazide is used as a co-reactant, the maximum wavelength of its electrochemiluminescence is 743nm in the near infrared, and it shows a linear correlation in the range of electrolyte pH 5-12. 2 The value is 0.996.

[0075] Comparative Example 1

[0076] The pH type electrochemiluminescence sensor of Example 1 was used as the working electrode, the Ag / AgCl electrode was used as the reference electrode, and the Pt wire was used as the counter electrode. The potential window used was 0-1.6 V, the scanning speed was 50 mV / s, and the conventional tripropylamine was used as the coreactant to replace the carbohydrazide of Experimental Example 1. The electrochemiluminescence intensity under different pH conditions was shown in FIG. Figure 7 ,pass Figure 7 It can be seen that the electrochemiluminescence intensity values ​​under different pH conditions are not linearly correlated, and the pH cannot be detected.

[0077] Example 3

[0078] The same preparation method as described in Example 1, except that:

[0079] In step (1), the concentration of the cupric chloride solution is 0.008 M, the concentration of the indium chloride solution is 4.5 mM, the concentration of the sodium citrate solution is 0.3 M, the concentration of the sodium sulfide solution is 0.8 M, and the rest is carried out as in Example 1.

[0080] Example 4

[0081] The same preparation method as described in Example 1, except that:

[0082] Step (2), 0.058 g of thiourea, 0.366 g of glutathione and 0.180 g of zinc acetate solution are mixed into 20 ml of ultrapure water to obtain a mixed solution, 5 ml of the mixed solution is injected into the core-structured copper indium sulfur nanocrystal solution obtained in step (1), and the mixture is heated at 95° C. for 30 minutes; the mixture is then purified by centrifugation with isopropanol, and the obtained precipitate is the core-shell structured copper indium sulfur nanocrystal. The rest is carried out as in Example 1.

Claims

1. A method for preparing a pH-type electrochemiluminescent sensor based on a copper indium sulfur / carbohydrazine system, comprising the following steps: (1) mixing a copper chloride solution, an indium chloride solution, a glutathione solid powder and a sodium citrate solution into ultrapure water and stirring the mixture to obtain a mixed solution a; Sodium sulfide solution is injected, and the solution changes from colorless to dark yellow. The obtained solution is heated to react to obtain a core structure copper indium sulfur nanocrystal solution; (2) mixing thiourea, glutathione and zinc acetate solution into ultrapure water to obtain a mixed solution b, injecting the mixed solution b into the core structure copper indium sulfur nanocrystal solution obtained in step (1), and heating for reaction; (3) After heating the reaction, purifying with isopropanol, the resulting precipitate is a core-shell structured copper indium sulfur nanocrystal; (4) Using the core-shell structured copper indium sulfur nanocrystals purified in step (3) as the luminescent material, placing the indium sulfur core-shell structured nanocrystals on a glassy carbon electrode and drying at room temperature to prepare a pH-type electrochemiluminescence sensor.

2. The preparation method according to claim 1, characterized in that: In step (1), the concentration of the cupric chloride solution is 0.005-0.02M, the concentration of the indium chloride solution is 4.0-6.0mM, the concentration of the sodium citrate solution is 0.2-0.6M, and the concentration of the sodium sulfide solution is 0.5-2M.

3. The preparation method according to claim 1, characterized in that: In step (1), the molar ratio of copper chloride: indium chloride: glutathione: sodium sulfide is (40-50):1:(700-900):(270-470).

4. The preparation method according to claim 1, characterized in that: In step (1), the molar ratio of indium chloride to sodium citrate is 1:(0.6-20), the volume ratio of cupric chloride solution to ultrapure water is (0.5-2):(10-30), and the heating reaction is carried out at 90-100° C. for 30-60 minutes.

5. The preparation method according to claim 1, characterized in that: In step (2), the molar ratio of thiourea: zinc acetate: glutathione is (5-15): (8-12): (8-25).

6. The preparation method according to claim 1, characterized in that: In step (2), the mass volume ratio of thiourea to ultrapure water is (0.01-0.1):(10-30), unit, g / mL, the volume ratio of the mixed solution b to the core structure copper indium sulfur nanocrystal solution is 1:(3-6), and the heating reaction is carried out at 90-100° C. for 20-40 minutes.

7. The preparation method according to claim 1, characterized in that: In step (3), the isopropanol purification is performed by adding isopropanol to the solution of step (2) and centrifuging at 13300 rpm. In step (4), the concentration of the core-shell structured copper indium sulfur nanocrystals is 0.5-3 mg / mL. In step (4), the amount of the core-shell structured copper indium sulfur nanocrystals used is 9-11 μL.

8. A pH-type electrochemiluminescence sensor based on a copper indium sulfide / carbohydrazine system, constructed using the method described in claims 1-7.

9. Use of the pH-type electrochemiluminescence sensor based on the copper indium sulfur / carbohydrazine system according to claim 8 for quantitatively detecting the pH value of a solution.

10. The use according to claim 9, characterized in that: The method for quantitatively detecting the pH value of a solution using a pH-type electrochemiluminescence sensor based on a copper indium sulfur / carbohydrazine system comprises the following steps: 1) Using the above-mentioned pH-type electrochemiluminescent sensor based on the copper indium sulfur / carbohydrazide system as the working electrode and carbohydrazide as the co-reactant, measuring the cathode or anode electrochemiluminescent signal of the system in electrolyte solutions with known different pH values, and drawing a working curve according to the electrochemiluminescent signal corresponding to the pH value; 2) The pH electrochemiluminescence sensor based on the copper indium sulfur / carbohydrazide system is used as the working electrode and carbohydrazide is used as the co-reactant, and is placed in the solution to be tested, and the cathode or anode electrochemiluminescence signal of the system is measured, and the pH value of the test solution is obtained according to the working curve. The electrolyte solution is a hydrochloric acid-tris buffer solution, a phosphate buffer solution or a carbonate buffer solution, and the concentration of carbohydrazide in the system is 10-60 mM.

Images