Glucose sensor based on flaky nanometer nickel hydroxide

Abstract

The application discloses a sheet-shaped nanometer nickel hydroxide glucose sensor based on glucose detection technology, and comprises the following steps: (1) obtaining a deep blue hexammine nickel complex; (2) adjusting the temperature and keeping stirring; (3) obtaining a light green paste; (4) obtaining a green powder s-Ni(OH)2 nanoparticle; (5) obtaining treated graphene; (6) obtaining composite graphene particles; (7) obtaining a composite dispersion liquid; (8) obtaining a coating liquid; (9) coating the coating liquid on the surface of an electrode, and drying, and the application is completed; the application provides the sheet-shaped nanometer nickel hydroxide glucose sensor, the electrode which is co-modified by the sheet-shaped nickel hydroxide and the composite graphene particles has better catalytic performance, and the detection performance of the glucose sensor is greatly improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of glucose detection, and particularly relates to a glucose sensor based on sheet-shaped nanometer nickel hydroxide. BACKGROUND

[0002] In modern society, diabetes has become a very common disease, and the incidence also shows a rising trend year by year. It is of great significance to develop a high-sensitivity, attachable, flexible and transparent glucose sensor for the study of metabolism of organisms and diagnosis of diabetes.

[0003] At present, diabetes, as one of the four major non-communicable diseases, has become an increasingly serious global public health problem. Diabetic patients need to check the glucose content in the blood frequently to avoid various fatal emergencies caused by hyperglycemia, and therefore, it is extremely important to accurately and quickly analyze the glucose content in the blood. The concentration of glucose is one of the important indicators for diagnosing and treating diabetes, and current glucose sensors include enzyme-type glucose sensors and enzyme-free glucose sensors.

[0004] In the existing glucose detection method, a glucose oxidase (GOx) film is mostly used. However, some weaknesses of the enzyme itself are difficult to overcome, such as the activity of GOx being easily affected by temperature, humidity and pH, and the enzyme being poisoned and disabled by toxic chemicals. The enzyme-free sensor overcomes the harsh environmental requirements of the enzyme sensor, and therefore, the enzyme-free glucose sensor has become a new trend in the development of blood glucose meters.

[0005] Reports on the application of nickel nanoparticles in enzyme-free glucose biosensors show that nickel nanoparticles have great improvement in electrocatalytic oxidation of glucose compared with other metal nanoparticles, but the elemental nickel nanoparticles are unstable and are easily oxidized in air and solution.

[0006] Therefore, it is necessary to further improve the prior art. SUMMARY

[0007] The purpose of the present application is to provide a glucose sensor based on sheet-shaped nanometer nickel hydroxide to solve the problems in the prior art.

[0008] The technical scheme adopted by the present application is as follows:

[0009] The glucose sensor based on sheet-shaped nanometer nickel hydroxide comprises the following steps:

[0010] (1) Using nickel nitrate as a nickel source, a precipitating agent is slowly added into a nickel nitrate solution in a reaction kettle, and stirring is performed to obtain a deep blue hexammine nickel complex;

[0011] The concentration of the nickel nitrate solution is 1 mol / L;

[0012] (2) Continue to adjust the temperature in the reaction kettle to 70-75℃, and keep stirring for 1 hour;

[0013] (3) Filter off the excess reaction liquid to obtain a light green precipitate, and wash it with anhydrous ethanol and ultrapure water alternately for 3 times to obtain a light green paste;

[0014] (4) Dry the light green paste in a vacuum oven at a drying temperature of 70-80℃ for 10-12 hours, and finally obtain the product as green powder s-Ni(OH)2nanoparticles.

[0015] (5) Add graphene to the acid treatment solution, stir for 30 min, filter, and wash with water until neutral to obtain treated graphene;

[0016] (6) Disperse the treated graphene uniformly in acetaldehyde to obtain a dispersion liquid, add silver amine solution dropwise to the dispersion liquid, stir for 30-40 min, then filter, wash, and dry to obtain composite graphene particles;

[0017] (7) Disperse the s-Ni(OH)2nanoparticles and the composite graphene particles uniformly in ethanol to obtain a composite dispersion liquid;

[0018] (8) Add the composite dispersion liquid to a nafion solution to obtain a coating liquid;

[0019] (9) Coat the coating liquid on the surface of the electrode, and dry it.

[0020] As a further technical solution: the precipitant in step (1) is ammonia water;

[0021] The mass fraction of the ammonia water is 28-30wt%;

[0022] The volume ratio of the mixture of ammonia water and nickel nitrate solution is 1:1-1.2.

[0023] As a further technical solution: the mixing mass ratio of graphene and acid treatment solution in step (5) is 1:20-25;

[0024] The stirring temperature is 70℃.

[0025] As a further technical solution: the acid treatment solution is a mixture of nitric acid solution and sulfuric acid solution;

[0026] The concentration of nitric acid is 1-1.5mol / L;

[0027] The concentration of sulfuric acid is 3-4mol / L.

[0028] As a further technical solution: the mixing mass ratio of the dispersion liquid in step (6) and the silver ammonia solution is 1:1.2-1.6.

[0029] The silver ion concentration in the silver ammonia solution is 0.11 mol / L.

[0030] As a further technical solution: the mixing ratio of the s-Ni(OH)2 nanoparticles in step (7) and the composite graphene particles, ethanol is 3-5g:1g:50mL.

[0031] As a further technical solution: the mixing mass ratio of the composite dispersion liquid and the nafion solution in step (8) is 1:15-20.

[0032] As a further technical solution: the nafion solution adopts a mass fraction of 5% nafion solution.

[0033] As a further technical solution: the coating amount of the coating liquid in step (9) coated on the electrode is 0.3-0.5g / cm 2 .

[0034] As a further technical solution: the electrode in step (9) adopts a glassy carbon electrode.

[0035] The sheet-shaped nanometer nickel hydroxide is used as the electrode modification material of the enzyme-free glucose sensor, which can greatly improve the electrochemical performance of the electrode, and the sensitivity of the prepared enzyme-free glucose sensor is further improved. Meanwhile, the sheet-shaped nanometer nickel hydroxide is combined with the composite graphene particles, and the sensitivity and response efficiency of the enzyme-free glucose sensor are further improved, and the stability is higher and the storage is longer.

[0036] In the enzyme-free electrochemical glucose sensor, the main principle of the sheet-shaped nanometer nickel hydroxide is that Ni(OH)2 is oxidized to NiOOH in an alkaline environment, so that the oxidation peak

[0037] Ni(OH)2+OH - →NiOOH+H2O;

[0038] When the glucose (Glu) is added, due to the catalytic effect of Ni 3+ , the glucose is oxidized to glucose lactone C6H 10 O6, and the current value of the oxidation peak is greatly improved:

[0039] 2NiOOH+C6H 12 O6→2Ni(OH)2+C6H 10 O6.

[0040] Beneficial effects:

[0041] The application provides a flaky nanometer nickel hydroxide glucose sensor, and the electrode co-modified by the flaky nickel hydroxide and the composite graphene particles has better catalytic performance, so that the detection performance of the glucose sensor is greatly improved, which may be due to the fact that the structure cooperation of the flaky nickel hydroxide and the composite graphene particles increases the specific surface area of the electrode, and meanwhile, the electrochemical active surface sites are increased, so that the sensing performance of the sensor is improved. On the other hand, the current response of the flaky nickel hydroxide and the composite graphene particles to glucose is significantly improved, because the flaky nickel hydroxide and the composite graphene particles can promote the transfer of electrons in the solution, and can further promote the electrocatalytic oxidation reaction of the electrode to glucose, so that the detection performance of the sensor is improved as a whole. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 is a standard curve diagram of anode current density corresponding to different scanning rates. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0044] Embodiment 1

[0045] The flaky nanometer nickel hydroxide glucose sensor comprises the following steps:

[0046] (1) taking nickel nitrate as a nickel source, slowly adding ammonia water into the nickel nitrate solution in a reaction kettle, and stirring to obtain a deep blue hexammine nickel complex;

[0047] The concentration of the nickel nitrate solution is 1 mol / L; and the mass fraction of the ammonia water is 28 wt%.

[0048] The volume ratio of the ammonia water to the nickel nitrate solution is 1:1.

[0049] (2) the temperature in the reaction kettle is continuously adjusted to 70 DEG C, and stirring is maintained for 1 hour;

[0050] (3) the excess reaction liquid is suction filtered to obtain a light green precipitate, and the light green precipitate is washed with anhydrous ethanol and ultrapure water alternately for three times to obtain a light green paste;

[0051] (4) the light green paste is dried in a vacuum oven, the drying temperature is 70 DEG C, and the drying time is 10 hours, and finally the product is a green powder s-Ni(OH)2nanoparticle.

[0052] (5) adding graphene into acid treatment solution, stirring for 30 min, suction filtration, washing with water until neutral, to obtain treated graphene; the mixing mass ratio of graphene and acid treatment solution is 1:20;

[0053] The stirring treatment temperature is 70℃.

[0054] The acid treatment solution is mixed by nitric acid solution and sulfuric acid solution;

[0055] The concentration of nitric acid is 1mol / L;

[0056] The concentration of sulfuric acid is 3mol / L.

[0057] (6) uniformly dispersing treated graphene into acetaldehyde to obtain a dispersion liquid, adding silver amine solution dropwise into the dispersion liquid, stirring for 30 min, then suction filtration, washing and drying to obtain composite graphene particles; the mixing mass ratio of the dispersion liquid and silver amine solution is 1:1.2;

[0058] The concentration of silver ion in the silver amine solution is 0.11mol / L.

[0059] (7) uniformly dispersing s-Ni(OH)2 nanoparticles and composite graphene particles into ethanol to obtain a composite dispersion liquid; the mixing ratio of s-Ni(OH)2 nanoparticles, composite graphene particles and ethanol is 3g:1g:50mL.

[0060] (8) adding the composite dispersion liquid into nafion solution to obtain a coating liquid; the mixing mass ratio of the composite dispersion liquid and nafion solution is 1:15.

[0061] The nafion solution is 5wt% nafion solution.

[0062] (9) coating the coating liquid onto the surface of the electrode, and drying, to obtain the electrode; the coating amount of the coating liquid on the electrode is 0.3g / cm 2 ; the electrode is a glassy carbon electrode.

[0063] Example 2

[0064] The sheet-shaped nanometer nickel hydroxide glucose sensor comprises the following steps:

[0065] (1) taking nickel nitrate as a nickel source, slowly adding ammonia water into the nickel nitrate solution in a reaction kettle, and stirring to obtain a deep blue hexammine nickel complex;

[0066] The concentration of the nickel nitrate solution is 1mol / L; the mass fraction of the ammonia water is 28.5wt%;

[0067] The volume ratio of the ammonia water to the nickel nitrate solution is 1:1.1.

[0068] (2) Continue to adjust the temperature in the reaction kettle to 72℃, and keep stirring for 1 hour;

[0069] (3) Filter off the excess reaction liquid to obtain a light green precipitate, and wash the precipitate with anhydrous ethanol and ultrapure water alternately for 3 times to obtain a light green paste;

[0070] (4) Dry the light green paste in a vacuum oven at a drying temperature of 75℃ for 11 hours, and finally obtain a green powder s-Ni(OH)2nanoparticle.

[0071] (5) Add the graphene to the acid treatment solution, stir for 30 min, filter, and wash with water until neutral to obtain treated graphene; the mixing mass ratio of the graphene to the acid treatment solution is 1:22;

[0072] The stirring temperature is 70℃.

[0073] The acid treatment solution is obtained by mixing a nitric acid solution and a sulfuric acid solution;

[0074] The concentration of the nitric acid is 1.2 mol / L;

[0075] The concentration of the sulfuric acid is 3.5 mol / L.

[0076] (6) Disperse the treated graphene uniformly in acetaldehyde to obtain a dispersion liquid, add silver amine solution dropwise into the dispersion liquid, stir for 35 min, then filter, wash, and dry to obtain composite graphene particles; the mixing mass ratio of the dispersion liquid to the silver amine solution is 1:1.4;

[0077] The concentration of silver ions in the silver amine solution is 0.11 mol / L.

[0078] (7) Disperse the s-Ni(OH)2nanoparticles and the composite graphene particles uniformly in ethanol to obtain a composite dispersion liquid; the mixing ratio of the s-Ni(OH)2nanoparticles, the composite graphene particles, and ethanol is 3.5 g:1 g:50 mL.

[0079] (8) Add the composite dispersion liquid into a nafion solution to obtain a coating liquid; the mixing mass ratio of the composite dispersion liquid to the nafion solution is 1:16.

[0080] The nafion solution is a 5% nafion solution.

[0081] (9) Coating the coating liquid on the surface of the electrode, and dry it; the coating amount of the coating liquid on the electrode is 0.35 g / cm 2The electrode is a glassy carbon electrode.

[0082] Example 3

[0083] The glucose sensor based on flaky nanometer nickel hydroxide includes the following steps:

[0084] (1) Using nickel nitrate as the nickel source, ammonia water is slowly added into the nickel nitrate solution in a reaction kettle, and stirring is performed to obtain a deep blue hexammine nickel complex;

[0085] The concentration of the nickel nitrate solution is 1 mol / L; the mass fraction of the ammonia water is 29 wt%.

[0086] The volume ratio of the ammonia water to the nickel nitrate solution is 1:1.2.

[0087] (2) The temperature in the reaction kettle is continuously adjusted to 73°C, and stirring is maintained for 1 hour;

[0088] (3) The excess reaction liquid is suction-filtered to obtain a light green precipitate, which is washed with anhydrous ethanol and ultrapure water alternately for 3 times to obtain a light green paste;

[0089] (4) The light green paste is dried in a vacuum oven at a drying temperature of 76°C for 11 hours, and the final product is a green powder s-Ni(OH)2nanoparticles.

[0090] (5) Graphene is added into an acid treatment solution, stirring is performed for 30 min, suction filtration is performed, and washing with water is performed until neutralization to obtain treated graphene; the mixing mass ratio of the graphene to the acid treatment solution is 1:24;

[0091] The stirring treatment temperature is 70°C.

[0092] The acid treatment solution is obtained by mixing a nitric acid solution and a sulfuric acid solution;

[0093] The concentration of the nitric acid is 1.2 mol / L.

[0094] The concentration of the sulfuric acid is 3.6 mol / L.

[0095] (6) The treated graphene is uniformly dispersed into acetaldehyde to obtain a dispersion liquid, silver amine solution is added dropwise into the dispersion liquid, stirring is performed for 35 min, and then suction filtration, washing, and drying are performed to obtain composite graphene particles; the mixing mass ratio of the dispersion liquid to the silver amine solution is 1:1.5;

[0096] The concentration of silver ions in the silver amine solution is 0.11 mol / L.

[0097] (7) The s-Ni(OH)2 nanoparticles and composite graphene particles were uniformly dispersed in ethanol to obtain a composite dispersion; the mixing ratio of s-Ni(OH)2 nanoparticles, composite graphene particles and ethanol was 4g:1g:50mL.

[0098] (8) Add the composite dispersion to the Nafion solution to obtain the coating solution; the mass ratio of the composite dispersion to the Nafion solution is 1:18.

[0099] The Nafion solution used was a 5% Nafion solution.

[0100] (9) Apply the coating solution to the electrode surface and allow it to dry; the coating amount of the coating solution applied to the electrode is 0.4 g / cm³. 2 The electrode is a glassy carbon electrode.

[0101] Example 4

[0102] The glucose sensor based on sheet-like nano-nickel hydroxide includes the following steps:

[0103] (1) Using nickel nitrate as the nickel source, ammonia water was slowly added to the nickel nitrate solution in the reaction vessel and stirred to obtain a dark blue hexaammine nickel complex.

[0104] The nickel nitrate solution has a concentration of 1 mol / L; the ammonia solution has a mass fraction of 30 wt%.

[0105] The volume ratio of ammonia water to nickel nitrate solution is 1:1.2.

[0106] (2) Continue to adjust the temperature inside the reactor to 75°C and keep stirring for 1 hour;

[0107] (3) Filter off the excess reaction liquid and obtain a light green precipitate. Wash the precipitate three times with anhydrous ethanol and ultrapure water respectively to obtain a light green paste.

[0108] (4) The light green paste was dried in a vacuum oven at 80°C for 12 hours. The final product was green powder s-Ni(OH)2 nanoparticles.

[0109] (5) Add graphene to the acid treatment solution, stir for 30 min, filter, and wash with water until neutral to obtain treated graphene; the mass ratio of graphene to acid treatment solution is 1:25.

[0110] The stirring temperature is 70℃.

[0111] The acid treatment solution is a mixture of nitric acid solution and sulfuric acid solution;

[0112] The concentration of nitric acid is 1.5 mol / L.

[0113] The sulfuric acid concentration is 4 mol / L.

[0114] (6) The treated graphene was uniformly dispersed in acetaldehyde to obtain a dispersion. Silver ammonia solution was added dropwise to the dispersion and the mixture was stirred for 40 min. Then, the mixture was filtered, washed, and dried to obtain composite graphene particles. The mass ratio of the dispersion to the silver ammonia solution was 1:1.6.

[0115] The concentration of silver ions in the silver ammonia solution is 0.11 mol / L.

[0116] (7) The s-Ni(OH)2 nanoparticles and composite graphene particles were uniformly dispersed in ethanol to obtain a composite dispersion; the mixing ratio of s-Ni(OH)2 nanoparticles, composite graphene particles and ethanol was 5g:1g:50mL.

[0117] (8) Add the composite dispersion to the Nafion solution to obtain the coating solution; the mass ratio of the composite dispersion to the Nafion solution is 1:20.

[0118] The Nafion solution used was a 5% Nafion solution.

[0119] (9) Apply the coating solution to the electrode surface and allow it to dry; the coating amount of the coating solution applied to the electrode is 0.5 g / cm³. 2 The electrode is a glassy carbon electrode.

[0120] Comparative Example 1:

[0121] Based on Example 1, step (7) is adjusted so that no composite graphene particles are added, while the rest of the technical solutions in Example 1 are the same.

[0122] Comparative Example 2:

[0123] Based on Example 1, the composite graphene particles were replaced with an equal amount of graphene, while the rest of the technical solutions were the same as in Example 1.

[0124] test

[0125] Cyclic voltammetry was used to detect glucose concentration under alkaline conditions. The examples and comparative samples were applied to the detection of glucose concentrations from 400 nM to 4 mM using a current-time method. The detection sensitivities are shown in Table 1.

[0126] Table 1

[0127] μA·cm -2 ·mM -1 ]]> Example 1 2670.513 Example 2 2816.524 Example 3 2733.406 Example 4 2758.173 Comparative Example 1 2312.762 Comparative Example 2 2552.118

[0128] As can be seen from Table 1, the sensor prepared by the present invention has high sensitivity for glucose detection and can meet the daily blood glucose detection needs.

[0129] Electrochemical tests were conducted using a three-electrode system. Examples and comparative samples were tested using a sensor with platinum wire and silver / silver chloride (Ag / AgCl) as the auxiliary and reference electrodes, respectively. A 0.2 mol / L sodium hydroxide solution was used as the electrolyte. The electrochemical performance of the example and comparative samples was tested. At a working voltage of 0.45 V, 0.5 mmol / L glucose solution was added to a continuously stirred 0.2 mol / L sodium hydroxide solution, and the response current was measured.

[0130] Table 2

[0131] Response current A Example 1 0.42 Example 2 0.43 Example 3 0.46 Example 4 0.44 Comparative Example 1 0.25 Comparative Example 2 0.32

[0132] As can be seen from Table 2, the sensor of the present invention has a high response current.

[0133] The experiment continued, using Example 1 as the base sample, to compare the effect of different coating amounts applied to the electrode on the response current:

[0134] Table 3

[0135] Coating amount g / cm 2 ]] Response current A 0.1 0.33 0.2 0.37 0.3 0.42 0.4 0.46 0.5 0.44 0.6 0.40

[0136] As can be seen from Table 3, with the increase of coating liquid amount, the response current first increases and then decreases slightly.

[0137] Using Example 1 as the base sample, the effects of different coating amounts applied to the electrode with different coating solutions on the response current were compared. Figure 1 .

[0138] The above description is only a preferred embodiment of the present invention, but the present invention is not limited to the scope of implementation shown. Any changes made in accordance with the concept of the present invention, or equivalent embodiments modified to have equivalent changes, shall be within the protection scope of the present invention as long as they do not exceed the spirit covered by the specification.

Claims

1. A glucose sensor based on sheet-like nano-nickel hydroxide, characterized in that: Includes the following steps: (1) Using nickel nitrate as the nickel source, the precipitant was slowly added to the nickel nitrate solution in the reaction vessel and stirred to obtain a dark blue hexaammine nickel complex; The concentration of the nickel nitrate solution was 1 mol / L; (2) Continue to adjust the temperature inside the reactor to 70-75℃ and keep stirring for 1 hour; (3) Filter off the excess reaction liquid, and the resulting light green precipitate is washed three times with anhydrous ethanol and ultrapure water respectively to obtain a light green paste. (4) The light green paste was dried in a vacuum oven at a temperature of 70-80℃ for 10-12 hours. The final product was green powder s-Ni(OH)2 nanoparticles. (5) Add graphene to the acid treatment solution, stir for 30 min, filter, and wash with water until neutral to obtain treated graphene. The acid treatment solution is a mixture of nitric acid solution and sulfuric acid solution; The concentration of nitric acid is 1-1.5 mol / L; The sulfuric acid concentration is 3-4 mol / L; (6) The treated graphene is uniformly dispersed in acetaldehyde to obtain a dispersion. Silver ammonia solution is added dropwise to the dispersion and the mixture is stirred for 30-40 min. Then, the mixture is filtered, washed, and dried to obtain composite graphene particles. (7) The s-Ni(OH)2 nanoparticles and composite graphene particles were uniformly dispersed in ethanol to obtain a composite dispersion; (8) Add the composite dispersion to the Nafion solution to obtain the coating solution; (9) Apply the coating solution to the electrode surface and let it dry.

2. The glucose sensor based on sheet-like nano-nickel hydroxide according to claim 1, characterized in that: The precipitant mentioned in step (1) is ammonia; The ammonia solution has a mass fraction of 28-30 wt%. The volume ratio of ammonia water to nickel nitrate solution is 1:1-1.

2.

3. The glucose sensor based on sheet-like nano-nickel hydroxide according to claim 1, characterized in that: The mass ratio of graphene to acid treatment solution in step (5) is 1:20-25; The stirring temperature is 70℃.

4. The glucose sensor based on sheet-like nano-nickel hydroxide according to claim 1, characterized in that: In step (6), the mass ratio of the dispersion to the silver ammonia solution is 1:1.2-1.

6. The concentration of silver ions in the silver ammonia solution is 0.11 mol / L.

5. The glucose sensor based on sheet-like nano-nickel hydroxide according to claim 1, characterized in that: In step (7), the mixing ratio of s-Ni(OH)2 nanoparticles, composite graphene particles, and ethanol is 3-5g:1g:50mL.

6. The glucose sensor based on sheet-like nano-nickel hydroxide according to claim 1, characterized in that: The mass ratio of the composite dispersion and the Nafion solution in step (8) is 1:15-20.

7. The glucose sensor based on sheet-like nano-nickel hydroxide according to claim 6, characterized in that: The Nafion solution used is a 5% Nafion solution by mass.

8. The glucose sensor based on sheet-like nano-nickel hydroxide according to claim 1, characterized in that: The amount of coating solution applied to the electrode in step (9) is 0.3-0.5 g / cm².

9. The glucose sensor based on sheet-like nano-nickel hydroxide according to claim 1, characterized in that: The electrode used in step (9) is a glassy carbon electrode.

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