A method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials and its application

Abstract

The invention discloses a method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials and its application, belonging to the field of colorimetric sensing technology. The method comprises first preparing a core-shell structured MnCo@C NCs active material, utilizing its high catalytic activity, adding MnCo@C NCs to a plurality of morpholineethanesulfonic acid buffer samples containing catecholamines at different concentrations, reacting, recording the absorbance value A of each sample at a wavelength of 485nm after the reaction, and obtaining a detection linear relationship between the catecholamine concentration and the absorbance value A. According to the detection linear relationship and the absorbance value of the sample to be tested containing catecholamines, the concentration of catecholamines in the sample to be tested is analyzed. The colorimetric detection method has the advantages of low cost, simple operation, rapid response, high sensitivity, etc., and can be applied to human health diagnosis.

Description

Technical Field

[0001] The invention belongs to the technical field of colorimetric sensing, and relates to a colorimetric analysis method of catecholamines, and specifically to a method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials and an application of the method in human health diagnosis. Background Art

[0002] Catecholamines are a class of biogenic compounds, including dopamine, epinephrine and norepinephrine. They play important physiological roles in the human body as neurotransmitters and hormones, and are also important markers for diagnosing diseases and functional disorders, such as Parkinson's disease, schizophrenia and Alzheimer's disease. Therefore, the determination of catecholamines in the human body is of great significance for the diagnosis of diseases and the study of pathological and physiological mechanisms. At present, the methods for determining them include: high performance liquid chromatography, liquid chromatography-mass spectrometry, non-destructive imaging technology, etc. These methods have problems such as cumbersome instrument operation, complex pretreatment, high detection cost or long detection cycle. Therefore, it is urgent to develop a low-cost, simple, fast and highly sensitive method to quantitatively analyze phenolic pollutants in the environment.

[0003] Colorimetric analysis based on nanomaterials has attracted widespread attention due to its simplicity, cost-effectiveness, visualization, and field application. In particular, nanomaterials have been used in the field of colorimetric sensing due to their low cost, simple preparation, high stability, and excellent catalytic performance, which can catalyze the oxidation of catecholamines and produce visible color reactions. However, obtaining nanomaterials with high catalytic activity remains a challenge, which greatly limits their widespread application. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a low-cost, easy-to-operate, visual and highly sensitive method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials. The method has the advantages of low required reagent volume, rapid response, strong anti-interference ability, etc., and can be applied to human health diagnosis.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions.

[0006] A method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials, wherein the MnCo@C NCs is a core-shell structure, the core is a MnCo bimetallic oxide, and the shell is a porous carbon shell C NCs, and the method comprises the following steps:

[0007] (1) Preparation of MnCo@C NCs:

[0008] (1.1) dispersing manganese acetate and PVP in a mixed solution of ethanol and water and stirring, then adding a potassium cobalt cyanide aqueous solution and incubating at room temperature to obtain a MnCo precursor;

[0009] (1.2) Redispersing the MnCo precursor into an aqueous solution, then adding a dopamine aqueous solution and reacting at room temperature to obtain a polydopamine-coated MnCo precursor;

[0010] (1.3) pyrolyzing the polydopamine-coated MnCo precursor obtained above at high temperature to obtain a core-shell structured MnCo bimetallic oxide porous carbon active material, namely, MnCo@C NCs;

[0011] (2) adding the MnCo@C NCs prepared above to a plurality of morpholineethanesulfonic acid buffer samples containing different concentrations of catecholamines to obtain a mixed system, recording the absorbance value A of each sample at a wavelength of 485 nm after the reaction, and obtaining the detection linear relationship between the catecholamine concentration and the absorbance value A;

[0012] (3) The concentration of catecholamines in the sample to be tested is obtained based on the detection linear relationship between the catecholamine concentration and the absorbance value A obtained above and the absorbance value of the sample to be tested containing catecholamines.

[0013] In the method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials, preferably, in step (2), when MnCo@C NCs are added to a morpholineethanesulfonic acid buffer solution that does not contain catecholamines, the reaction system is almost colorless. When a sample containing catecholamines is added, a color reaction occurs in the reaction system, thereby qualitatively detecting whether the sample contains catecholamines.

[0014] In the above method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials, preferably, the catecholamines include epinephrine (EP). The linear regression equation for the detection of EP concentration and absorbance value A is:

[0015] When the concentration of 2,4-DP is 0.54μM~109.2μM, A=0.0035C EP +0.0153(1);

[0016] When the concentration of 2,4-DP is 109.2μM~272.9μM, A=0.0005C EP +0.33(2);

[0017] In formula (1) and (2), A represents the absorbance value, C EP is the concentration of adrenaline in the test solution, the unit of which is μM. The correlation coefficient R of formula (1) 2=0.991, the correlation coefficient R of formula (2) 2 =0.994, the detection linear range of adrenaline is 0.54μM~272.9μM, and the detection limit is 0.68μM.

[0018] Preferably, in step (1.1), the mass ratio of manganese acetate to PVP is 1:5-10, and the molar ratio of Mn to Co is 1:1-3.

[0019] Preferably, in step (1.2), the mass ratio of dopamine to MnCo precursor is 1:1-3.

[0020] Preferably, in step (2), the reaction time is 3 min to 10 min. In steps (2) and (3), the concentration of morpholineethanesulfonic acid is 30 mM to 50 mM.

[0021] As a general technical concept, the present invention also provides an application of the above-mentioned method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials in human health diagnosis and medical materials.

[0022] It should be noted that, in the present invention, the unit M refers to mol / L.

[0023] In the present invention, the concentrations of manganese acetate, PVP and potassium cobalt cyanide in water are not limited, and they can be dissolved in water.

[0024] The detection principle of the present invention is mainly that the MnCo@C NCs prepared by the present invention exhibit excellent catalytic activity, and can catalyze the oxidation of adrenaline and develop color in the presence of adrenaline under air conditions, and the solution becomes yellow-brown visible to the naked eye, and the color becomes darker as the concentration of adrenaline increases, which is reflected in the increase of the absorbance value at 485nm. Based on the strategy of catalyzing the oxidation of adrenaline and developing color, the detection of adrenaline is achieved.

[0025] Compared with the prior art, the advantages of the present invention are:

[0026] The present invention provides a method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials. After pyrolysis, the morphology of the MnCo precursor coated with polydopamine is characterized by a regular cubic structure. This unique structure provides MnCo@C NCs with a larger specific surface area and catalytic active sites. The material preparation method has the advantages of simple preparation process, low cost, high stability, environmental friendliness, etc., and is suitable for large-scale preparation. At the same time, the synergistic effect of Mn and Co and the reversible multivalent state give it high catalytic activity, and catecholamines can be catalytically oxidized and colored to generate red products under air conditions, thereby improving the detection sensitivity. In the reaction system, no other color developer is required, and only MnCo@C NCs can be added to catalyze the color development of the substrate, and the catalyst content is extremely low, and only at the μg / mL level can it be efficiently catalyzed, greatly reducing the detection cost. At the same time, the response is rapid, and the color change visible to the naked eye can be observed within 3 minutes by the colorimetric analysis method, greatly shortening the detection time.

[0027] The colorimetric sensing strategy of the present invention is based on catalyzing the oxidation of catecholamines to develop color, and has the advantages of simple operation, low cost, visualization and on-site application. By adding catecholamines of different concentrations to the colorimetric sensing system, a detection linear relationship between catecholamine concentration and absorbance value is established, and the concentration of catecholamines in the sample to be tested is calculated according to the detection linear regression equation. Rapid detection of catecholamines in human body fluids (such as blood and urine) can be achieved, and the method has good use value and market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a scanning electron microscope image of the MnCo@C NCs prepared in Example 1 of the present invention.

[0029] Figure 2 UV-vis graph of MnCo@C NCs prepared in Example 1 of the present invention catalyzing different concentrations of adrenaline.

[0030] Figure 3 This is a linear regression diagram of the detection of different concentrations of adrenaline and absorbance values ​​in Example 1 of the present invention.

[0031] Figure 4 This is to evaluate the anti-interference ability of MnCo@C NCs in detecting adrenaline in Example 1 of the present invention. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby. In the following embodiments, unless otherwise specified, the raw materials and instruments used are commercially available.

[0033] Example 1

[0034] The method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials comprises the following steps:

[0035] (1) Preparation of MnCo@C NCs:

[0036] (1.1) manganese acetate and PVP are dispersed in a mixed solution of ethanol and water and stirred, and then a potassium cobalt cyanide aqueous solution is added, the mass ratio of manganese acetate to PVP is 1:6, and the molar ratio of Mn to Co element is 1:1, and incubated at room temperature to obtain a MnCo precursor;

[0037] (1.2) redispersing the prepared MnCo precursor into an aqueous solution, and then adding a dopamine aqueous solution, wherein the mass ratio of dopamine to the MnCo precursor is 1:1, to obtain a polydopamine-coated MnCo precursor;

[0038] (1.3) The polydopamine-coated MnCo precursor obtained in step (1.2) is pyrolyzed at high temperature to obtain MnCo@CNCs nanomaterials. Figure 1 As shown in Figure 1, the MnCo@C NCs were analyzed by electron microscopy, and the results showed that the MnCo@C NCs had a regular hollow structure with a diameter of about 150 nm. The unique hollow structure would increase its specific surface area and provide more active sites. This shows that the hollow structure of MnCo@C NCs was successfully prepared.

[0039] (3) MnCo@C NCs were added into multiple 30 mM morpholineethanesulfonic acid buffers containing different concentrations of adrenaline, the concentrations of adrenaline were 0.54 μM, 1.09 μM, 2.73 μM, 5.46 μM, 16.38 μM, 27.23 μM, 38.21 μM, 54.58 μM, 81.88 μM, 109.17 μM, 163.76 μM, 218.34 μM, 272.92 μM, 327.51 μM and 436.68 μM, respectively. The reaction was carried out for 3 min to obtain a reaction system.

[0040] Figure 2 This is the UV-Vis graph of MnCo@C NCs catalyzing different concentrations of adrenaline in this example. It can be seen from the figure that with the increase of adrenaline concentration, its absorbance value at 485nm gradually increases. When the concentration exceeds 272.92μM, the absorbance value hardly changes significantly, indicating that the catalytic ability of MnCo@C NCs has reached saturation.

[0041] (4) Record the absorbance value A of each sample at a wavelength of 485 nm after the reaction to obtain the detection linear relationship between the adrenaline concentration and the absorbance value A. According to the detection linear relationship between the adrenaline concentration and the absorbance value A obtained above, and the absorbance value of the sample to be tested containing adrenaline, the concentration of adrenaline in the sample to be tested is obtained.

[0042] In this embodiment, the absorbance is measured by placing the sample in a UV-visible spectrophotometer and measuring the absorbance at 485 nm.

[0043] Figure 3 : is the linear regression diagram of the detection of different concentrations of adrenaline and absorbance value A in this embodiment. Figure 3 It can be seen that the absorbance value A increases with the increase of adrenaline concentration, and the absorbance value A shows a good linear relationship with the adrenaline concentration. The linear regression equation for the detection is:

[0044] A=0.0035C EP +0.0153 (0.54μM~109.2μM) and A=0.0005C EP +0.33 (109.2μM~272.9μM) (1)

[0046] In formula (1), A represents the absorbance value, C EP is the concentration of adrenaline in the test solution, the unit of which is μM. The correlation coefficient R of formula (1) 2 =0.991 and 0.994, the linear detection range of adrenaline is 0.54μM~272.9μM, and the detection limit is 0.68μM.

[0047] In this embodiment, when performing step (3), when MnCo@C NCs are added to the morpholineethanesulfonic acid buffer solution without adrenaline to obtain a reaction system, the reaction system is almost colorless. When the sample to be tested containing adrenaline is added, the reaction system is yellow-brown, thereby qualitatively detecting whether the sample to be tested contains adrenaline, and the color depth of the reaction system can be qualitatively judged The trend of the change in adrenaline concentration.

[0048] Example 2

[0049] Example 2

[0050] Wherein, in step (1), the mass ratio of manganese acetate to PVP is 1:10, the molar ratio of Mn to Co is 1:3, and the mixture is incubated at room temperature to obtain a MnCo precursor; the mass ratio of dopamine to the MnCo precursor is 1:3.

[0051] The rest is the same as in Example 1.

[0052] It should be noted that the properties of the MnCo@C NCs prepared in Example 2 are the same as those of the MnCo@CNCs prepared in Example 1, and they also have good catalytic activity for adrenaline.

[0053] It can be seen that the rapid colorimetric analysis method based on MnCo@C NCs active materials of the present invention can be used for the detection of catecholamines.

[0054] Actual sample feasibility analysis

[0055] The feasibility of the method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials in Example 1 was evaluated using actual samples. The standard addition method was used to detect the target substances in the actual samples using the colorimetric detection method, and a recovery experiment was performed.

[0056] (1) The concentration of adrenaline in serum samples was determined by the colorimetric analysis method of Example 1. The specific steps were as follows: different serum samples were treated with 10% perchloric acid to remove the protein in the serum, filtered through a 0.22 μm membrane, the supernatant was diluted with morpholineethanesulfonic acid buffer solution, and the adrenaline in the test solution was determined by the colorimetric detection method of Example 1. The concentration of adrenaline added to the sample is shown in Table 1.

[0057]

[0058] As can be seen from Table 1, the method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials of the present invention has a recovery rate of 93% to 103.5% within the measurable concentration range, and the measurement results are ideal, indicating that the colorimetric detection method is feasible for detecting actual samples.

[0059] Anti-interference ability inspection

[0060] The anti-interference ability of the method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials in Example 1 was evaluated. The colorimetric detection method in Example 1 was used to detect common interfering substances in serum (uric acid, urea, glucose, fructose, K + 、Na + , Ca 2+ Mg 2+ , glutamic acid, histidine, cysteine) were measured with higher concentrations of A and numbered Blank, Urea, UA, Glu, Fru, K + 、Na + , Ca 2+ Mg 2+ , His, Glut and Cys, the test results are as follows Figure 4As shown in the figure, the rapid colorimetric analysis method for adrenaline based on active materials of the present invention has strong anti-interference ability, and the absorbance of adding other interfering substances hardly changes, except for cysteine. In the actual detection process, the interference of cysteine ​​can be shielded by adding N-ethylmaleimide masking agent. This shows that the colorimetric detection method of the present invention has good anti-interference ability.

[0061] The above test results show that the anti-interference ability of the method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials of the present invention has the advantages of high stability, strong universality, high sensitivity, etc., and can be used for the detection of adrenaline in human body fluids, thereby diagnosing human health.

[0062] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as above in the preferred embodiment, it is not used to limit the present invention. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention, still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials, characterized in that: The MnCo@CNCs is a core-shell structure, the core is MnCo bimetallic oxide, and the shell is a porous carbon shell C NCs. The method comprises the following steps: S1. Preparation of MnCo@C NCs active materials: S1.1, dispersing manganese acetate and PVP in a mixed solution of ethanol and water and stirring, adding potassium cobalt cyanide aqueous solution, incubating at room temperature, to obtain a MnCo precursor; S1.2, re-dispersing the MnCo metal organic complex into an aqueous solution, then adding a dopamine aqueous solution, reacting at room temperature, and obtaining a polydopamine-coated MnCo precursor; S1.3, pyrolyzing the polydopamine-coated MnCo precursor obtained above at high temperature to obtain a MnCo bimetallic oxide porous carbon active material with a core-shell structure, namely, MnCo@C NCs; S2, adding the MnCo@C NCs active material prepared above to a plurality of morpholineethanesulfonic acid buffer samples containing different concentrations of catecholamines to obtain a mixed system, recording the absorbance value A of each sample at a wavelength of 485 nm after the reaction, and obtaining the detection linear relationship between the catecholamine concentration and the absorbance value A; S3. According to the linear relationship between the catecholamine concentration and the absorbance value A obtained above, and the absorbance value of the sample containing catecholamine, the concentration of catecholamine in the sample to be tested is obtained.

2. The method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials according to claim 1, characterized in that: In step S2, when MnCo@C NCs are added to a morpholineethanesulfonic acid buffer solution that does not contain catecholamines, the reaction system is almost colorless; when a test sample containing catecholamines is added, the reaction system undergoes a color reaction and turns red, thereby qualitatively detecting whether the test sample contains catecholamines.

3. The method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials according to claim 1, characterized in that: The catecholamines include epinephrine EP; the detection linear regression equation of the EP concentration and the absorbance value A is: When the concentration of 2,4-DP is 0.54μM~109.2μM, A = 0.0035 C EP + 0.0153 (1); When the concentration of 2,4-DP is 109.2μM~272.9μM, A=0.0005C EP + 0.33 (2); In formula (1) and (2), A represents the absorbance value, C EP is the concentration of adrenaline in the test solution, the unit of which is μM. The correlation coefficient R of formula (1) 2 = 0.991, the correlation coefficient R of formula (2) 2 = 0.994, the linear detection range of EP is 0.54μM~272.9μM, and the detection limit is 0.68μM.

4. The method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials according to any one of claims 1 to 3, characterized in that: In step S1.1, the mass ratio of manganese acetate to PVP is 1:5-10, and the molar ratio of Mn to Co is 1:1-3.

5. The method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials according to any one of claims 1 to 3, characterized in that: In step S1.2, the mass ratio of dopamine to MnCo precursor is 1:1-3.

6. The method for rapid colorimetric analysis of catecholamines based on MnCo@C NCs active materials according to any one of claims 1 to 3, characterized in that: In step S2, the reaction time is 3 min to 10 min, and the concentration of morpholineethanesulfonic acid is 30 mM to 50 mM.

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