Preparation method and detection method of pyruvic aldehyde electrochemical sensor based on electro-activated gold electrode
Through the preparation method of electroactivated gold electrode, the complexity and high cost of the electrochemical sensor of acetone aldehyde is solved, and sensitive and fast acetone aldehyde detection is achieved, with good reproducibility and environmental protection characteristics.
Patent Information
- Application Number
- CN202510508668.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-22
- Publication Date
- 2025-07-18
AI Technical Summary
The existing method for preparing acetone aldehyde electrochemical sensors is complex, the materials are expensive and time-consuming, and the reproducibility is poor, and the detection method based on electroactivated gold electrodes has not been reported.
Using the preparation method of electroactivated gold electrode, the cyclic voltammetry test is performed by polishing the bare gold electrode on a polishing cloth and performing cyclic voltammetry in K3[Fe(CN)6] solution, followed by electroactivated in KOH solution to form an oxide layer to improve the sensing interface, and the detection is carried out in combination with cyclic and square wave voltammetry.
A sensitive and fast acetone aldehyde detection is achieved, with a detection limit as low as 0.41μM, a wide linear range, good detection stability, simple and environmentally friendly method.
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Figure CN120334314A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of analytical detection, and relates to a preparation method and a detection method of an acetolactaldehyde electrochemical sensor based on an electro-activated gold electrode. Background Art
[0002] Acetolactaldehyde is a reactive dicarbonyl compound produced during the metabolism of glucose, amino acids, and fatty acids in organisms. An increase in its concentration is often closely related to diabetes, cardiovascular diseases, tumors, hyperalgesia, and kidney diseases in humans, and also inhibits the ripening of plant fruits. In addition, it is formed in foods through the Maillard reaction and the autoxidation of fatty acids, endowing foods with unique flavors, and also producing toxic substances such as advanced glycation end products, acrylamide, and methylimidazole. Therefore, the quantitative detection of acetolactaldehyde is of great significance for ensuring physical health and food quality and safety.
[0003] Since acetolactaldehyde contains an electroactive group - aldehyde group (-CHO), a rapid, sensitive, economical, and green electrochemical sensing and detection method can be constructed using its irreversible oxidation peak on the electrode surface. Among them, the surface of the working electrode serves as the sensing interface for acetolactaldehyde molecules and is the core of the preparation of electrochemical sensors.
[0004] Currently, materials such as graphene and carbon nanotubes are mainly used to modify glassy carbon electrodes to construct acetolactaldehyde sensing interfaces. However, the cumbersome operation leads to large batch-to-batch differences, poor reproducibility, and high costs, hindering practical applications. More and more studies have shown that the enhanced detection performance of material-modified electrodes comes from the electro-activation effect of the electrodes in the electrolyte solution during the electrode preparation and detection processes. Based on this, electro-activated electrodes that modify the electrode surface by applying a potential or current in the electrolyte solution have gradually received attention due to their significant advantages of simple operation, good reproducibility, and low cost. Among them, carbon-based electrodes are easily electrochemically oxidized and reduced to generate different types and contents of oxygen-containing functional groups and surface defects, becoming the most important and widely used basic electrodes in the research of electro-activated electrodes.
[0005] Carbon electrodes can easily form various oxygen-containing groups, which is helpful for adsorption. In contrast, as an inert noble metal electrode, due to its strong inertness, it is difficult to oxidize, and it even has a positive effect on quantitative analysis; gold electrodes cannot generate abundant functional groups during the electro-activation process, and are considered difficult to increase the recognition sites for analytes. Moreover, due to their large capacitance, the detection baseline is increased, and they are rarely used in electrochemical analysis.
[0006] Traditional detection methods for methylglyoxal concentration, such as liquid chromatography and mass spectrometry, have defects such as long detection time, cumbersome process, and expensive instruments. And a large amount of organic reagents are used during the detection process. Electrochemical detection methods have become the most promising rapid detection methods at present due to their simple and fast characteristics. The construction of the working electrode sensing interface is the core of the preparation of electrochemical sensors. Among them, the surface of the gold electrode can be combined with a suitable modifier through gold-sulfur bonds, allowing the preparation of a specific sensing interface, which is widely used in the fields of chemical and biological sensing. All detection methods based on gold electrodes for methylglyoxal adopt material modification to construct the sensing interface of the gold electrode, such as carbon nanomaterials, metal nanomaterials, metal-organic framework materials, etc. Although these methods can effectively improve the performance of the sensor, they have deficiencies such as complex preparation methods, expensive materials, and long time consumption.
[0007] Electrochemical detection based on electro-activated electrodes has great application potential in people's production and life, but the same electro-activation method often shows different or even opposite effects on the detection of different analytes. Since the electro-activation method will have an obvious impact on the detection performance of analytes, constructing a suitable electro-activation strategy for analytes is the key point and difficulty in the research of electrochemical detection methods based on electro-activated electrodes. At present, there is no research on the detection method of methylglyoxal based on electro-activated gold electrodes, and there is no report on the construction of electrochemical sensors based on electro-activated gold electrodes. Summary of the Invention
[0008] In view of this, in order to solve the problems of complex preparation method, expensive materials, long time consumption, and poor reproducibility of the methylglyoxal electrochemical sensor, the present invention provides a preparation method and a detection method for a methylglyoxal electrochemical sensor based on an electro-activated gold electrode.
[0009] In order to solve the problems existing in the prior art, the technical solution adopted by the present invention is: a preparation method for a methylglyoxal electrochemical sensor based on an electro-activated gold electrode, the steps are as follows:
[0010] 1) After polishing the bare gold electrode (AuE) into a mirror surface with Al2O3 powder on a polishing cloth, wash it with distilled water, and place the prepared electrode in a K3[Fe(CN)6] solution;
[0011] 2) Perform testing by cyclic voltammetry. If the potential difference between the oxidation and reduction peak potentials is within 80 mV, the next step can be carried out, otherwise repeat the above steps;
[0012] 3) Place the qualified electrode in a KOH solution with a concentration of 0.1 M and perform electro-activation by cyclic voltammetry.
[0013] Further, in step 1), the diameter of the Al2O3 powder is 0.05 μm.
[0014] Further, in step 2), the voltage of cyclic voltammetry is 0 - 0.6 V; the scanning rate is 50 mV / s.
[0015] Further, in step 3), the potential range of electro - activation is - 2.0 - 2.0 mA, and it cycles 150 times.
[0016] The detection method steps of the methylglyoxal electrochemical sensor based on electro - activated gold electrode are as follows:
[0017] 1) Place the prepared electrode in a blank PBS solution and scan it by cyclic voltammetry for two cycles, then wash it with distilled water;
[0018] 2) Put it into the sample to be tested, perform the test by square - wave voltammetry, and substitute the peak current value into the standard curve for quantitative analysis of methylglyoxal.
[0019] Further, in step 1), the potential range of cyclic voltammetry is - 0.3 V - 0.8 V, and the scanning rate is 50 mV / s.
[0020] Further, in step 1), the concentration of the PBS solution is 0.1 - 0.2 M, and the pH is 6.0 - 8.0.
[0021] Further, in step 2), the potential range of square - wave voltammetry is - 0.3 V - 0.8 V.
[0022] Compared with the prior art, the advantages of the present invention are as follows:
[0023] 1. The present invention utilizes the oxide layer and crystal rearrangement formed during the electro - activation process of the gold electrode to achieve efficient electro - catalysis and recognition of methylglyoxal, providing a new idea for the electrochemical detection of aldehyde compounds.
[0024] 2. The electrochemical sensor of the present invention can achieve sensitive and rapid detection of methylglyoxal.
[0025] 3. The detection limit of the methylglyoxal electrochemical sensor of the present invention is as low as 0.41 μM, and the linear range is 1 - 5×10 4 μM, and the RSD of the sensors prepared in different batches for the detection of methylglyoxal is 0.99%.
[0026] 4. The preparation method of the present invention is simple, the conditions are mild, and it is green and environmentally friendly.
[0027] 5. Based on the research status that different analytes show different or even opposite effects in the detection using the same electro - activation method, the present invention constructs an electro - activated gold electrode for the electrochemical detection of methylglyoxal. Description of the Drawings
[0028] Figure 1 It is the cyclic voltammetry electro - activation spectrum of AuE in 0.1 M H2SO4, NaOH, and KOH solutions.
[0029] Figure 2 are the surface energy spectra of the electro-activated AuE and bare AuE in 0.1 M H2SO4, NaOH, and KOH solutions.
[0030] Figure 3 are the X-ray photoelectron spectroscopy (XPS) spectra of the electro-activated AuE and bare AuE surfaces in 0.1 M H2SO4, NaOH, and KOH solutions.
[0031] Figure 4 are the X-ray diffraction (XRD) patterns of the electro-activated AuE and bare AuE surfaces in 0.1 M H2SO4, NaOH, and KOH solutions.
[0032] Figure 5 are the square wave voltammetry curves of the electro-activated AuE and un-electro-activated AuE for methylglyoxal detection in 0.1 M H2SO4, NaOH, and KOH solutions.
[0033] Figure 6 are the electrochemical response diagrams of methylglyoxal detected by KOH-activated AuE (KOH / AuE) under different conditions and the electrode reaction formula of methylglyoxal; where: (A) is the electrochemical response of methylglyoxal on KOH-activated AuE (KOH / AuE) under different detection modes; (B) is the line graph of the peak current value of methylglyoxal at different incubation times; (C) is the square wave voltammetry curve of methylglyoxal detection in electrolyte solutions with different pH values; (D) is the line graph of the peak current and peak potential of methylglyoxal in electrolyte solutions with different pH values; (E) is the electrode reaction formula of methylglyoxal.
[0034] Figure 7 are the performance evaluation diagrams of the electrochemical method for detecting methylglyoxal based on KOH-activated AuE (KOH / AuE); where: (A) is the standard curve of methylglyoxal detection by KOH / AuE; (B) are the peak current values of methylglyoxal obtained from 10 tests. Detailed implementation manner
[0035] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the following further details the present invention in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0036] The preparation method of the methylglyoxal electrochemical sensor based on the electro-activated gold electrode of the present invention is as follows:
[0037] After polishing the bare gold electrode (AuE) into a mirror surface with Al2O3 powder with a diameter of 0.05 μm on a polishing cloth, it was washed with distilled water. The prepared electrode was placed in a K3[Fe(CN)6] solution and tested by cyclic voltammetry within the range of 0 - 0.6 V with a scanning rate of 50 mV / s. Only when the potential difference between the oxidation and reduction peak potentials is within 80 mV can the next step be carried out; otherwise, the above steps are repeated. The qualified electrode was placed in a KOH solution with a concentration of 0.1 M and electro-activated by cyclic voltammetry with a potential range of -2.0 - 2.0 V for 150 cycles.
[0038] The detection method of the methylglyoxal electrochemical sensor based on the electro-activated gold electrode is as follows:
[0039] The prepared electrode was scanned twice by cyclic voltammetry in a blank PBS solution and washed with distilled water. Then, it was placed in the sample to be tested and tested by square wave voltammetry. The peak current value was substituted into the standard curve for quantitative analysis of methylglyoxal. The potential range of the cyclic voltammetry is -0.3 V - 0.8 V, and the scanning rate is 50 mV / s. The concentration of the PBS solution is 0.1 - 0.2 M, and the pH is 6.0 - 8.0. The potential range of the square wave voltammetry is -0.3 V - 0.8 V.
[0040] Based on the research status that different analytes show different or even opposite effects in the detection based on the same electro-activation method. The present invention constructs an electro-activated gold electrode for methylglyoxal electrochemical detection with a detection limit as low as 0.41 μM.
[0041] In order to study the influence of electro-activation on the surface of the gold electrode, the KOH electro-activated gold electrode (KOH / AuE) with a KOH solution concentration of 0.1 M, a potential range of -2.0 - 2.0 V, and 150 cycles was compared with the gold electrodes electro-activated in H2SO4 and NaOH under the same conditions (H2SO4 / AuE, NaOH / AuE).
[0042] From Figure 1 it can be seen that: in H2SO4, a violent hydrogen evolution reaction (HER) occurs on the surface of AuE, and an electro-oxidation peak (A2) and a reduction peak (C1) are generated during the potential cycling process. While in an alkaline solution, the HER during electro-activation is not violent, but there will be a more complex oxidation-reduction process. To further study the influence of this on the surface of the gold electrode, EDS, XPS, and XRD were used to characterize the changes of the electrode after electro-activation in different solutions.
[0043] From Figure 2It can be seen that there are obvious K and Na signals on the surfaces of KOH / AuE and NaOH / AuE, indicating that alkali metal ions are adsorbed on the electrode surface during the electroactivation process. This is beneficial to reducing the work function of the reaction and accelerating the catalytic reaction of the analyte on the electrode surface.
[0044] As can be seen from Figure 3 : at 83.8 and 87.5 eV, Au4f 7 / 2 and 4f 5 / 2 characteristic peaks appear for all four electrodes. In addition, the characteristic peak at 85.9 eV represents the oxide existing in the form of Au(OH)3, AuOOH or Au2O3. From the formula:
[0045]
[0046] where I is the photoelectron intensity, F is the X-ray intensity, α is the photoelectron cross-section energy, D is the atomic density of the substance under study, k is the spectrometer parameter, and x is the thickness of the material under study. The oxide layer thicknesses of KOH / AuE, NaOH / AuE and H2SO4 / AuE are 3.82, 2.58 and 0.99 times that of the bare AuE, respectively. This shows that the oxide layer thickness of the AuE electroactivated in KOH and NaOH increases significantly. The oxide layer is divided into a single oxide layer (α layer) and a hydrated oxide layer (β layer). The increase in the oxide layer thickness means the thickening of the β layer, which can wrap Na + or K + inside, strengthening the stability of the electrode surface after electroactivation.
[0047] As can be seen from Figure 4 : compared with the bare AuE, the Au(220) crystal plane appears on the surface of the electroactivated AuE electrode. This indicates that during the electroactivation process, crystal rearrangement occurs on the electrode surface. The crystal defects generated during this process are beneficial to promoting the detection of the analyte.
[0048] The above results show that electroactivation can achieve surface modification of the gold electrode and produce structural changes that affect the electrode reaction of the analyte.
[0049] To study the influence of the above changes on the detection of methylglyoxal, the bare AuE and different electroactivated AuE were used to detect methylglyoxal. As can be seen from Figure 5 : KOH / AuE has the most obvious improvement effect on methylglyoxal compared with the bare AuE, indicating that the gold electrode electroactivated in KOH is most suitable for the detection of methylglyoxal.
[0050] To establish a detection method based on the electroactivated gold electrode, the effects of different detection modes, incubation times and electrolyte pH were studied, as Figure 6 shown: Figure 6(A) It was found through comparison that there were obvious reduction peak signals of methylglyoxal in square wave voltammetry (SWV) and differential pulse voltammetry (DPV) modes. The peak potential was in the range of 0.55 - 0.6 V. Secondly, this reduction peak was not obvious in cyclic voltammetry (CV) and linear sweep voltammetry (LSV) curves. To achieve rapid detection of methylglyoxal, the more time-saving SWV mode was used in subsequent detections. Figure 6 (B) The incubation time had an obvious impact on the detection of methylglyoxal, and with the increase of the incubation time, the response signal of methylglyoxal decreased. It indicated that methylglyoxal did not need to adsorb for a long time on this sensing interface and could be detected immediately with good detection results. Figure 6 (C) PBS with different pH values was used to prepare the methylglyoxal detection solution, and the detection of methylglyoxal by KOH / AuE was analyzed. From Figure 6 (D), it can be seen that the peak current showed a trend of first increasing and then decreasing with the increase of the pH value, and reached the maximum value at 9.0. The peak potential decreased linearly with the increase of pH, and the slope was -0.07 V / pH. Based on this, the ratio of the number of protons to the number of electrons participating in the reaction was calculated to be 2:2. Therefore, the electrode reaction was as Figure 6 (E) shown.
[0051] To study the linear relationship of methylglyoxal on KOH / AuE, KOH / AuE was used to test methylglyoxal with different concentrations. As Figure 7 (A) shown, the peak current increased with the increase of the methylglyoxal concentration, and there was a good linear relationship. In the range of 1 - 50 μM, the linear equation was: I(μA) = 0.076C(μM) - 1.37 (R 2 = 0.995). In the range of 5×10 1 - 5×10 4 μM, the linear equation was: I(μA) = 1.2C(mM) + 4.96 (R 2 = 0.994). The detection limit was 0.41 μM. To study the stability of the sensing interface prepared by this regulation method for the detection of methylglyoxal, the repeatability of the methylglyoxal detection signal by KOH / AuE was tested. As Figure 7 (B) shown, through 10 repeated experiments, the RSD of the methylglyoxal current value was 0.99%, indicating that the detection of methylglyoxal had good stability.
[0052] The above is only the preferred embodiment of the present invention and is not used to limit the protection scope of the present invention.
Claims
1. Preparation method of methylglyoxal electrochemical sensor based on electro-activated gold electrode, characterized in that: The steps are as follows: 1) After polishing the bare gold electrode (AuE) into a mirror surface with Al2O3 powder on a polishing cloth, wash it with distilled water and place the prepared electrode in a K3[Fe(CN)6] solution; 2) Conduct a test using cyclic voltammetry. If the potential difference between the oxidation and reduction peak potentials is within 80 mV, proceed to the next step; otherwise, repeat the above steps; 3) Place the qualified electrode in a 0.1 M KOH solution and conduct electroactivation using cyclic voltammetry.
2. The preparation method of the methylglyoxal electrochemical sensor based on an electro-activated gold electrode according to claim 1, wherein: In step 1), the diameter of the Al2O3 powder is 0.05 μm.
3. The preparation method of the methylglyoxal electrochemical sensor based on an electro-activated gold electrode according to claim 1 or 2, characterized in that: In step 2), the voltage of cyclic voltammetry is 0 - 0.6 V; the scanning rate is 50 mV / s.
4. The preparation method of the methylglyoxal electrochemical sensor based on an electro-activated gold electrode according to claim 1, characterized in that: In step 3), the potential range of electroactivation is -2.0 to 2.0 mA, and it cycles 150 times.
5. Detection method of methylglyoxal electrochemical sensor based on electroactivated gold electrode, characterized in that, The steps are as follows: 1) Place the prepared electrode in a blank PBS solution and scan it twice using cyclic voltammetry, then wash it with distilled water; 2) Put it into the sample to be tested, conduct a test using square wave voltammetry, and substitute the peak current value into the standard curve for quantitative analysis of methylglyoxal.
6. The detection method of the methylglyoxal electrochemical sensor based on an electroactivated gold electrode according to claim 5, characterized in that, In step 1), the potential range of cyclic voltammetry is -0.3 V to 0.8 V, and the scanning rate is 50 mV / s.
7. The detection method of the methylglyoxal electrochemical sensor based on an electroactivated gold electrode according to claim 6, wherein, In step 1), the concentration of the PBS solution is 0.1 - 0.2 M, and the pH is 6.0 - 8.
0.
8. The detection method of the methylglyoxal electrochemical sensor based on an electro-activated gold electrode according to claim 7, characterized in that, In step 2), the potential range of square wave voltammetry is -0.3 V to 0.8 V.