Non-enzyme sensitive material for electrochemically and continuously monitoring lactic acid in sweat in real time as well as preparation method and application of non-enzyme sensitive material

Abstract

The invention discloses an enzyme-free sensitive material for electrochemically and continuously monitoring lactic acid in sweat in real time as well as a preparation method and application of the enzyme-free sensitive material, and particularly relates to the field of electrochemical sensing. Comprising the following steps: mixing a CuCl2 solution and NaBH4 to obtain Cu hydrogel; the Cu hydrogel is subjected to freeze drying, and Cu aerogel is obtained; and calcining the Cu aerogel to obtain a non-enzyme sensitive material CuO aerogel, using the non-enzyme sensitive material CuO aerogel to prepare a non-enzyme sensitive chip, and monitoring the content of lactic acid in sweat. The CuO aerogel is used as a sensitive material, the CuO aerogel has a rich hierarchical porous structure and a large specific surface area, mass transfer diffusion in the electrochemical process is accelerated, rich active sites are provided, the sensitivity of sensing detection is further improved, and the lower detection limit of the CuO aerogel is reduced; in addition, the CuO aerogel has excellent stability compared with a biological enzyme in traditional lactic acid sensing, so that the problem of stability reduction caused by enzyme inactivation is avoided.

Description

Technical Field

[0001] This application relates to the field of electrochemical sensing, and in particular to an enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid, its preparation method, and its application. Background Technology

[0002] Lactic acid is an important metabolic byproduct produced during anaerobic glycolysis in the human body. Lactic acid levels are crucial biochemical indicators in the treatment and prognosis of conditions such as tissue hypoxia, liver disease, acidosis, and drug poisoning. Lactic acid is also often referred to as a "training benchmark," as its level in sweat is closely related to tissue oxygenation in muscle cells. Therefore, real-time and continuous monitoring of sweat lactate levels is of paramount importance for clinical diagnosis and scientific training.

[0003] Using sweat as a biofluid, real-time continuous monitoring of lactic acid in sweat offers significant advantages, including being painless and non-invasive, easy to collect, enabling real-time in-situ continuous monitoring, and allowing for personalized monitoring. Wearable biosensors can achieve real-time continuous monitoring of lactic acid in sweat. Electrochemical sensing technology, due to its simple design, low cost, high sensitivity, fast response, high selectivity, real-time continuous monitoring, and ease of miniaturization and deviceization, is currently widely used in the field of biosensing.

[0004] Existing lactic acid electrochemical sensing technologies are mainly divided into enzyme-based and enzyme-free sensing. Lactic acid sensors based on enzyme electrodes typically utilize lactate oxidase or lactate dehydrogenase to achieve sensitive detection of lactic acid. However, the high cost and susceptibility of enzyme activity to external environmental interference severely limit the sensitivity and long-term stability of enzyme-based lactic acid electrochemical sensors. Enzyme-free sensors, on the other hand, mostly use inorganic materials, eliminating the need to consider enzyme inactivation. However, the current methods for preparing enzyme-free lactic acid-sensitive materials are complex and not conducive to industrial production. Summary of the Invention

[0005] The main objective of this application is to provide an enzyme-free sensitive material for real-time continuous electrochemical monitoring of lactic acid in sweat, its preparation method, and its application, aiming to solve the problem of complex preparation of existing lactic acid sensitive materials.

[0006] To achieve the above objectives, this application provides a method for preparing an enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid, comprising: mixing CuCl2 solution and NaBH4 to obtain Cu hydrogel; freeze-drying the Cu hydrogel to obtain Cu aerogel; and calcining the Cu aerogel at a temperature of 300~400 ℃ for 2~4 h to obtain an enzyme-free sensitive material CuO aerogel.

[0007] Optionally, the molar ratio of CuCl2 solution to NaBH4 is 1:3~10, and the molar concentration of CuCl2 solution is 0.1 M.

[0008] Optionally, the reaction time between CuCl2 solution and NaBH4 is 6–12 h.

[0009] Optionally, during the calcination process, the heating rate is 3~8 ℃ / min.

[0010] To achieve the above objectives, this application provides an enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid, which is obtained through the above preparation method.

[0011] To achieve the above objectives, this application provides an enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid, and its application in monitoring sweat lactic acid.

[0012] Optionally, enzyme-free CuO aerogel can be used to prepare enzyme-free sensitive chips, which can be used to monitor the lactic acid content in sweat.

[0013] Optionally, the preparation method of the enzyme-free sensitive chip is as follows: the enzyme-free sensitive material CuO aerogel is drop-coated onto the electrode surface and dried to obtain the enzyme-free sensitive chip.

[0014] Compared with the prior art, the beneficial effects of this application are as follows: The present invention relates to an enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid, using CuO aerogel as the sensitive material. CuO aerogel has a rich hierarchical porous structure and a large specific surface area, which is beneficial for accelerating mass transfer and diffusion in the electrochemical process and provides abundant active sites, thereby improving the sensitivity of the sensing and reducing its detection limit. In addition, CuO aerogel has excellent stability compared with the biological enzymes in traditional lactic acid sensors, which can avoid the problem of stability reduction caused by enzyme inactivation, thus exhibiting excellent stability in the application of real-time continuous electrochemical monitoring of sweat lactic acid.

[0015] The present invention provides a method for preparing an enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid. This method synthesizes CuO aerogel through a simple one-step reduction combined with high-temperature oxidation, which is easy to implement and inexpensive. Attached Figure Description

[0016] Figure 1 This is a SEM image of the enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid in this application. Figure 2 The XRD pattern of the enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid in this application; Figure 3Nitrogen adsorption-desorption isotherm and pore size distribution diagram of the enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid in this application; Figure 4 The CV curves of CuO / GCE for lactic acid at 0 mM and 30 mM in Example 3 are shown. Figure 5 The graphs show the it curve and calibration curve of CuO / GCE in Example 3; Figure 6 The graph shows the selectivity results of CuO / GCE detection of lactic acid in Example 3; Figure 7 The figure shows the results of continuous monitoring of lactic acid stability and long-term stability test of CuO / GCE in Example 3. Figure 8 The graph shows the test results of CuO / SPE in Example 4.

[0017] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] The first embodiment of the present invention provides a method for preparing an enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid, specifically including the following steps: Step S1: Mix CuCl2 solution and NaBH4 to obtain Cu hydrogel; wherein the molar ratio of CuCl2 solution to NaBH4 is 1:3~10, the molar concentration of CuCl2 solution is 0.1 M, and the reaction time of CuCl2 solution and NaBH4 is 6~12 h.

[0020] Specifically, CuCl2 solution and NaBH4 were mixed and stirred with a magnetic stirrer at a speed of 1000-2000 rpm for 30-60 s. After stirring, a black solution was obtained. The black solution was stored in the dark for 8 h, and the black solid that appeared in the solution was Cu hydrogel.

[0021] Step S2: Freeze-dry the Cu hydrogel to obtain Cu aerogel; Specifically, before freeze-drying, the Cu hydrogel needs to be washed with ultrapure water 8 to 10 times to remove residual impurity ions. The black powder sample obtained by freeze-drying is the Cu aerogel.

[0022] Step S3 involves calcining the Cu aerogel at 300–400 °C for 2–4 h to obtain an enzyme-free CuO aerogel. During calcination, the heating rate is 3–8 °C / min.

[0023] Specifically, the Cu aerogel is transferred to a tube furnace and heated to 300 °C in an air atmosphere at a rate of 5 °C / min. After calcination, the resulting black powdery sample is the enzyme-free CuO aerogel.

[0024] In this embodiment, CuO aerogel is synthesized using CuCl2 solution and NaBH4 as raw materials via a one-step reduction combined with high-temperature oxidation method. This method is simple and easy to implement. The resulting CuO aerogel possesses a rich hierarchical porous structure and a large specific surface area, which is beneficial for accelerating mass transfer and diffusion during the electrochemical process and provides abundant active sites, thereby improving the sensitivity of the sensor and lowering its detection limit. Furthermore, the CuO aerogel exhibits high electrochemical activity, capable of undergoing a redox reaction with lactic acid under neutral to slightly acidic conditions. During the electrochemical reaction, Cu(II) is reduced to Cu(I), becoming an oxidizing active intermediate that catalyzes the oxidation of lactic acid. A current response is generated during the aforementioned oxidation and reduction reactions, thus enabling the electrochemical detection of lactic acid in sweat.

[0025] The second embodiment of the present invention provides an enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid, which is obtained by the above preparation method.

[0026] In order to test the sensitivity of the enzyme-free sensitive material obtained in this embodiment to lactic acid in sweat, it is necessary to prepare the enzyme-free sensitive material into an electrode and test the electrode. The specific electrode preparation and testing methods are as follows.

[0027] Step S4, preparing the sensitive material dispersion: Weigh more than 2 mg of CuO aerogel, add ultrapure water to it to obtain a CuO aerogel aqueous solution with a concentration of 2 mg / mL; add Nafion perfluorinated resin to the CuO aerogel aqueous solution, and sonicate the mixture for about 1 h until it is uniformly dispersed to obtain a CuO aerogel dispersion with a concentration of 2 mg / mL, wherein the Nafion perfluorinated resin accounts for 0.5% of the total volume of the CuO aerogel dispersion; Step S5, Polishing the glassy carbon electrode (GCE): Wet the chamois leather with ultrapure water, and sprinkle 0.5 μm diameter alumina polishing powder onto the wet chamois leather; hold the GCE (Φ=3 mm) vertically and polish its surface on the chamois leather in a figure-eight shape. Subsequently, the polished GCE is ultrasonically cleaned sequentially in ultrapure water, ethanol, and ultrapure water, and then dried under a nitrogen atmosphere to obtain a clean GCE.

[0028] Step S6: Prepare an enzyme-free sweat lactic acid sensitive electrode based on CuO aerogel: Take 5 μL of CuO aerogel dispersion, uniformly drop it onto the surface of GCE, and place it under an infrared baking lamp to dry, thus obtaining an enzyme-free sweat lactic acid sensitive electrode based on CuO aerogel (CuO / GCE).

[0029] In step S7, using CuO / GCE as the working electrode, platinum wire as the counter electrode, and a silver / silver chloride (Ag / AgCl) electrode as the reference electrode, sodium dihydrogen phosphate (NaH2PO4) and disodium hydrogen phosphate (Na2HPO4) are mixed in ultrapure water, and the pH is adjusted with sodium hydroxide (NaOH) solution to obtain a 0.1 M phosphate buffered saline (PBS) solution with a pH of 6.5, which is used as the electrolyte.

[0030] Step S8 involves electrochemical testing of the CuO / GCE electrode using cyclic voltammetry (CV) and amperometric-time (it) methods. CV testing is primarily used to qualitatively determine the electrochemical response of CuO / GCE to different concentrations of lactic acid; the CV testing window is set to -0.4 to 0.3 V, and the scan rate is set to 50 mV / s. It testing is mainly used to establish a calibration curve for the CuO / GCE response to lactic acid, and to test the selectivity of CuO / GCE, the stability of continuous lactic acid monitoring, and the long-term stability of the sensitive material; the potential for it testing is set to -0.1 V.

[0031] The above method can be used to determine the sensing performance of enzyme-free sensitive materials in detecting lactic acid in sweat.

[0032] A third embodiment of the present invention provides the application of an enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid. Specifically, the enzyme-free sensitive material is used to prepare an enzyme-free sensitive chip, which is then used to monitor the lactic acid content in sweat.

[0033] Furthermore, the preparation method of the enzyme-free sensitive chip is as follows: an enzyme-free sensitive material is drop-coated onto the electrode surface and dried to obtain the enzyme-free sensitive chip. For example, the electrode can be a screen-printed electrode (SPE). Before use, the SPE is rinsed with ultrapure water and dried under a nitrogen atmosphere. 5 μL of CuO aerogel dispersion is uniformly drop-coated onto the SPE surface and dried under an infrared baking lamp to obtain an enzyme-free sensitive chip based on CuO aerogel (CuO / SPE). The CuO / SPE is then brought into contact with sweat, and CV and it tests are used to evaluate the sensing performance of CuO / SPE for different concentrations of lactic acid in artificial sweat at pH 6.5. The CV test window is set to -0.6~0.4 V, and the scan rate is set to 50 mV / s; the it test potential is set to -0.1 V.

[0034] Example 1 Step 1: Mix 0.1 M CuCl2 solution and NaBH4 at a molar ratio of 1:3, and stir with a magnetic stirrer at 1800 rpm for 50 s to obtain a black solution. Store the black solution in the dark for 8 h to obtain Cu hydrogel.

[0035] Step 2: Wash the Cu hydrogel with ultrapure water 8 times and freeze-dry it to obtain Cu aerogel; Step 3: Transfer the Cu aerogel to a tube furnace and heat it to 300°C in air at a rate of 5°C / min, and hold for 3 hours to obtain CuO aerogel.

[0036] Example 2 Step 1: Mix 0.1 M CuCl2 solution and NaBH4 at a molar ratio of 1:10, and stir with a magnetic stirrer at 1800 rpm for 50 s to obtain a black solution. Store the black solution in the dark for 8 h to obtain Cu hydrogel.

[0037] Step 2: Wash the Cu hydrogel with ultrapure water 8 times and freeze-dry it to obtain Cu aerogel; Step 3: Transfer the Cu aerogel to a tube furnace and heat it to 300°C in air at a rate of 5°C / min, and hold for 3 hours to obtain CuO aerogel.

[0038] Example 3 Step 1: Mix 0.1 M CuCl2 solution and NaBH4 at a molar ratio of 1:5, and stir with a magnetic stirrer at 1800 rpm for 50 s to obtain a black solution. Store the black solution in the dark for 8 h to obtain Cu hydrogel.

[0039] Step 2: Wash the Cu hydrogel with ultrapure water 8 times and freeze-dry it to obtain Cu aerogel; Step 3: Transfer the Cu aerogel to a tube furnace and heat it to 300°C in air at a rate of 5°C / min, and hold for 3 hours to obtain CuO aerogel.

[0040] The microstructure and structure of the CuO aerogel obtained in Example 3 were characterized using scanning electron microscopy (SEM). (See attached image.) Figure 1 As shown in the figure, CuO aerogel has a loose and porous three-dimensional network structure, which can accelerate mass transfer and diffusion in the electrochemical process. This is beneficial to improving the sensitivity of the enzyme-free CuO aerogel to the response of sweat lactic acid and lowering its detection limit.

[0041] The crystal structure of the CuO aerogel was further determined by X-ray diffraction (XRD). Figure 2 As shown, the CuO aerogel is a monoclinic phase, and the diffraction peaks at 35.5°, 38.7° and 48.7° correspond to the (0 0 2), (1 1 1) and (-20 2) crystal planes of CuO, respectively, indicating that CuO aerogel has been successfully prepared.

[0042] The pore structure and specific surface area of ​​CuO aerogel were analyzed using nitrogen adsorption-desorption tests. Figure 3 As shown, the adsorption isotherms of CuO aerogel exhibit type II and type IV characteristics, indicating that the pore structure in CuO aerogel is distributed in the form of mesopores and macropores. Based on the Brunauer-Emmett-Teller (BET) equation, the average specific surface area of ​​different batches (n=3) of CuO aerogel is calculated to be 27.60 ± 0.88 m². 2 g -1 This indicates that CuO aerogel has a large specific surface area. This demonstrates that CuO aerogel possesses a rich hierarchical porous structure and a large specific surface area, which is beneficial for accelerating mass transfer and diffusion during electrochemical processes and provides abundant active sites, thereby enhancing the sensitive response to target molecules.

[0043] An enzyme-free sweat lactic acid sensitive electrode CuO / GCE was prepared using the methods in steps S4-6, and a three-electrode system was prepared using CuO / GCE using the method in step S7. Electrochemical tests were then performed using the method in step S8, and the test results are as follows.

[0044] CV test results as follows Figure 4 As shown, compared to CuO / GCE without lactic acid, the addition of 30 mM lactic acid significantly increased both the oxidation and reduction currents. This indicates that the CuO / GCE obtained in this embodiment exhibits a sensitive response to lactic acid, which is beneficial for achieving real-time continuous electrochemical monitoring of lactic acid in sweat.

[0045] The IT test results are as follows: Figure 5 As shown, from Figure 5 As can be seen from A, within the response range of 0–50 mM lactic acid, the response current increases with increasing lactic acid concentration. From… Figure 5 As can be seen from B, the detection limit of CuO / GCE for lactic acid is as low as 0.5 mM. From... Figure 5 C shows that within the response range of 0.5~30 mM lactic acid, the linear correlation coefficient (R0) is... 2 The value was 0.984, and the sensitivity was -0.094 ± 0.003 μA mM. -1 cm -2 Within the 30–45 mM lactate response range, R 2 The value is 0.965, and the sensitivity is -6.993 ± 0.948 μAmM. -1 cm -2 This demonstrates that the CuO / GCE prepared in this embodiment exhibits a wide response range, a low detection limit, a high linear response coefficient, and high sensitivity to lactic acid.

[0046] The selectivity of the enzyme-free sensitive material obtained in Example 3 was tested, and the results are as follows: Figure 6 As shown. First, common interfering substances found in sweat were added sequentially at a potential of -0.1V. Specifically, 20 mmol / L Urea, 25 μmol / L UA, 5 mmol / L Glu, 0.5 mmol / L ascorbic acid (AA), 5 mmol / L potassium chloride (KCl), and 75 mmol / L NaCl were added to the PBS buffer. From Figure 6 As can be seen from A and B, the current response generated by these interfering substances is much smaller than the current change caused by the target substance lactic acid, which is 0.10%-5.23% (<10%) of that of 30 mM lactic acid.

[0047] Secondly, considering the possibility of applying sunscreen in practical applications, the main ingredients of the sunscreen were added to the buffer solution in sequence to examine their effect on the lactic acid response. The main ingredients of the sunscreen included 10% bis(ethylhexyloxyphenol) methoxybenzidine (Tinosorb S), 15% cresoltrazol trisiloxane (Mexoryl XL), 10% oxybenzone, 10% octinoxate, 5% octisalate, 25% titanium dioxide (TiO2), and 25% zinc oxide (ZnO). Figure 6As shown in C and D, the current response generated by the main component of sunscreen is significantly smaller than the current change caused by the target substance lactic acid, which is only 0.27%~3.26% (<10%) of that of 30 mM lactic acid. This proves that the enzyme-free sweat lactic acid sensitive electrode CuO / GCE prepared in this embodiment has excellent selectivity for both common interfering substances in sweat and the main component of sunscreen, further demonstrating that the enzyme-free sensitive material has excellent selectivity for both common interfering substances in sweat and the main component of sunscreen. This excellent selectivity is mainly due to the catalytic oxidation effect of the sensitive material on the target substance lactic acid, while the response to other interfering substances is relatively small.

[0048] The long-term stability of the enzyme-free sensitive material obtained in Example 3 was tested, and the results are as follows: Figure 7 As shown. From Figure 7 As can be seen from Figure A, after 4 hours of continuous monitoring of CuO / GCE, the current value remained at 98.28% of the initial value, indicating that the CuO / GCE prepared in this embodiment exhibits excellent stability for continuous monitoring of lactic acid. The sensitive material was stored at room temperature, and its electrochemical response to 20 mM lactic acid was detected in 5-day intervals. After 30 days, the current response still maintained 94.29% of the initial response (see Figure A). Figure 7 (B) This demonstrates that the enzyme-free CuO aerogel, a sweat lactic acid electrochemical sensing material prepared in this embodiment, exhibits excellent long-term stability. This is mainly due to the use of stable inorganic CuO as the sensing material, replacing the use of biological enzymes in traditional lactic acid sensing, thereby avoiding the problem of reduced stability caused by enzyme inactivation.

[0049] Example 4 Step 1: Mix NaCl (20 g / L), NH4Cl (17.5 g / L), Urea (5 g / L), Acetic acid (2.5 g / L), Glu (30.6 mg / L) and UA (9.9 mg / L), and adjust the pH with NaOH solution to prepare artificial sweat with a pH of 6.5. Step 2: 5 μL of CuO aerogel dispersion obtained in Example 3 is uniformly drop-coated onto the surface of SPE and dried under an infrared baking lamp to obtain an enzyme-free sensitive chip based on CuO aerogel (CuO / SPE). Step 3: Place CuO / SPE in artificial sweat for CV and it tests. The test results are shown in [link to results]. Figure 8 .

[0050] First, the CV test results are as follows: Figure 8As shown in the figure, in artificial sweat at pH 6.5, compared to CuO / SPE without lactic acid (0 mM), the addition of 30 mM lactic acid significantly increased both the oxidation and reduction currents. This indicates that the CuO / SPE prepared in this embodiment exhibits a sensitive response to lactic acid, which is beneficial for achieving real-time continuous electrochemical monitoring of lactic acid in sweat.

[0051] Furthermore, the IT test results are as follows: Figure 8 As shown in Figure B, firstly, 5 mM lactic acid was added to artificial sweat at a potential of -0.1 V to test the stability of the sensitive chip's electrochemical real-time continuous monitoring of sweat lactic acid. As can be seen from the figure, after 1 hour of continuous monitoring, the current value remained at 98.13% of the initial value, indicating that the CuO / SPE prepared in this embodiment can achieve electrochemical real-time continuous and stable monitoring of sweat lactic acid. Subsequently, the calibration curve for the sensitive chip's monitoring of sweat lactic acid was also determined by IT testing. Figure 8 As shown in Figure C, within the lactic acid response range of 0–30 mM, the response current of CuO / SPE increases with increasing lactic acid concentration, and the detection limit for lactic acid can reach 0.5 mM. Figure 8 As shown in Figure D, in the calibration curve, within the lactic acid response range of 0.5–10 mM, R 2 The value is 0.989, and the sensitivity is -2.825 ± 0.132 μA mM. -1 cm -2 Within the 10–30 mM lactate response range, R 2 The value is 0.997, and the sensitivity is -1.340 ± 0.051 μA mM. -1 cm -2 This indicates that CuO / SPE exhibits a low detection limit, a wide response range, a high linear response coefficient, and high sensitivity for lactic acid in sweat. This demonstrates that the enzyme-free CuO aerogel material can be used for real-time, continuous electrochemical monitoring of lactic acid in sweat.

[0052] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A method for preparing an enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid, characterized in that, include: CuCl2 solution and NaBH4 were mixed to obtain Cu hydrogel; The Cu hydrogel was freeze-dried to obtain Cu aerogel; The Cu aerogel was calcined at 300-400 °C for 2-4 h to obtain an enzyme-free CuO aerogel.

2. The method for preparing the enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid according to claim 1, characterized in that, The molar ratio of CuCl2 solution to NaBH4 is 1:3~10, and the molar concentration of CuCl2 solution is 0.1 M.

3. The method for preparing the enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid according to claim 1, characterized in that, The reaction time between the CuCl2 solution and NaBH4 is 6-12 h.

4. The method for preparing the enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid according to claim 1, characterized in that, During the calcination process, the heating rate is 3~8 ℃ / min.

5. An enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid, characterized in that, It is obtained by the preparation method according to any one of claims 1-4.

6. The application of the enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid as described in claim 5 in the monitoring of sweat lactic acid.

7. The application of the enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid according to claim 6 in the monitoring of sweat lactic acid, characterized in that, Enzyme-free sensitive materials are used to prepare enzyme-free sensitive chips, which are then used to monitor the lactic acid content in sweat.

8. The application of the enzyme-free sensitive material for real-time continuous electrochemical monitoring of sweat lactic acid according to claim 7 in the monitoring of sweat lactic acid, characterized in that, The method for preparing the enzyme-free sensitive chip is as follows: The enzyme-free sensitive material is drop-coated onto the electrode surface and then dried to obtain an enzyme-free sensitive chip.

Images