Multi-component metal sulfide mimic enzyme material as well as preparation method and application thereof

Abstract

The invention discloses a multi-component metal sulfide mimic enzyme material and a preparation method and application thereof, and relates to a metal sulfide mimic enzyme material and a preparation method thereof. The invention aims to solve the technical problems of harsh conditions and low catalytic performance of the existing preparation method of 1T-phase MoS2. The chemical formula of the multi-component metal sulfide mimic enzyme material disclosed by the invention is FeS2-MoS2. The preparation method comprises the following steps: adding a ferric sulfate aqueous solution into a boiling ammonium molybdate hydrate aqueous solution, uniformly stirring to prepare a precursor, dissolving the precursor and thiourea in water, and carrying out a hydrothermal reaction to obtain the mimic enzyme material. The compound can be used as a colorimetric detection catalyst to catalyze the chromogenic reaction of TMB (tetramethylbenzidine). According to the present invention, the detection limit of H2O2 is 0.52 [mu] M in the H2O2 concentration range of 1-80 [mu] M, and the fluorescent probe has characteristics of interference resistance, colorimetric sensing and peroxidase catalysis performance, and can be used in the field of detection.

Description

Technical Field

[0001] The invention relates to a metal sulfide enzyme-mimicking material and a preparation method and application thereof. Background Art

[0002] Molybdenum disulfide (MoS2) is a promising enzyme-mimicking catalyst material with the advantages of low price, fast redox reaction speed, and good chemical and physical stability. Molybdenum disulfide has a typical two-dimensional sheet structure, usually showing two phases: 1T phase and 2H phase. Studies have shown that 1T phase MoS2 has better catalytic activity than 2H phase MoS2. However, 1T-MoS2 is unstable and can easily transform into stable 2H-MoS2. The Chinese patent application number 202310044646.9, "Preparation and Performance Study of a High 1T-MoS2 Dissimilar Metal Colorimetric Sensor Material", prepared a high MoS2 dissimilar metal colorimetric sensor material, introduced transition metal sulfide ZnS into MoS2, formed a MoS2-based bimetallic heterostructure composite material, and stabilized the structure of 1T-MoS2. The introduction of transition metals played a synergistic role, enhancing the surface area, active heterogeneous interface and abundant active sites of the bimetallic, thereby improving the catalytic performance of the MoS2 material. However, this method has the problem of harsh preparation. At the same time, the ZnS material in the 1T / 2H-MoS2 / ZnS heterostructure composite material does not participate in the catalytic reaction of the peroxidase mimetic enzyme, resulting in low catalytic performance. Summary of the invention

[0003] The present invention aims to solve the technical problems of harsh preparation conditions and low catalytic performance of the existing 1T phase MoS2 preparation method, and to provide a multi-component metal sulfide enzyme-mimicking material and its preparation method and application.

[0004] The chemical formula of the multi-component metal sulfide enzyme-mimicking material of the present invention is FeS2-MoS2.

[0005] The preparation method of the above-mentioned multi-component metal sulfide enzyme-mimicking material is carried out according to the following steps:

[0006] 1. Preparation of polyoxometalate (FeMo6) precursor: Add ammonium molybdate to water at room temperature, stir and heat to boiling, then add iron (III) sulfate solution, react under boiling conditions for 10 to 12 hours, and keep the pH value of the solution between 2.5 and 3.0 during the reaction. After the reaction, filter out the block crystals, recrystallize in hot water to obtain a polyoxometalate (FeMo6) precursor;

[0007] 2. Preparation of multi-component metal sulfide enzyme-mimicking materials: Under ultrasonic conditions, disperse the polyoxometalate (FeMo6) precursor and thiourea in deionized water, mix well and transfer to a Teflon-lined autoclave, and keep it at a temperature of 180-220°C for 8-36 hours; filter the product and wash it with ethanol and water, and then dry it under vacuum to obtain a multi-component metal sulfide enzyme-mimicking material.

[0008] Furthermore, the concentration of the iron (III) sulfate solution in step 1 is 0.05-0.07 g / mL.

[0009] Furthermore, the molar concentration of the ammonium molybdate in step 1 is 0.05-0.06 mmol / mL.

[0010] Furthermore, the molar ratio of iron (III) sulfide to ammonium molybdate in step 1 is 1:(1.4-1.5);

[0011] Furthermore, the temperature of the hot water in step 1 is 75-85°C.

[0012] Furthermore, the mass ratio of the polyoxometalate (FeMo6) precursor to thiourea described in step 2 is 1: (1.5-2.5).

[0013] Furthermore, the concentration of the polyoxometalate (FeMo6) precursor described in step 2 is 1.5-2.5 mg / mL.

[0014] The application of the multi-component metal sulfide enzyme-mimicking material is to use the multi-component metal sulfide enzyme-mimicking material as a colorimetric detection catalyst to catalyze the color development reaction of TMB (3,3'-dimethylbenzidine). The multi-component metal sulfide material has peroxidase activity and has higher catalytic activity than other complexes.

[0015] Compared with the prior art, the advantages of the present invention are as follows:

[0016] 1. The present invention adopts a simple one-step hydrothermal synthesis method to successfully prepare a multi-component metal sulfide material for the first time using iron (III) sulfate, ammonium molybdate hydrate and thiourea; because the multi-component metal sulfide enzyme-mimicking material FeS2-MoS2 has a higher 1T-MoS2 content and defects, and a larger specific surface area, the active sites are increased, so that the multi-component metal sulfide enzyme-mimicking material of the present invention has a higher catalytic activity.

[0017] Second, the colorimetric sensing catalytic performance was tested by ultraviolet spectroscopy, indicating that the multi-component metal sulfide enzyme-mimicking material of the present invention has excellent colorimetric sensing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The PXRD spectrum of the multi-component metal sulfide material prepared in Example 1;

[0019] Figure 2 This is a Raman spectrum of the multi-component metal sulfide material prepared in Example 1;

[0020] Figure 3 This is an X-ray photoelectron spectrum of the multi-component metal sulfide enzyme-mimicking material prepared in Example 1; a is the XPS spectrum of the Mo element, and b is the spectrum of the S element;

[0021] Figure 4 These are microscopic morphology images of the multi-component metal sulfide material prepared in Example 1, wherein a is a scanning electron microscope image, b is a transmission electron microscope image, and c and d are high-resolution transmission electron microscope images.

[0022] Figure 5 Catalytic activity diagram of MoS2 prepared from the multi-component metal sulfide material of Example 1 and Comparative Example 1;

[0023] Figure 6 Calculated specific activity (SA) diagram of the multi-component metal sulfide materials prepared in Examples 1 to 5;

[0024] Figure 7 PXRD spectra of the multi-component metal sulfide materials prepared in Examples 1 to 5;

[0025] Figure 8 Specific surface area diagram of the multi-component metal sulfide materials prepared in Examples 1 to 5;

[0026] Fig. 9 XPS spectra of the Mo element in the multi-component metal sulfide material FeS2-MoS2 prepared in Examples 1 to 5;

[0027] Fig.10 The multi-component metal sulfide materials 1T phase MoS2, 2H phase MoS2 and defect content diagram prepared in Examples 1 to 5;

[0028] Fig.11 The Michaelis-Menten plot of steady-state kinetic analysis of the multi-component metal sulfide material prepared in Example 1: the amount of TMB changes when the H2O2 concentration is 2.5 mM;

[0029] Fig.12 Double reciprocal Lineweaver-Burk plot of steady-state kinetic analysis of the multi-component metal sulfide material prepared in Example 1: when the H2O2 concentration is 2.5 mM, the amount of TMB changes;

[0030] Fig.13The Michaelis-Menten plot of steady-state kinetic analysis of the multi-component metal sulfide material prepared in Example 1: the TMB concentration is constant at 0.1 mM, and the amount of H2O2 varies;

[0031] Fig.14 Double reciprocal Lineweaver-Burk plot of steady-state kinetic analysis of the multi-component metal sulfide material prepared in Example 1: TMB concentration is constant at 0.1 mM, and the amount of H2O2 varies;

[0032] Fig.15 The linear curve diagram of H2O2 detected by the multi-component metal sulfide material prepared in Example 1;

[0033] Fig.16 Selectivity diagram for detecting H2O2 for the multi-component metal sulfide material prepared in Example 1. DETAILED DESCRIPTION

[0034] The following examples are used to verify the beneficial effects of the present invention:

[0035] Example 1: The preparation method of the multi-component metal sulfide enzyme-mimicking material of this example is carried out according to the following steps:

[0036] 1. Preparation of polyoxometalate (FeMo6) precursor: Dissolve 1.2g of iron (III) sulfate in 20mL of water to obtain an iron sulfate solution; Add 5.3g of ammonium molybdate to 80mL of water at room temperature, stir and heat to boiling, slowly add the iron sulfate solution, react for 12 hours under boiling conditions, keep the solution pH value between 2.5 and 3.0 during the reaction, filter out block crystals after the reaction, and then recrystallize the block crystals twice in hot water at 80°C to obtain a polyoxometalate (FeMo6) precursor;

[0037] 2. Preparation of multi-component metal sulfide enzyme-mimicking materials: Under ultrasonic conditions, disperse 50 mg of the polyoxometalate (FeMo6) precursor prepared in step 1 and 100 mg of thiourea into 25 mL of deionized water, and then transfer the solution to a 50 mL Teflon-lined autoclave for hydrothermal reaction at 200 °C for 12 hours; then filter the product and wash it with ethanol and water three times, and then place it in a vacuum drying oven at 60 °C for 24 hours to obtain a multi-component metal sulfide enzyme-mimicking material.

[0038] The multi-component metal sulfide enzyme-mimicking material prepared in Example 1 was subjected to an X-ray diffraction test, and the obtained PXRD spectrum was as follows: Figure 1 As shown, from Figure 1It can be seen that the diffraction peaks at 14.4°, 32.6° and 58.3° correspond to the (002), (101) and (110) crystal planes of MoS2. In addition, the diffraction peaks at 28.7°, 33.0° and 56.7° are attributed to the (111), (200) and (311) crystal planes of FeS2, respectively. This indicates that the multi-component metal sulfide enzyme-mimicking material is composed of MoS2 and FeS2, and the material is successfully prepared.

[0039] The Raman spectrum of the multi-component metal sulfide enzyme-mimicking material prepared in Example 1 is shown in FIG. Figure 2 As shown, from Figure 2 It can be seen that in multi-component metal sulfides, MoS2 exists as a mixed phase of 1T-MoS2 and 2H-MoS2.

[0040] The X-ray photoelectron spectrum of the multi-component metal sulfide enzyme-mimicking material prepared in Example 1 is as follows: Figure 3 As shown, a is the XPS spectrum of Mo element, b is the spectrum of S element, from Figure 3 It can be seen from a that Mo in 1T-MoS2 4+ 3d5 / 2 and Mo 4+ The binding energies of 3d5 / 2 are 228.8eV and 232.0eV respectively. 4+ 3d5 / 2 and Mo 4+ The binding energies of 3d5 / 2 are 229.6eV and 232.8eV respectively. The binding energies of 230.6eV and 233.7eV are characteristic of defects in the basal plane / edge of MoS2. The binding energy of 236.0eV is caused by insufficient synthesis of MoO3 during the hydrothermal process. The binding energy of 226.0eV corresponds to S2s. Figure 3 It can be seen from b that the binding energies of 161.7 eV and 162.9 eV are similar to those of S in 1T-MoS2. 2- The binding energies of 162.2eV and 163.3eV indicate that S 2- Existing in 2H-MoS2. The binding energies of 162.8eV and 164.3eV correspond to S2 2- , the binding energies of 161.0 eV and 169.1 eV correspond to SCN - and SO4 4- .

[0041] The microscopic morphology of the multi-component metal sulfide material prepared in Example 1 is as follows Figure 4 As shown, a is a scanning electron microscope photo, b is a transmission electron microscope photo, and c and d are high-resolution transmission electron microscope photos. Figure 4It can be seen that the multi-component metal sulfide material is composed of flower-shaped nanosheets with a diameter of about 2 μm. The high-resolution transmission electron microscopy image shows that the sample contains 1T MoS2, 2H MoS2, FeS2 and defects.

[0042] Example 2: This example is different from Example 1 in that the time of the hydrothermal reaction in step 2 is 8 hours, and the other steps and parameters are the same as those in Example 1.

[0043] Example 3: This example is different from Example 1 in that the time of the hydrothermal reaction in step 2 is 18 hours, and the other steps and parameters are the same as those in Example 1.

[0044] Example 4: This example is different from Example 1 in that the time of the hydrothermal reaction in step 2 is 24 hours, and the other steps and parameters are the same as those in Example 1.

[0045] Example 5: This example is different from Example 1 in that the time of the hydrothermal reaction in step 2 is 36 hours, and the other steps and parameters are the same as those in Example 1.

[0046] Comparative Example 1: This comparative example is to prepare MoS2. The specific steps are as follows: weigh 50 mg of H3PMo 12 O 40 ·12H2O, 100mg thiourea, add 30mL deionized water, transfer to a 50mL reactor after ultrasonic treatment for 1h, and react at 200℃ for 24h. After cooling to room temperature, wash with deionized water and ethanol three times, and dry in a vacuum oven at 80℃ for 12h to obtain a black MoS2 powder sample.

[0047] The peroxidase-like activity of the multi-component metal sulfide materials prepared in Examples 1 to 5 and the MoS2 prepared in Comparative Example 1 was evaluated by catalyzing the reaction of TMB with H2O2. The specific operation was as follows: the concentration of FeS2-MoS2 was 35 μg mL -1 Or the concentration of MoS2 is 35 μg mL -1 , TMB concentration of 2mmol / L, H2O2 concentration of 5mmol / L, added to 0.2mol / L acetate buffer solution (pH 4.0), incubated at room temperature for 5min. The absorbance of the solution at 652nm was measured by UV-visible spectrophotometry. The activity graph of the multi-component metal sulfide material FeS2-MoS2 of Example 1 and the MoS2 prepared in Comparative Example 1 is shown in Fig. Figure 5 As shown, from Figure 5It can be seen that, except for the control experiment (TMB and H2O2), all materials exhibit peroxidase-like activity. The peroxidase-like activity of FeS2-MoS2 prepared in Example 1 is higher than that of MoS2, and its relative activity is 3.01 times that of MoS2. The calculated specific activities (SA) of the multi-component metal sulfide materials prepared in Examples 1 to 5 are shown in Figure 2. Figure 6 As shown, from Figure 6 It can be seen that the SA of the multi-component metal sulfide material FeS2-MoS2 prepared in Example 1 is about 1.69 U / mg, which is higher than the SA of FeS2-MoS2 prepared in Examples 2 to 5 under the conditions of 8, 18, 24 and 36 hours.

[0048] The PXRD spectra of the multi-component metal sulfide materials prepared in Examples 1 to 5 are as follows: Figure 7 As shown, Figure 7 It was shown that the precursor was completely converted into FeS2 and MoS2 within 12 h.

[0049] The specific surface area of ​​the multi-component metal sulfide materials prepared in Examples 1 to 5 is shown in FIG. Figure 8 As shown, Figure 8 It shows that the specific surface areas of FeS2-MoS2 prepared under the conditions of 8, 12, 18, 24 and 36 h are 4.9, 9.8, 9.0, 8.8 and 8.5 cm, respectively. 3 g -1 Among them, the FeS2-MoS2 prepared in Example 1 has the largest specific surface area.

[0050] XPS test was performed on the Mo element in the multi-component metal sulfide material FeS2-MoS2 prepared in Examples 1 to 5, and the spectrum was subjected to peak fitting processing. The obtained spectrum is as follows: Fig.10 As shown, the obtained 1T-MoS2, 2H-MoS2 and defect contents are listed in Fig.11 Among them, the FeS2-MoS2 prepared in Example 1 has the highest 1T-MoS2 content and the most defects. The results show that as the reaction time increases, the content of 1T-MoS2 gradually increases, reaching a maximum value at 12 hours, and then as the reaction time increases, the content of 1T-MoS2 gradually decreases, while the content of 2H-MoS2 gradually increases. Therefore, the high content of defects and 1T-MoS2, as well as the large specific surface area, increase the active sites of the reaction, thereby improving the catalytic activity.

[0051] The steady-state kinetic analysis of the multi-component metal sulfide enzyme-mimicking material prepared in Example 1 was performed. Fig.11 Michaelis-Menten plot of the multi-component metal sulfide material prepared in Example 1: changing TMB concentration at a constant H2O2 concentration of 2.5 mM; Fig.12Double reciprocal Lineweaver-Burk plot of the multi-component metal sulfide material prepared in Example 1: changing TMB concentration at a constant H2O2 concentration of 2.5 mM; Fig.13 Michaelis-Menten plot of the multi-component metal sulfide material prepared in Example 1: changing the H2O2 concentration at a constant TMB concentration of 0.1 mM; Fig.14 Double reciprocal Lineweaver-Burk plot of the multi-component metal sulfide material prepared in Example 1: changing the H2O2 concentration while keeping the TMB concentration at 0.1 mM. Fig.11 and Fig.13 The Michaelis-Menten diagram describes the relationship between the reaction rate and the substrate H2O2 or TMB. The double reciprocal Lineweaver-Burk diagram is used to determine the values ​​of Km and Vmax, such as Fig.12 and Fig.14 As shown. The Km value of FeS2-MoS2 for H2O2 is 0.0336mM, and the Vmax value is 4.5510 -8 Ms -1 The Km value of FeS2-MoS2 for TMB is 0.388mM, and the Vmax value is 22.910 -8 Ms -1 .

[0052] The multi-component metal sulfide enzyme mimicking material prepared in Example 1 was subjected to H2O2 colorimetric detection. FeS2-MoS2 (20 μg mL-1), TMB (2 mM) and H2O2 of appropriate concentration were placed in a centrifuge tube, and the total reaction volume was supplemented with buffer (pH 4.0) to 2 mL. The reaction solution was fully mixed and reacted at 35°C for 5 min. The absorbance value at 652 nm was recorded. Fig.15 It can be seen that in the range of H2O2 concentration of 1 to 80 μM, the increase in absorbance at 625 nm is directly related to the increase in H2O2 concentration, and the detection limit of H2O2 is 0.52 μM.

[0053] The selectivity of the multi-component metal sulfide enzyme-mimicking material prepared in Example 1 for detecting H2O2 was analyzed. Fig.16 It can be seen that under the same conditions of detecting H2O2, the influence of different interfering agents was detected, among which the interfering agent was Mg 2+ 、Al 3+ , Cl - , K + 、Na + NH4 + 、CO3 +When the concentration of the interfering agent is 50 times that of H2O2, the effect on H2O2 detection is almost negligible, indicating that the colorimetric sensor based on the FeS2-MoS2 system has a high selectivity for H2O2 detection.

[0054] The Anderson type polyoxometalates of the present invention are composed of transition metal oxygen clusters and are ideal precursors for the precise synthesis of MoS2-based bimetallic sulfides, which are attributed to their clear structure, nanometer size (less than 1nm), excellent solubility in water, and the fact that they can provide a stoichiometrically controllable bimetallic source. Adding FeS2 to MoS2 using a hydrothermal synthesis method can stabilize the structure of 1T-MoS2, the synergistic effect of the bimetallic, the high content of 1T-MoS2 and defects, and have a larger specific surface area, more active sites, peroxidase activity, and improve the catalytic activity of MoS2-based materials.

Claims

1. A multi-component metal sulfide enzyme-mimicking material, characterized in that: The chemical formula of this material is FeS2-MoS2.

2. A method for preparing a multi-component metal sulfide enzyme-mimicking material according to claim 1, characterized in that: The method proceeds as follows:

1. Preparation of polyoxometalate precursor: adding ammonium molybdate to water at room temperature, stirring and heating to boiling, then adding iron (III) sulfate solution, reacting under boiling conditions for 10 to 12 hours, maintaining the pH value of the solution between 2.5 and 3.0 during the reaction, filtering out block crystals after the reaction, and recrystallizing in hot water to obtain polyoxometalate FeMo6 precursor; 2. Preparation of multi-component metal sulfide enzyme-mimicking materials: Under ultrasonic conditions, disperse the polyoxometalate FeMo6 precursor and thiourea in deionized water, mix them evenly and transfer them to a Teflon-lined autoclave, and keep them at a temperature of 180-220°C for 8-36 hours; filter the product and wash it with ethanol and water, and then dry it under vacuum to obtain a multi-component metal sulfide enzyme-mimicking material.

3. The method for preparing a multi-component metal sulfide enzyme-mimicking material according to claim 2, characterized in that: The concentration of the ferric sulfate solution described in step 1 is 0.05-0.07 g / mL.

4. The method for preparing a multi-component metal sulfide enzyme-mimicking material according to claim 2 or 3, characterized in that: The molar concentration of ammonium molybdate described in step 1 is 0.05-0.06 mmol / mL.

5. The method for preparing a multi-component metal sulfide enzyme-mimicking material according to claim 2 or 3, characterized in that: The molar ratio of iron sulfide to ammonium molybdate described in step 1 is 1:(1.4-1.5).

6. The method for preparing a multi-component metal sulfide enzyme-mimicking material according to claim 2 or 3, characterized in that: The temperature of the hot water described in step 1 is 75-85°C.

7. The method for preparing a multi-component metal sulfide enzyme-mimicking material according to claim 2 or 3, characterized in that: The mass ratio of the polyoxometalate precursor to thiourea in step 2 is 1:(1.5-2.5).

8. The method for preparing a multi-component metal sulfide enzyme-mimicking material according to claim 2 or 3, characterized in that: The concentration of the polyoxometalate precursor in step 2 is 1.5-2.5 mg / mL.

9. The use of a multi-component metal sulfide enzyme-mimicking material according to claim 1, characterized in that: This application is to use a multi-component metal sulfide enzyme-mimicking material as a colorimetric detection catalyst to catalyze the color development reaction of 3,3'-dimethylbenzidine.

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