Preparation method of CsCu2I3 nano-enzyme with high peroxide activity

Abstract

The invention relates to a preparation method of CsCu2I3 nano enzyme with high peroxide activity, which belongs to the technical field of inorganic nano enzyme material preparation, and comprises the following steps: adding cesium iodide and cuprous iodide into deionized water, grinding until the cesium iodide and the cuprous iodide are uniformly mixed, then adding oleic acid and oleylamine, adding a mixed solution of n-hexane and ethanol, and continuously grinding until the cesium iodide and the cuprous iodide are uniformly mixed; and transferring the ground sample into a round-bottom flask, adding an n-hexane solution of DOPC and DOPC-Cl, gradually removing n-hexane in a nitrogen atmosphere, carrying out heat treatment in a vacuum drying oven at 100-130 DEG C for 8 hours, cooling to 25 DEG C at a constant rate of 5 DEG C / h, adding deionized water, and carrying out ultrasonic treatment for 1 minute to obtain the high peroxide activity CsCu2I3 nano-enzyme. According to the method, the PM-CsCu2I3NCs with high peroxide catalytic activity is prepared through solid-phase grinding for the first time, the method is simple, operation is easy, energy consumption is small, and the product has high peroxide catalytic activity.

Description

Technical Field

[0001] The invention belongs to the technical field of inorganic nanozyme material preparation, and specifically relates to a new method for preparing CsCu2I3 inorganic nanozyme with high peroxide catalytic activity. Background Art

[0002] Biological enzymes are environmentally friendly biomaterials produced by living cells with significant catalytic efficiency and excellent substrate specificity. They play an important role in the physiological metabolism of living organisms and modern synthetic industries. However, the complex preparation process, unstable catalytic activity, short half-life and inherent environmental sensitivity limit the large-scale utilization of natural enzymes. Existing nanozymes are generally divided into two categories: oxidoreductase family and hydrolase family. Although nanozymes cover a wide range, current research mainly focuses on catalase (CAT), peroxidase (POD), superoxide dismutase (SOD) and oxidase (OXD) redox nanozymes. Perovskite nanoparticles CsPbX3 NCs (X = Cl-, Br-, I-) and non-lead perovskite nanocrystals Cs-M-XNCs (Cs = Cs, Rb; M = Cu, Ag, Fe, Co, Pt, Csu, Pd, etc.; X = Cl-, Br-, I-) are emerging functional nanoparticles. They are a class of inorganic nanocrystalline materials composed of metal ions and halogen ions. In view of this, researchers expect to apply the excellent optical properties of CsPbX3 NCs in the biological field and show their great potential. At present, CsPbX3 NCs have been proven to have enzyme-like activity and have become a class of highly promising inorganic nanozymes. It is gratifying that CsPbX3 NCs have achieved remarkable results in the fields of fluorescent bio-ink, antibacterial, DNA probes, real-time in vitro detection of glioma cells, biological metabolic analysis, biological imaging, drug loading and delivery, and have shown broad prospects for biological development. It is worth noting that the phospholipid membrane-coated CsPbX3 NCs have biocatalytic activity. Unlike other peroxidase nanozymes that rely on additional colorimetric reagents, PM-CsPbX3 NCs can be used as self-reporting nanoprobes. By modifying different oxidases on the ligand membrane of CsPbX3 NCs, the detection of uric acid, glucose, lactic acid, cholesterol and many other substances can also be achieved. The researchers used SiO2 as a protective shell, which not only well protected the CsPbBr3 NCs, but also improved their biocompatibility. Under X-ray excitation at a voltage of 50 k V, the green fluorescent CsPbBr3@SiO2 and the orange fluorescent CsPbBr 1.5 I 1.5 @SiO2 and red fluorescent CsPbBr 1.2 I 1.8@SiO2 mice in vivo imaging is clearly visible. The preparation method of the material determines the properties of the material, so the method of efficiently preparing excellent perovskite nanozymes is particularly important.

[0003] The synthesis of inorganic perovskite nanozymes mainly includes high-temperature injection method, anti-solvent method, etc. For example, Shen et al. prepared by high-temperature injection method, mixed 0.4g Cs2CO3, 15ml ODE (octadecene) and 1.2ml OA (oleic acid) in a 100ml three-necked flask and stirred, dried at 120℃ under argon for 30 minutes, and then heated at 150℃ under argon for at least 30 minutes. 0.188mmol PbX2 and 5ml ODE were degassed in another 100ml three-necked flask to synthesize CsPbX3 NCs, and the reaction mixture was cooled in an ice-water bath for 5s. When the solution temperature of CsPbX3 NCs dropped to room temperature, CsX and OB (oleylamine) were then added to the CsPbX3 NCs solution to synthesize the Cs4PbX6 shell. Li et al. prepared a series of CsCu2X3 NCs at room temperature by the antisolvent method. CsCl and CuCl were dissolved in DMSO (dimethyl sulfoxide) to form a precursor solution. 200 μL of the precursor solution was injected into 5 mL of toluene, and the supernatant was discarded after centrifugation. Different amounts of oleic acid were added to 5 mL of toluene to form an antisolvent, and oleic acid-capped CsCu2Cl3 NCs were synthesized.

[0004] The experimental method for synthesizing inorganic perovskite nanozymes has complicated experimental operation procedures. At the same time, the reaction requires the participation of organic reagents (such as ODE, DMSO, toluene) and harsh high temperature (120°C, 150°C) reaction conditions, which often lead to changes in the valence state of metal ions. In addition, the reaction is time-consuming and energy-consuming, which is not conducive to large-scale production, limiting its application in fields such as peroxide catalytic activity, and further improvement and innovation are needed. In summary, at this stage, there is a lack of a method for synthesizing inorganic perovskite nanozymes that is green, environmentally friendly and can be quickly synthesized at room temperature to help further explore its application in fields such as biochemical analysis.

[0005] Therefore, it is necessary to propose a new synthesis method that can be carried out at room temperature, is green and pollution-free, and does not require the participation of organic solvents. The prepared CsCu2I3 nanozyme has excellent water stability and biological nanozyme catalytic activity. This synthesis method is of great significance for the large-scale production and application of inorganic perovskites. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the problems existing in the background technology and provide a new method for synthesizing CsCu2I3 perovskite in large quantities at room temperature and pressure, which is simple to operate, short in time, green and environmentally friendly.

[0007] The technical problem of the present invention is solved by the following technical solutions:

[0008] A method for preparing a CsCu2I3 nanozyme with high peroxide activity, firstly taking cesium iodide and cuprous iodide in a molar ratio of 1:2 into a mortar and adding deionized water for grinding, the mixture gradually becomes dense from fluffy powder, and grinding is continued until the mixture is evenly mixed and then the grinding is stopped, the product emits yellow light under ultraviolet fluorescence irradiation at a wavelength of 254nm, then adding oleic acid and oleylamine in a volume ratio of 5:1, and adding a mixed solution of n-hexane and ethanol in a volume ratio of 2:1 and continuing to grind until uniform, wherein 0.2mL of deionized water, 150μL of oleic acid, 30μL of oleylamine and 0.5-2ml of a mixed solution of n-hexane and ethanol are used for every 1mmol of cesium iodide;

[0009] The ground sample was transferred to a round-bottom flask, and the mixture of DOPC and DOPC-Cl was ultrasonically dispersed in n-hexane and then added to the round-bottom flask. Then, the n-hexane was gradually removed in a nitrogen atmosphere, and a uniform yellow film was observed to be formed at the bottom of the round-bottom flask by fluorescence irradiation at a wavelength of 254 nm. After being heat-treated at 100-130° C. for 8 h in a vacuum drying oven, it was cooled to 25° C. at a constant rate of 5° C. / h, and deionized water was added for ultrasonic treatment for 1 min to form a stable DOPC-wrapped CsCu2I3 NCs nano solution, thereby obtaining a CsCu2I3 nanozyme with high peroxide activity; the DOPC is 1,2-dioleoyl-sn-glycero-3-phosphocholine, and the DOPC-Cl is the chloride salt of 1,2-dioleoyl-3-trimethylammonium propane, wherein 0.01 g of DOPC and 0.001-0.004 g of cesium iodide are used for every 1 mmol of cesium iodide. For DOPC-Cl, use 1 mL of deionized water during sonication after cooling.

[0010] In the preparation method of the high peroxide activity CsCu2I3 nanozyme of the present invention, in order to improve the stability of the product and make the grinding more complete, 1.5 mL of a mixed solution of n-hexane and ethanol is used for every 1 mmol of cesium iodide during the grinding process.

[0011] In the preparation method of the CsCu2I3 nanozyme with high peroxide activity of the present invention, in order to better improve the peroxide catalytic activity of the product, DOPC-Cl is added, and the preferred amount is 0.002 g DOPC-Cl per 1 mmol cesium iodide.

[0012] In the method for preparing a CsCu2I3 nanozyme with high peroxide activity of the present invention, in order to further improve the peroxide catalytic activity of the product, the temperature of the heat treatment in the vacuum drying oven is preferably 110°C.

[0013] Beneficial effects:

[0014] The present invention realizes the preparation of PM-CsCu2I3 NCs with high peroxide catalytic activity for the first time through solid phase grinding, and the peroxide catalytic activity is significantly enhanced through subsequent treatment, which provides a good prospect for the application of PM-CsCu2I3 NCs in biocatalytic activity.

[0015] In summary, the present invention has the advantages of simple method, easy operation, low energy consumption, and good stability of the synthesized PM-CsCu2I3 NCs inorganic perovskite in water, and is of great significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the solid XRD spectrum of the PM-CsCu2I3 NCs perovskite material prepared in Example 1.

[0017] Figure 2 It is the solid absorption spectrum and solid fluorescence emission spectrum of the PM-CsCu2I3 NCs perovskite material prepared in Example 1.

[0018] Figure 3 This is a photograph of the PM-CsCu2I3 NCs perovskite material prepared in Example 1 under irradiation with a 302nm ultraviolet lamp.

[0019] Figure 4 After adding PM-CsCu2I3 NCs and H2O2 (50mmol / L), the color of TMB indicator (4mmol / L) changed.

[0020] Figure 5 Steady-state kinetic analysis of PM-CsCu2I3 NCs: Double reciprocal curves at different H2O2 concentrations (4mmol / L TMB).

[0021] Figure 6 Steady-state kinetic analysis of PM-CsCu2I3 NCs: Double reciprocal curves at different TMB concentrations (50mmol / L H2O2). DETAILED DESCRIPTION

[0022] Embodiment 1:

[0023] 1mmol cesium iodide, 2mmol cuprous iodide and 0.2mL deionized water were put into a mortar and ground. The mixture gradually changed from fluffy powder to dense powder attached to the wall of the mortar. Grinding was continued until the mixture became fluffy and then stopped. At this time, it showed yellow light under ultraviolet light. 150μL oleic acid and 30μL oleylamine were taken with a pipette, and a total volume of 1.5ml of a mixed solution of n-hexane and ethanol (the volume ratio of n-hexane to ethanol was 2:1) was added. Grinding was continued for 10min until uniform. 0.01g DOPC and 0.002g DOPC-Cl were weighed and ultrasonically dispersed in 2ml of n-hexane. The uniformly dispersed DOPC and DOPC-Cl mixed solution was added to the flask. Then, the n-hexane was gradually removed in a nitrogen atmosphere for 15min, and a uniform yellow film was observed to form at the bottom of the round-bottom flask. After heat treatment at 110 °C for 8 h in a vacuum drying oven, it was slowly cooled to room temperature (25 °C) at a constant rate of 5 °C / h. After adding 1 ml of deionized water and ultrasonic treatment for 1 min, stable PM-CsCu2I3 NCs with high peroxidase activity (Vmax of 1.586×10 -8 (moL / (L·s), Km is 0.0136mmo / L). Figure 1 The XRD spectrum of PM-CsCu2I3 NCs inorganic perovskite was successfully prepared in this example, and the product was subjected to solid absorption analysis and fluorescence emission test. Figure 2 The photoluminescence image of the product under ultraviolet light is shown in Figure 3 The color change of PM-CsCu2I3 after adding TMB (4mmol / L) and H2O2 (50mmol / L) is shown in Figure 4 In order to evaluate the peroxidation activity of PM-CsCu2I3 NCs, the kinetic process of its enzymatic reaction was studied using the steady-state kinetic method ( Figure 5 , Figure 6 ), Vmax (representing the maximum initial reaction rate) and Km (representing the Michaelis constant) were obtained. The low Km value indicates that PM-CsCu2I3 NCs have a high affinity for H2O2 substrate.

[0024] Embodiment 2:

[0025] In Example 1, under the premise that other conditions remain unchanged, the product effect when the amount of a mixed solvent of n-hexane and ethanol added in a volume ratio of 2: 1 is 0.5 ml, 1 ml, 1.5 ml, and 2 ml respectively, is studied, and Km=0.0154mmoL / L, 0.0175mmoL / L, 0.0136mmoL / L, and 0.0164mmoL / L are obtained respectively, so the optimal mixed solvent amount is 1.5 ml.

[0026] Embodiment 3:

[0027] In Example 1, when other conditions remain unchanged, the product effects when the dosages of DOPC-Cl are 0.001g, 0.002g, 0.003g, and 0.004g are studied, and the Km of the products when the dosages of DOPC-Cl are different are measured to be 0.0152mmo / L, 0.0136mmo / L, 0.0169mmo / L, and 0.0178mmo / L, respectively. Therefore, the optimal amount of DOPC-Cl is 0.002g.

[0028] Embodiment 4:

[0029] In Example 1, the vacuum drying temperature was changed to 100°C, 110°C, 120°C, and 130°C, respectively, and other conditions remained unchanged. The Km of the products treated at different drying temperatures were measured to be 0.0159mmo / L, 0.0136mmo / L, 0.0175mmo / L, and 0.0198mmo / L, respectively. Therefore, the optimal vacuum drying temperature is 110°C.

[0030] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing a CsCu2I3 nanozyme with high peroxide activity, firstly, taking cesium iodide and cuprous iodide in a molar ratio of 1:2 into a mortar and adding deionized water for grinding, the mixture gradually becomes dense from fluffy powder, and grinding is continued until the mixture is evenly mixed and then the grinding is stopped, and the product emits yellow light under ultraviolet light at a wavelength of 254nm, and then oleic acid and oleylamine in a volume ratio of 5:1 are added, and a mixed solution of n-hexane and ethanol in a volume ratio of 2:1 is added and continued to grind until uniform, wherein 0.2mL deionized water, 150μL oleic acid, 30μL oleylamine and 0.5-2ml mixed solution of n-hexane and ethanol are used for every 1mmol of cesium iodide; The ground sample was transferred to a round-bottom flask, and the mixture of DOPC and DOPC-Cl was ultrasonically dispersed in n-hexane and then added to the round-bottom flask. Then, the n-hexane was gradually removed in a nitrogen atmosphere, and a uniform yellow film was observed to be formed at the bottom of the round-bottom flask by fluorescence irradiation at a wavelength of 254 nm. After being heat-treated at 100-130° C. for 8 h in a vacuum drying oven, it was cooled to 25° C. at a constant rate of 5° C. / h, and deionized water was added for ultrasonic treatment for 1 min to form a stable DOPC-wrapped CsCu2I3 NCs nano solution, thereby obtaining a CsCu2I3 nanozyme with high peroxide activity; the DOPC is 1,2-dioleoyl-sn-glycero-3-phosphocholine, and the DOPC-Cl is the chloride salt of 1,2-dioleoyl-3-trimethylammonium propane, wherein 0.01 g of DOPC and 0.001-0.004 g of cesium iodide are used for every 1 mmol of cesium iodide. For DOPC-Cl, use 1 mL of deionized water during sonication after cooling.

2. The method for preparing a CsCu2I3 nanozyme with high peroxide activity according to claim 1, characterized in that: During the grinding process, 1.5 mL of a mixed solution of n-hexane and ethanol was used for every 1 mmol of cesium iodide.

3. The method for preparing a CsCu2I3 nanozyme with high peroxide activity according to claim 1, characterized in that: 0.002 g of DOPC-Cl was used per 1 mmol of cesium iodide.

4. The method for preparing a CsCu2I3 nanozyme with high peroxide activity according to claim 1, characterized in that: The temperature of the heat treatment in the vacuum drying oven is preferably 110°C.

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