A PVA-nano copper composite material, its preparation method and application

Abstract

The present invention discloses a PVA-nano copper composite material, its preparation method and application, which relate to the detection of amino anthraquinone drugs. The method comprises the following steps: 1) Citric acid and histidine are uniformly mixed in proportion, deionized water is added and dissolved by ultrasonic to obtain a reaction solution, and the reaction is carried out at an oven temperature of 150-250 °C for 3-6 h to obtain histidine-functionalized graphene quantum dots; 2) Weigh PVA and add it to deionized water, stir and boil until completely dissolved to prepare a PVA solution; add the histidine-functionalized graphene quantum dots to the PVA solution; adjust the pH to neutral with NaOH, and dropwise add a copper chloride solution under stirring; stir for 80-120 min, add 3% borax to make the mixture into a gel, and freeze-dry; 3) The freeze-dried gel is calcined in an inert gas atmosphere to obtain a PVA-nano copper composite material. The PVA-nano copper composite material is used for detecting amino anthraquinone, and the detection limit is as low as 3×10<supgt;−9< / supgt; mol / L, with high sensitivity.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrochemical sensing, relates to the detection of aminoanthraquinone drugs, and particularly relates to a PVA-nano copper composite material, a preparation method thereof, and an application thereof in the detection of aminoanthraquinone. Background Art

[0002] Aminoanthraquinone compounds, as intermediates for various drugs, have certain toxicity. 1-Aminoanthraquinone is an organic compound with slight toxicity. On October 27, 2017, the World Health Organization's International Agency for Research on Cancer (IARC) released a preliminary list of carcinogens, and 2-aminoanthraquinone was included in the list of Group 3 carcinogens. Generally, the determination methods of aminoanthraquinone drugs are mainly based on HPLC analysis. However, it requires expensive instruments, time-consuming extraction or preconcentration steps, and skilled operators. Electrochemical methods overcome these difficulties and have become the preferred method due to their inherent advantages such as low instrument and operation costs, simple operation, and on-site monitoring.

[0003] Polyvinyl alcohol (PVA) is a polymer with high visible light transparency and non-toxicity, and has broad potential application prospects in the fields of optics, medicine, healthcare, membranes, etc. Hydrogel is a polymer network that can absorb a large amount of water. Physically cross-linked PVA hydrogel is a good model because it has a single relaxation time of physical bonds due to secondary hydrogen interactions. The rheological properties and kinetics of physical PVA gels are well-known.

[0004] In recent years, metal nanoparticles (MNPs) have received increasing attention due to their versatile physical and chemical properties. Compared with their bulk metal forms, they have many new characteristics such as optics, catalysis, and antibacterial properties. Among them, copper nanoparticles (CuNPs) have good thermal conductivity, electrical conductivity, anti-wear properties, and antibacterial properties, and thus have many practical applications in heat exchangers, conductive copper wires in inkjet printing, anti-wear additives in lubricants, and antibacterial agents. Currently known methods for preparing CuNPs include hydrothermal reduction method, supercritical water technology, microemulsion technology, sonochemical reduction method, laser ablation technology, metal vapor synthesis method, vacuum vapor deposition, aqueous solution reduction method, biological method, and radiation method.

[0005] Copper is an important material and has applications in catalysis, printed electronic circuits, and many other fields. However, due to the relatively low antioxidant property of CuNPs, its synthesis is more difficult compared to other noble metals. To avoid oxidation, reduction methods are usually carried out in an inert atmosphere, in an organic solvent and in the presence of a protective polymer. In addition, the nanoparticles are dispersed in the solvent, and van der Waals forces and Brownian motion have important effects on their stability, so it is necessary to prevent the aggregation of nanoparticles. Van der Waals interactions become important only at very short interparticle distances, while Brownian motion provides continuous nanoparticle collisions. The combination of these factors usually leads to the aggregation of nanoparticles. Polymers with functional groups that have an affinity for the metal surface protect and avoid cluster aggregation through steric stability. PVA hydrogel is a water-stable dispersion material containing many isolated hydroxyl functional groups that can adsorb metal ions and complex with metal ions, and PVA is a hydrophilic and environmentally friendly polymer. Based on this, PVA is selected as the matrix for stable dispersion to prepare stable CuNPs. Using PVA as the matrix for stable dispersion and graphene quantum dots as the bridge between the connecting matrix and nanoparticles, highly dispersed copper nanoparticles are synthesized and prepared for the electrochemical detection of aminoanthraquinone drugs. Summary of the Invention

[0006] Aiming at the above problems existing in the prior art, the first technical problem to be solved by the present invention is to provide a preparation method of a PVA-nano copper composite material; the second technical problem to be solved by the present invention is to provide the PVA-nano copper composite material prepared by this method; the third technical problem to be solved by the present invention is to provide the application of the PVA-nano copper composite material in the detection of aminoanthraquinone.

[0007] To solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0008] A preparation method of a PVA-nano copper composite material, comprising the following steps:

[0009] 1) Weigh citric acid and histidine in proportion and mix them evenly, add deionized water and then carry out ultrasonic dissolution to obtain a reaction solution. Put the reaction solution into an oven and react for 3-6 h under the condition that the oven temperature is 150-250 °C to obtain histidine-functionalized graphene quantum dots;

[0010] 2) Weigh PVA and add it to deionized water, stir and boil until completely dissolved to make a PVA solution; add the histidine-functionalized graphene quantum dots prepared in step 1) to the PVA solution; adjust the pH to neutral with NaOH, and gradually add copper chloride solution dropwise with stirring; stir for 80 - 120 min, add 3% borax to make the solution gel, and freeze-dry it; the mass ratio of PVA, histidine-functionalized graphene quantum dots, copper chloride, and borax is 1∶0.05∶0.02 - 0.04∶0.075 - 0.15;

[0011] 3) Calcinate the gel freeze-dried in step 2) in an inert gas atmosphere to obtain a PVA-nano copper composite material.

[0012] Furthermore, in step 1), the molar ratio of citric acid to histidine is 1∶1 - 1∶0.5.

[0013] Furthermore, in step 1), the reaction is carried out at an oven temperature of 180 - 200 °C for 4 h.

[0014] Furthermore, in step 2), the dissolution temperature is 80 - 100 °C.

[0015] Furthermore, in step 2), the concentration of the PVA solution is 3 - 9 wt%.

[0016] Furthermore, in step 3), the calcination temperature is 600 - 900 °C, and the calcination time is 4 - 10 h.

[0017] Preferably, in step 3), the calcination temperature is 700 - 800 °C, and the calcination time is 3 - 7 h.

[0018] The PVA-nano copper composite material prepared by the above method.

[0019] The application of the described PVA-nano copper composite material in the preparation of a PVA / CuNPs / GCE composite electrode.

[0020] The application of the described PVA-nano copper composite material in the detection of aminoanthraquinone. Disperse the prepared PVA-nano copper composite material in deionized water, and mix it with a 1 wt% chitosan solution in a volume ratio of 1∶1 - 5∶1 to modify it on a glassy carbon electrode to prepare a PVA / CuNPs / GCE electrode;

[0021] Disperse different standard concentrations of aminoanthraquinone in PBS solution, use the PVA / CuNPs / GCE electrode as the working electrode, and perform cyclic voltammetry measurement using a three-electrode system to obtain the current values of different standard concentrations of aminoanthraquinone;

[0022] Based on the obtained photocurrent values I of different standard concentrations of aminoanthraquinone and the photocurrent value I0 of the sample with an aminoanthraquinone concentration of 0, the corresponding photocurrent difference I - I0 for different standard concentrations is calculated; then a linear equation is constructed using the aminoanthraquinone concentrations of different standard concentrations and the corresponding current differences.

[0023] The photocurrent value of the measured sample to be tested is substituted into the linear equation to obtain the concentration of aminoanthraquinone in the sample to be tested.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1) Compared with traditional materials, the PVA-nano copper composite material prepared by this method has good biocompatibility.

[0026] 2) Compared with inorganic nanoparticles and metal semiconductor quantum dots, the PVA-nano copper composite material prepared by this method will not migrate to cause harm to the human body and has better safety.

[0027] 3) Using the PVA-nano copper composite material prepared by this method to detect aminoanthraquinone has a low detection limit and high sensitivity. Description of the Drawings

[0028] Figure 1 It is a scanning electron micrograph of the PVA-nano copper composite material prepared in Example 1.

[0029] Figure 2 It is an XRD pattern of the PVA-nano copper composite material prepared in Example 1.

[0030] Figure 3 It is a linear graph for detecting 2-aminoanthraquinone using the PVA-nano copper composite material prepared in Example 1.

[0031] Figure 4 It is a differential pulse voltammogram in the absence and presence of 2-aminoanthraquinone. In the figure, a is the PBS solution and b is the PBS solution containing 2-aminoanthraquinone. Detailed Embodiments

[0032] The present invention will be further described below in conjunction with specific embodiments.

[0033] Example 1

[0034] 1) Preparation of histidine-functionalized graphene quantum dots His-GQD: Raw materials are taken according to the molar ratio of citric acid:histidine of 1:1, and the two are mixed evenly, and water is added until dissolved. Using the high-temperature pyrolysis method, the reaction is carried out in an oven at 180 °C for 4 h to prepare histidine-functionalized graphene quantum dots His-GQD.

[0035] 2) Preparation of PVA-nanocopper (PVA / CuNPs) composite material: Weigh PVA and add it to deionized water, stir and boil until it is completely dissolved to make a PVA solution; the dissolution temperature is 80-100 °C. Disperse His-GQD in PVA and adjust the pH of the solution to 7.0; then, under continuous stirring, add copper chloride solution to the solution, stir for 2 hours, and drop 3% borax into the mixed solution. The mass ratio of PVA, histidine-functionalized graphene quantum dots His-GQD, copper chloride, and borax is 1:0.05:0.02:0.075; make the mixed solution into a gel, freeze-dry the gel, and calcine it at 700 °C for 7 hours in a nitrogen atmosphere to obtain the PVA-nanocopper composite material. Its scanning diagram is as shown in Figure 1 , and the XRD diagram is as shown in Figure 2 .

[0036] Preparation of PVA / CuNPs modified GCE electrode (PVA / CuNPs / GCE electrode): Weigh the prepared PVA / CuNPs composite material and add it to deionized water, and ultrasonically obtain a suspension of 1.0 mg / mL, which is mixed with a 1 wt% chitosan solution at a volume ratio of 1:1; drop 10 μL of the mixed solution of PVA / CuNPs and 1 wt% chitosan solution on the surface of the pre-cleaned GCE electrode, and dry it at 40 °C for standby.

[0037] Prepare a series of concentrations (0.003, 0.006, 0.01, 0.03, 0.06, 0.1, 0.3, 0.6, 1, 2, 4, 6, 8, 10, 20, 40, 60, 80, 100, 200, 400 μM) of 2-aminoanthraquinone with PBS at pH = 7.0. Using a three-electrode system, with the PVA / CuNPs / GCE electrode as the working electrode, Ag / AgCl as the reference electrode, and a platinum wire as the counter electrode, perform differential pulse voltammetric current measurement at a voltage of 0-1.2 V. The current values I of different known concentrations of aminoanthraquinone drugs obtained, and the current value I0 of the sample with aminoanthraquinone drugs being 0 are used to calculate the corresponding photocurrent difference I - I0 at different concentrations; then, a linear model is constructed using different known concentrations of aminoanthraquinone drugs and the corresponding current differences. The obtained results are as shown in Figure 3 . The linear range is 1×10 -8 -4×10 -4 mol / L, and the detection limit is 3×10 -9 mol / L.

[0038] Dissolve 2-aminoanthraquinone in PBS with pH = 7.0 to prepare a 0.4 M solution. Using a three-electrode system, with the PVA / CuNPs / GCE electrode as the working electrode, Ag / AgCl as the reference electrode, and a platinum wire as the counter electrode, differential pulse voltammetry measurements were performed on PBS and the 2-aminoanthraquinone PBS solution at voltages from 0 to 1.2 V ( Figure 4 ).

[0039] Example 2

[0040] 1) Preparation of histidine-functionalized graphene quantum dots His-GQD: Take raw materials according to the molar ratio of citric acid to histidine of 1:0.8, mix them evenly, add water until dissolved, and use the high-temperature pyrolysis method to react in an oven at 180 °C for 4 h to obtain histidine-functionalized graphene quantum dots His-GQD.

[0041] 2) Preparation of PVA-nanocopper (PVA / CuNPs) composite material: Weigh PVA and add it to deionized water, stir and boil until completely dissolved to make a PVA solution; the dissolution temperature is 80 - 100 °C. Disperse His-GQD in PVA and adjust the pH of the solution to 6.8; then, under continuous stirring, add a copper chloride solution to the solution, stir for 2 hours, and add 3% borax to the mixed solution; the mass ratio of PVA, histidine-functionalized graphene quantum dots His-GQD, copper chloride, and borax is 1:0.05:0.03:0.10; make the mixed solution into a gel, freeze-dry the gel, and calcine it at 800 °C for 5 hours in a nitrogen atmosphere to obtain the PVA-nanocopper composite material.

[0042] Preparation of PVA / CuNPs-modified GCE electrode (PVA / CuNPs / GCE electrode): Weigh the prepared PVA / CuNPs powder and add it to deionized water, sonicate to obtain a 1.0 mg / mL suspension, and mix it with a 1 wt% chitosan solution in a volume ratio of 2:1; drop 10 μL of the mixed solution of PVA / CuNPs and 1 wt% chitosan solution onto the surface of the pre-cleaned GCE electrode and dry it at 40 °C for later use.

[0043] 1-Aminoanthraquinone was formulated into a series of concentrations (0.01, 0.03, 0.06, 0.1, 0.3, 0.6, 1, 2, 4, 6, 8, 10, 20, 40, 60, 80, 100, 200, 400 μM) with PBS at pH = 7.0. Using a three-electrode system, with the PVA / CuNPs / GCE electrode as the working electrode, Ag / AgCl as the reference electrode, and a platinum wire as the counter electrode, differential pulse voltammetric current measurements were carried out at a voltage of 0 - 1.2V. The current values I of different known concentrations of aminoanthraquinone drugs and the current value I0 of the sample with aminoanthraquinone drugs being 0 were obtained, and the corresponding photocurrent difference I - I0 at different concentrations was calculated; then a linear model was constructed using different known concentrations of aminoanthraquinone drugs and the corresponding current differences.

[0044] Example 3

[0045] 1) Preparation of histidine-functionalized graphene quantum dots His-GQD: Raw materials were taken according to the molar ratio of citric acid:histidine of 1:0.5, and the two were mixed evenly, then water was added until dissolved. Using the high-temperature pyrolysis method, the reaction was carried out at 200 °C for 4 h in an oven to obtain histidine-functionalized graphene quantum dots His-GQD.

[0046] 2) Preparation of PVA-nano copper (PVA / CuNPs) composite material: Weigh PVA and add it to deionized water, stir and boil until completely dissolved to make a PVA solution; the dissolution temperature is 80 - 100 °C. Disperse His-GQD in PVA, and adjust the pH of the solution to 7.3; then, under continuous stirring, add copper chloride solution to the solution, stir for 80 min, and drop 3% borax into the mixed solution; the mass ratio of PVA, histidine-functionalized graphene quantum dots His-GQD, copper chloride, and borax is 1:0.05:0.04:0.15; make the mixed solution into a gel, freeze-dry the gel, and calcine it at 750 °C for 3 hours in a nitrogen atmosphere to obtain the PVA-nano copper composite material.

[0047] Preparation of PVA / CuNPs modified GCE electrode (PVA / CuNPs / GCE electrode): Weigh the prepared PVA / CuNPs powder and add it to deionized water, and ultrasonically obtain a suspension of 1.0 mg / mL; mix it with a 1 wt% chitosan solution at a volume ratio of 5:1; drop 10 μL of the mixed solution of PVA / CuNPs and 1 wt% chitosan solution on the surface of the pre-cleaned GCE electrode, and dry it at 40 °C for standby.

[0048] 2-Aminoanthraquinone was prepared into a series of concentrations (0.01, 0.03, 0.06, 0.1, 0.3, 0.6, 1, 2, 4, 6, 8, 10, 20, 40, 60, 80, 100, 200, 400 μM) with PBS at pH = 7.0. Using a three-electrode system, with the PVA / CuNPs / GCE electrode as the working electrode, Ag / AgCl as the reference electrode, and a platinum wire as the counter electrode, differential pulse voltammetry was carried out at a voltage of 0 - 1.2 V. The current values I of different known concentrations of aminoanthraquinone drugs and the current value I0 of the sample with aminoanthraquinone drugs at 0 were obtained, and the corresponding photocurrent differences I - I0 at different concentrations were calculated; then a linear model was constructed using different known concentrations of aminoanthraquinone drugs and the corresponding current differences.

Claims

1. A preparation method of a PVA-nano copper composite material, characterized in that, It includes the following steps: 1) Weigh citric acid and histidine proportionally and mix them evenly. After adding deionized water, perform ultrasonic dissolution to obtain a reaction solution. Place the reaction solution in an oven and react it for 3 - 6 h under the condition that the oven temperature is 150 - 250 °C to obtain histidine-functionalized graphene quantum dots; the molar ratio of citric acid to histidine is 1:1 - 1:0.5; 2) Weigh PVA and add it to deionized water, stir and boil until completely dissolved to make a PVA solution; add the histidine-functionalized graphene quantum dots prepared in step 1) to the PVA solution; adjust the pH to neutral with NaOH, and dropwise add a copper chloride solution while stirring; stir for 80 - 120 min, add 3% borax to make the solution into a gel, and freeze-dry; The mass ratio of PVA, histidine-functionalized graphene quantum dots, copper chloride, and borax is 1:0.05:0.02 - 0.04:0.075 - 0.15; the dissolution temperature is 80 - 100 °C; the concentration of the PVA solution is 3 - 9 wt%; 3) Calcinate the gel freeze-dried in step 2) in an inert gas atmosphere to obtain a PVA-nano copper composite material; the calcination temperature is 600 - 900 °C, and the calcination time is 4 - 10 h.

2. The PVA-nano copper composite material prepared by the method described in claim 1.

3. The application of the PVA-nano copper composite material described in claim 2 in the preparation of a PVA / CuNPs / GCE composite electrode.

4. The application of the PVA-nano copper composite material described in claim 2 in the detection of aminoanthraquinone.

5. The application according to claim 4, characterized in that Disperse the prepared PVA-nano copper composite material in deionized water, mix it with a 1 wt% chitosan solution at a volume ratio of 1:1 - 5:1, and modify it on a glassy carbon electrode to prepare a PVA / CuNPs / GCE electrode; Disperse different standard concentrations of aminoanthraquinone in a PBS solution, use the PVA / CuNPs / GCE electrode as the working electrode, and perform cyclic voltammetry measurement using a three-electrode system to obtain the current values of different standard concentrations of aminoanthraquinone; Based on the obtained photocurrent values I of different standard concentrations of aminoanthraquinone and the photocurrent value I0 of the sample with an aminoanthraquinone concentration of 0, calculate the corresponding photocurrent difference I - I0 of different standard concentrations; then use the concentrations of different standard concentrations of aminoanthraquinone and the corresponding current differences to construct a linear equation; Substitute the measured photocurrent value of the sample to be measured into the linear equation to obtain the concentration of aminoanthraquinone in the sample to be measured.

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