阅读说明：本技术 一种硼酸修饰的金属氧化物纳米阵列-mof复合材料、其制备方法及应用 (Boric acid modified metal oxide nano array-MOF composite material, and preparation method and application thereof ) 是由 丁永玲 孙华东 陈敏 齐美丽 王保群 葛颜慧 于 2020-04-30 设计创作，主要内容包括：本发明公开了一种硼酸修饰的金属氧化物纳米阵列-MOF复合材料、其制备方法及应用,属于纳米复合材料技术领域。本发明在碳布表面生长过渡金属氧化物纳米阵列,并以此为柔性基底原位生长MOF材料,最后引入硼酸基功能单体,所述不同种类、不同形貌的MOF材料以单分散形式均匀分布在金属氧化物纳米阵列表面。本发明的制备方法简单、条件温和、形貌可调、结构可控、组分分布均匀,保留了金属氧化物纳米阵列和MOF材料多孔框架结构的完整性,兼具了良好的导电性能、金属氧化物及MOF材料优异的电催化性能,同时,复合材料表面经硼酸功能基团的修饰,作为柔性自支撑电极材料,可特异性识别顺式二羟基的生物分子。(The invention discloses a boric acid modified metal oxide nano array-MOF composite material, a preparation method and application thereof, and belongs to the technical field of nano composite materials. According to the method, a transition metal oxide nano array is grown on the surface of carbon cloth, an MOF material is grown in situ on the surface of the carbon cloth as a flexible substrate, and finally a boric acid group functional monomer is introduced, wherein the MOF materials of different types and different morphologies are uniformly distributed on the surface of the metal oxide nano array in a monodispersion mode. The preparation method is simple, mild in condition, adjustable in morphology, controllable in structure and uniform in component distribution, reserves the integrity of the metal oxide nano array and the MOF material porous framework structure, has good conductivity and excellent electrocatalytic performance of the metal oxide and the MOF material, and meanwhile, the surface of the composite material is modified by boric acid functional groups to serve as a flexible self-supporting electrode material and can specifically recognize cis-dihydroxy biomolecules.)

1. A preparation method of a boric acid modified metal oxide nano array-MOF composite material is characterized by comprising the following steps:

(a) preparation of metal oxide nano-arrays: firstly, growing any one or two of copper, cobalt, nickel, iron, zinc and manganese on the surface of carbon cloth by combining a hydrothermal method, a solvothermal method and an electrochemical deposition method with carbonization treatment to form a single metal or double metal oxide nano array;

(b) preparing a MOF material modified metal oxide nano array: taking the metal oxide nano array obtained in the step (a) as a substrate, adding 5-20 parts by weight of surfactant, 20-200 parts by weight of organic ligand, 100-800 parts by weight of organic solvent and 5-20 parts by weight of metal salt, and growing an MOF material in situ to obtain a metal oxide nano array-MOF composite material;

(c) preparation of the boric acid modified metal oxide nano array-MOF composite material: modifying the material obtained in the step (b) by using a surface stabilizer, then immersing the modified material into a solution containing a boric acid group functional monomer for 3-10 hours, adding the composite material into a cross-linking agent solution or cross-linking agent saturated steam, and reacting for 3-20 hours to obtain the boric acid modified metal oxide nano array-MOF composite material.

2. The method of making a boronic acid modified metal oxide nanoarray-MOF composite according to claim 1, wherein in step b):

the surfactant is at least one of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, polyvinyl alcohol, triethylamine, triethyldiamine, polyethylene pyrrolidone, polyacrylamide, polypropylene imine, alkyl sodium sulfonate, sodium fatty acid, polyoxyethylene ether, sodium carboxylate, hexadecyl trimethyl ammonium bromide, polyethylene glycol, polyethylene oxide, P123 and F127;

preferably, the organic ligand is at least one of 2-aminoterephthalic acid, 2-hydroxyterephthalic acid, 2, 5-diaminoterephthalic acid, 2, 5-dihydroxyterephthalic acid, terephthalic acid, trimesic acid, 2-methylimidazole, benzimidazole, 2-nitroimidazole and 4-nitroimidazole;

preferably, the organic solvent is at least one of methanol, ethanol, water and DMF;

preferably, the metal salt is at least one of copper, cobalt, nickel, iron, zinc and manganese salts, and preferably, the metal salt is one of nitrate, acetate, sulfate and chlorate.

3. The method of making a boronic acid modified metal oxide nanoarray-MOF composite according to claim 1, wherein in step c):

the surface stabilizer is at least one of imidazole-2-formaldehyde, 2-aminoimidazole, 4-imidazole formaldehyde, 1-ethyl-1H-imidazole-2-formaldehyde and 1-methyl-1H-imidazole-2-formaldehyde;

preferably, the borate functional monomer is at least one of 2-aminobenzeneboronic acid, 3-aminobenzeneboronic acid, 4-aminobenzeneboronic acid, 3-acrylamidophenylboronic acid, 3-fluoro-4-aldophenylboronic acid, 4-fluoro-2-aldophenylboronic acid, 4-fluoro-3-aldophenylboronic acid, 4-carbamoylphenylboronic acid, 3-amino-4-fluorobenzeneboronic acid, 3-amino-5-fluorobenzeneboronic acid, 3- (2-carbonylvinyl) phenylboronic acid and 4-formylphenylboronic acid;

preferably, the cross-linking agent is at least one of formaldehyde, glyoxal and glutaraldehyde.

4. The method of making a boronic acid modified metal oxide nanoarray-MOF composite of claim 1,

the mass ratio of the surface stabilizer to the metal oxide nano array-MOF composite material is 1-3: 1;

preferably, the concentration of the boric acid functional monomer is 3% -15%.

5. The method of making a boronic acid modified metal oxide nanoarray-MOF composite of claim 1,

the carbonization treatment in the step a) is carried out in the atmosphere of air in a muffle furnace, the temperature is 200-500 ℃, the heating rate is 3-10 ℃/min, and the reaction time is 1.5-5 h.

6. The method of making a boronic acid modified metal oxide nanoarray-MOF composite according to claim 1, wherein the in-situ grown MOF material in step b) is an in-situ grown MOF material by room temperature rest, hydrothermal reaction, or solvothermal method;

preferably, the reaction time of the room-temperature rest is 30min-36 h; the temperature of the hydrothermal reaction is 80-200 ℃, and the reaction time is 5-30 h.

7. The method of making a boronic acid modified metal oxide nanoarray-MOF composite of claim 1,

the shape of the nano array in the step a) is at least one of a nano wire, a nano rod, a nano sheet, a nano belt and a nano flower.

8. The boronic acid-modified metal oxide nanoarray-MOF composite material prepared by the method of any one of claims 1 to 7, wherein the boronic acid-modified metal oxide nanoarray-MOF composite material is used in a biosensor.

9. A biosensor is characterized in that the biosensor is a three-electrode system which is formed by taking the boric acid modified metal oxide nano array-MOF composite material as a flexible self-supporting working electrode according to claim 8, taking an Ag/AgCl or saturated calomel electrode as a reference electrode and taking a platinum wire or a platinum sheet as a counter electrode, an electrochemical signal of the working electrode is detected through an electrochemical workstation, and cis-dihydroxy biomolecules are detected through the strength of the electrochemical signal.

10. The biosensor of claim 9, wherein the cis-dihydroxy biomolecule is a biomolecule of the 1,2/1, 3-cis diol structure; preferably one of a nucleotide, a glycoside, a polysaccharide, dopamine, epinephrine and glycoprotein.

Technical Field

The invention belongs to the technical field of nano composite materials, and particularly relates to a boric acid modified metal oxide nano array-MOF composite material, and a preparation method and application thereof.

Background

The transition metal oxide nano materials have good semiconductivity, electrocatalysis and redox capability, and the cost is low, so the transition metal oxide nano materials are widely concerned in the field of biosensing. But the performance of the constructed biosensors is not generally high. The main reasons are that: 1) the non-noble metal oxide belongs to semiconductor materials, has the characteristics of semiconductors, is poor in conductivity, and slow in electron transfer rate, so that the sensitivity of the sensor is low; 2) the non-noble metal oxide nano material is simply stacked, the effective reaction area is small, and the performance of the constructed biosensor is not high; 3) most of the synthesized non-noble metal enzyme-free sensing nano materials need to be fixed on electrodes such as glassy carbon and the like by using a conductive adhesive, and the use of the adhesive can bury partial active sites and reduce the catalytic activity. In recent years, researchers compound metal oxides and carbon materials, so that the problem of poor conductivity of the metal oxides can be solved, and the catalytic activity of the electrode material can be further improved by utilizing the synergistic catalytic action of the carbon materials and the metal oxide nano materials on target analytes, so that the performance of the sensor is improved. Meanwhile, in order to further improve the response signal of the biosensing, the sensing material is modified by biomolecules, so that the specific recognition capability of the sensing material is improved, and the selectivity and the sensitivity of the electrochemical biosensor are improved.

Metal-Organic Frameworks (MOFs) are porous materials with various structures and easy modification, are widely concerned due to the ultrahigh porosity and huge specific surface area, and have potential application prospects in the fields of catalysis, separation, sensors, gas adsorption and storage and the like. Although MOFs have outstanding catalytic activity, there are problems of poor conductivity and easy structural collapse,

disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a preparation method of a boric acid modified metal oxide nano array-MOF composite biosensor, the composite material prepared by the method has good electrical conductivity of a carbon material and excellent electrocatalytic properties of the metal oxide nano array and the MOF material, and can be used for electrochemically detecting cis-dihydroxy biomolecules by modification of phenylboronic acid functional groups.

In order to achieve the purpose, the invention adopts the following technical scheme:

a preparation method of a boric acid modified metal oxide nano array-MOF composite material comprises the following steps:

(a) preparation of metal oxide nano-arrays: firstly, growing any one or two of copper, cobalt, nickel, iron, zinc and manganese on the surface of carbon cloth by combining a hydrothermal method, a solvothermal method and an electrochemical deposition method with carbonization treatment to form a single metal or double metal oxide nano array;

(b) preparing a MOF material modified metal oxide nano array: taking the metal oxide nano array obtained in the step (a) as a substrate, adding 5-20 parts by weight of surfactant, 20-200 parts by weight of organic ligand, 100-800 parts by weight of organic solvent and 5-20 parts by weight of metal salt, and growing an MOF material in situ to obtain a metal oxide nano array-MOF composite material;

(c) preparation of the boric acid modified metal oxide nano array-MOF composite material: modifying the material obtained in the step (b) by using a surface stabilizer, then immersing the modified material into a solution containing a boric acid group functional monomer for 3-10 hours, adding the composite material into a cross-linking agent solution or cross-linking agent saturated steam, and reacting for 3-20 hours to obtain the boric acid modified metal oxide nano array-MOF composite material.

On the basis of the scheme, in the step b):

the surfactant is at least one of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, polyvinyl alcohol, triethylamine, triethyldiamine, polyethylene pyrrolidone, polyacrylamide, polypropylene imine, alkyl sodium sulfonate, sodium fatty acid, polyoxyethylene ether, sodium carboxylate, hexadecyl trimethyl ammonium bromide, polyethylene glycol, polyethylene oxide, P123 and F127;

preferably, the organic ligand is selected from at least one of 2-aminoterephthalic acid, 2-hydroxyterephthalic acid, 2, 5-diaminoterephthalic acid, 2, 5-dihydroxyterephthalic acid, terephthalic acid, trimesic acid, 2-methylimidazole, benzimidazole, 2-nitroimidazole and 4-nitroimidazole;

preferably, the organic solvent is at least one of methanol, ethanol, water and DMF;

preferably, the metal salt is at least one of copper, cobalt, nickel, iron, zinc and manganese salts, and preferably, the metal salt is one of nitrate, acetate, sulfate and chlorate.

On the basis of the scheme, in the step c):

the surface stabilizer is at least one of imidazole-2-formaldehyde, 2-aminoimidazole, 4-imidazole formaldehyde, 1-ethyl-1H-imidazole-2-formaldehyde and 1-methyl-1H-imidazole-2-formaldehyde;

the surface stabilizer in the step (c) of the invention has two functions, namely, the surface modification of the metal oxide nano array-MOF composite material is provided with amino/aldehyde groups, and meanwhile, imidazole rings have the function of stabilizing the MOF material.

Preferably, the borate functional monomer is at least one of 2-aminobenzeneboronic acid, 3-aminobenzeneboronic acid, 4-aminobenzeneboronic acid, 3-acrylamidophenylboronic acid, 3-fluoro-4-aldophenylboronic acid, 4-fluoro-2-aldophenylboronic acid, 4-fluoro-3-aldophenylboronic acid, 4-carbamoylphenylboronic acid, 3-amino-4-fluorobenzeneboronic acid, 3-amino-5-fluorobenzeneboronic acid, 3- (2-carbonylvinyl) phenylboronic acid and 4-formylphenylboronic acid;

preferably, the cross-linking agent is at least one of formaldehyde, glyoxal and glutaraldehyde.

On the basis of the scheme, the mass ratio of the surface stabilizer to the metal oxide nano array-MOF composite material is 1-3: 1;

preferably, the concentration of the boric acid functional monomer is 3% -15%.

On the basis of the scheme, the carbonization treatment in the step a) is carried out in the atmosphere of air in a muffle furnace, the temperature is 200-500 ℃, the heating rate is 3-10 ℃/min, and the reaction time is 1.5-5 h.

On the basis of the scheme, the MOF material in-situ growth in the step b) is obtained by carrying out room-temperature standing, hydrothermal reaction or solvothermal method on the MOF material in-situ growth;

preferably, the reaction time of the room-temperature rest is 30min-36 h; the temperature of the hydrothermal reaction is 80-200 ℃, and the reaction time is 5-30 h.

On the basis of the scheme, the shape of the nano array in the step a) is at least one of a nano wire, a nano rod, a nano sheet, a nano belt and a nano flower.

The boric acid modified metal oxide nano array-MOF composite material prepared by the method is used for biosensors.

A biosensor is a three-electrode system which is formed by taking the boric acid modified metal oxide nano array-MOF composite material as a flexible self-supporting working electrode, an Ag/AgCl or saturated calomel electrode as a reference electrode and a platinum wire or a platinum sheet as a counter electrode, an electrochemical signal of the working electrode is detected through an electrochemical workstation, and cis-dihydroxy biomolecules are detected through the electrochemical signal intensity.

On the basis of the scheme, the cis-dihydroxy biomolecule is a biomolecule with a 1,2/1, 3-cis-diol structure; preferably one of a nucleotide, a glycoside, a polysaccharide, dopamine, epinephrine and glycoprotein.

The technical scheme of the invention has the advantages that:

(1) the carbon cloth three-dimensional self-supporting nano array is designed to be used as an electrode to construct an electrochemical biosensor, so that the use of an adhesive in the fixing process of an electrocatalyst is avoided, more active sites are exposed, and the three-dimensional framework material of the self-supporting material has the characteristics of light weight, large specific surface area, high mechanical strength, stable performance, processability, good conductivity and the like;

2) different synthesis methods and synthesis conditions are controlled, transition metal oxide nano arrays with different particle sizes or morphologies are obtained on the self-supporting carbon cloth, and a nano-structure material MOF material is further grown, so that a larger specific surface area of the electrocatalyst is obtained, the effective reaction area of the sensor is greatly enlarged, and more active sites are favorably exposed;

(3) the metal oxide, the MOF material and the carbon material are compounded, so that the problem of poor conductivity of the metal oxide and the MOF material can be solved, and the catalytic activity of the electrode material can be further improved by utilizing the synergistic catalytic action of the metal oxide, the MOF material and the carbon material on biomolecules, so that the performance of the sensor is improved;

(4) according to the metal oxide nano array-MOF composite material obtained by the invention, MOF particles are uniformly distributed on the surface and inside of the metal oxide nano array and have good binding force with the metal oxide nano array, so that the falling of the MOF particles in the reaction process is effectively reduced, and the cyclic use stability of the composite material in the electrochemical biosensing process is ensured.

Drawings

FIG. 1 is a boronic acid modified FeCo₂O₄SEM photograph of nanosheet array-MOF composite

FIG. 2 is a cyclic voltammogram of different modified electrodes in phosphate buffered saline at 50. mu.M dopamine, 0.1M, pH 7.0

FIG. 3 is a boronic acid modified FeCo₂O₄A cyclic voltammogram of a phosphoric acid buffer solution containing 50 mu M of dopamine is obtained by using a nanosheet array-MOF composite material modified electrode at different scanning rates, wherein the pH value of the electrode is 7.0;

FIG. 4 is a graph of oxidation peak current versus scan rate in a linear fashion;

FIG. 5 is the oxidation peak current measured in 8 replicates after elution of the modified electrode;

FIG. 6 shows boric acid modified MnCo₂O₄SEM photographs of the nanoflower array-MOF composite;

FIG. 7 boronic acid modified MnCo₂O₄Detecting differential pulse voltammograms of adrenalin with different concentrations by using a nanoflower array-MOF composite material electrode;

fig. 8 is a linear relationship between epinephrine and oxidation peak current at different concentrations.

Detailed Description

Terms used in the present invention have generally meanings as commonly understood by one of ordinary skill in the art, unless otherwise specified.

The present invention will be described in further detail with reference to the following data in conjunction with specific examples. The following examples are intended to illustrate the invention and are not intended to limit the scope of the invention in any way.