Preparation method and application of bimanual β -CD @ Cu-MOF nano composite sensor
阅读说明：本技术 一种双手性β-CD@Cu-MOF纳米复合传感器的制备方法和应用 (Preparation method and application of bimanual β -CD @ Cu-MOF nano composite sensor ) 是由 侯莹 匡轩 于 2020-03-12 设计创作，主要内容包括：本发明公开了一种双手性β-CD@Cu-MOF纳米复合传感器的制备方法及基于该传感器作为同时电化学传感酪氨酸和青霉胺异构体的应用,属于纳米复合材料技术、电催化技术和异构体识别技术领域。其主要步骤是将硝酸铜溶液和配体溶液混合,室温静置制备Cu-MOF纳米纤维；Cu-MOF纳米纤维和β-环糊精β-CD共混,滴涂在玻碳电极GCE上,制得双手性β-CD@Cu-MOF/GCE纳米复合传感器。该传感器制备所用原料成本低,反应能耗低,制备方法简单高效。将该传感器作为同时电化学传感酪氨酸和青霉胺异构体的应用,具有灵敏度高、设备简单和电化学稳定性高等优势,具有良好的工业前景。(The invention discloses a preparation method of a bimanual β -CD @ Cu-MOF nano composite sensor and application of the sensor as simultaneous electrochemical sensing of tyrosine and penicillamine isomers, and belongs to the technical field of nano composite material technology, electrocatalysis technology and isomer identification.)
1. A preparation method of a bimanual β -CD @ Cu-MOF nano composite sensor is characterized by comprising the following steps:
0.58-0.62 g of Cu (NO)3)2·3H2Mixing O with 3-7 m L of water to obtain a copper nitrate solution;
adding 0.05-0.06 g of ligand L-aspartic acid L-Asp and 0.03-0.04 g of NaOH into 3-7 m L water, and carrying out 180W ultrasonic treatment for 2-4 min to obtain a clear ligand solution;
uniformly mixing a copper nitrate solution and a ligand solution, standing for 4-6 h at room temperature, performing centrifugal separation, washing the obtained solid with water and ethanol for three times respectively, and drying at 85 ℃ to constant weight to obtain Cu-MOF nanofibers;
6 mg of Cu-MOF nanofiber, 6 mg of β -cyclodextrin β -CD, 720 mu L of water, 250 mu L of ethanol and 30 mu L of Nafion are mixed, ultrasonic treatment is carried out for 30 min at 180W, β -CD @ Cu-MOF nanofiber suspension is prepared, 10 mu L of solution is dropwise coated on a glassy carbon electrode GCE, and the glassy carbon electrode GCE is dried overnight at room temperature, so that a β -CD @ Cu-MOF/GCE electrode, namely a double-handed β -CD @ Cu-MOF/GCE nano composite sensor is obtained.
2. The method for preparing bimanual β -CD @ Cu-MOF nano composite sensor according to claim 1, wherein the Cu-MOF nano fiber has a longitudinal longest fiber length of up to 1mm and a diameter width of 40-100nm, and the Cu-MOF nano fiber has a basic unit structure of Cu L (H L)2O) of one CuIIPositive ion, one LIINegative ions and an H2O molecule, said LIIThe ion is aspartic acid H2L LIIAnd (4) negative ions.
3. The method for preparing the bimanual β -CD @ Cu-MOF nanocomposite sensor of claim 1, wherein the bimanual β -CD @ Cu-MOF/GCE nanocomposite sensor has β -CD and L bimanual sitesIINegative ions, β -CD, were loaded in the voids and surface of the Cu-MOF.
4. Use of bimanual β -CD @ Cu-MOF nanocomposite sensor prepared according to the preparation method of claim 1 as a simultaneous electrochemical sensing of tyrosine and penicillamine isomers.
Technical Field
The invention discloses a preparation method of a bimanual β -CD @ Cu-MOF nano composite sensor and application of the sensor as simultaneous electrochemical sensing of tyrosine and penicillamine isomers, and belongs to the technical fields of nano composite material technology, electrocatalysis technology and isomer identification technology.
Background
Cyclodextrins (CDs) are a class of cyclic oligosaccharides consisting of 6, 7 or 8 glucose units (designated α -, β -or-CD, respectively) in a ring shape with a hydrophobic internal cavity and a hydrophilic external structure. CD is less costly and has an excellent ability to efficiently and selectively hold various compounds in their hydrophobic cavities to form host-guest inclusions. these properties make them of great significance indeed, CD has been widely used in the field of electroanalytical chemistry and in the construction of chiral sensors, several CDs-based electrochemical methods have been developed to identify electroactive chiral molecules [ Upradhyay, S.S.; Kalamate, P.K.; Srivastava, A.K. Electrochim. Acta 2017, 248, 258-however, almost all technical schemes developed, including CDs-based sensor chiral identification, cannot directly achieve selective and quantitative determinations and generally involve only one signal transduction mechanism, which has been recently investigated in combination with several isomers to enable quantitative determination of CD by our research.
It is not ideal to construct an electrochemical sensor directly using only pure CD. The requirement for an effective electrochemical chiral sensor is not only to distinguish each enantiomer, but also to distinguish and improve the response signal.
Metal-organic frameworks (MOFs) refer to crystalline porous materials with periodic network structures formed by self-assembly of transition metal ions and organic ligands, and the three-dimensional pore structure of the crystalline porous materials comprises two important components: junctions (connectors) and bridges (linkers), typically with metal ions as the junction, are supported by organic ligands forming spatial 3D extensions, yet another porous material than zeolites and carbon nanotubes. MOFs materials have the advantage that they are inherently thick: the size, specific surface area, active sites and rigidity and flexibility of the pore channels can be regulated and controlled by reasonably selecting metal ions and organic ligands. Therefore, the composite material formed by the CD and the MOF has application value.
Electrochemical chiral recognition has received much attention because of its many advantages, such as low cost, fast response, inexpensive instrumentation and miniaturization. However, most of the current electrochemical sensors generally only relate to a signal mechanism, and have low sensitivity and low sensor utilization rate. Therefore, the construction of a high-sensitivity sensor for simultaneously detecting two amino acid isomers has important significance.
Disclosure of Invention
One of the technical tasks of the invention is to make up the defects of the prior art, and provide a preparation method of the bimanual β -CD @ Cu-MOF nano composite sensor, wherein the sensor is low in raw material cost, low in reaction energy consumption, simple and efficient in preparation method.
The second technical task of the invention is to provide the application of the sensor, namely the application of the β -CD @ Cu-MOF nano composite sensor as the simultaneous electrochemical sensing of tyrosine and penicillamine isomers, and the sensor has the advantages of high sensitivity, simple equipment, high electrochemical stability and the like, and has good industrial prospect.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
1. preparation method of bimanual β -CD @ Cu-MOF nano composite sensor
0.58-0.62 g of Cu (NO)3)2·3H2Mixing O with 3-7 m L of water to obtain a copper nitrate solution;
adding 0.05-0.06 g of ligand L-aspartic acid L-Asp and 0.03-0.04 g of NaOH into 3-7 m L water, and carrying out 180W ultrasonic treatment for 2-4 min to obtain a clear ligand solution;
uniformly mixing a copper nitrate solution and a ligand solution, standing for 4-6 h at room temperature, performing centrifugal separation, washing the obtained solid with water and ethanol for three times respectively, and drying at 85 ℃ to constant weight to obtain Cu-MOF nanofibers;
6 mg of Cu-MOF nanofiber, 6 mg of β -cyclodextrin β -CD, 720 mu L of water, 250 mu L of ethanol and 30 mu L of Nafion are mixed, ultrasonic treatment is carried out for 30 min at 180W, β -CD @ Cu-MOF nanofiber suspension is prepared, 10 mu L of solution is dropwise coated on a glassy carbon electrode GCE, and the glassy carbon electrode GCE is dried overnight at room temperature, so that a β -CD @ Cu-MOF/GCE electrode, namely a double-handed β -CD @ Cu-MOF/GCE nano composite sensor is obtained.
The longest longitudinal fiber length of the Cu-MOF nanofiber can reach 1mm, the diameter width of the Cu-MOF nanofiber is 40-100nm, and the basic unit structure Cu L (H) of the Cu-MOF nanofiber2O) of one CuIIPositive ion, one LIINegative ions and an H2O molecule composition; what is needed isLIIThe ion is aspartic acid H2L LIIAnd (4) negative ions.
The double-chiral β -CD @ Cu-MOF/GCE nano composite sensor has double chiral sites of β -CD and LIINegative ions, β -CD, were loaded in the voids and surface of the Cu-MOF.
2. The bimanual β -CD @ Cu-MOF nanocomposite sensor prepared by the preparation method is applied to simultaneously and electrochemically sensing tyrosine and penicillamine isomers, and the steps are as follows:
(1) preparing standard solution
Respectively preparing standard solutions of D-tyrosine, L-tyrosine, D-penicillamine and L-penicillamine with series concentrations by using KOH aqueous solution with the concentration of 0.1M;
(2) detection of D-tyrosine, L-tyrosine, D-penicillamine and L-penicillamine isomers
Respectively measuring the current values of the D-tyrosine, L-tyrosine, D-penicillamine and L-penicillamine standard solutions with various concentrations in the step (1) by adopting a linear scanning cyclic voltammetry method and drawing working curves of the D-tyrosine, L-tyrosine, D-penicillamine and L-penicillamine isomers based on the β -CD @ Cu-MOF nano composite sensor by adopting the prepared bimanular β -CD @ Cu-MOF nano composite sensor as a working electrode, a platinum sheet as an auxiliary electrode and a calomel electrode as a reference electrode;
replacing the standard solution with a sample solution to be tested containing a mixture of D-tyrosine, L-tyrosine, D-penicillamine and L-penicillamine, and measuring the recognition effect and the content of the isomers of the D-tyrosine, L-tyrosine, D-penicillamine and L-penicillamine.
The electrochemical data of the sensor simultaneously shows oxidation peaks of D-tyrosine, L-tyrosine, D-penicillamine and L-penicillamine, the electrochemical chiral recognition of tyrosine and penicillamine isomers is realized, and the detection range of a D-tyrosine and L-tyrosine isomer solution is 0.1-1.0 × 10-8g/L, and the detection range of the D-penicillamine and L-penicillamine isomer solution is 0.1-3.2 × 10-10g/L。
The beneficial technical effects of the invention are as follows:
(1) the β -CD @ Cu-MOF nano composite sensor is prepared by mixing a copper nitrate solution and a ligand solution, standing at room temperature to prepare Cu-MOF nanofibers, blending the Cu-MOF nanofibers with β -cyclodextrin β -CD, and dripping the blend on a glassy carbon electrode GCE to prepare the bimanual β -CD @ Cu-MOF/GCE nano composite sensor.
(2) The double-chiral β -CD @ Cu-MOF/GCE nano composite sensor contains a β -CD hydrophobic inner cavity and a hydrophilic external structure, and also contains a Cu-MOF nanocrystalline chiral site, and as an application of electrochemical sensing of tyrosine and penicillamine isomers, oxidation peaks of D-tyrosine, L-tyrosine, D-penicillamine and L-penicillamine appear in electrochemical data at the same time, so that electrochemical chiral recognition of the tyrosine and penicillamine isomers is realized, and the sensor has the advantages of high sensitivity, simple equipment, high electrochemical stability and the like, and has a good industrial prospect.
Detailed Description
The present invention is further described with reference to the following examples, but the scope of the present invention is not limited to the examples, and modifications made by those skilled in the art to the technical solutions of the present invention should fall within the scope of the present invention.