In-situ magnetic field regulation and control device suitable for single-molecule fluorescence super-resolution microscope

Abstract

The invention relates to an in-situ magnetic field regulation and control device suitable for a single-molecule fluorescence super-resolution microscope, and belongs to the technical field of photochemistry. Aiming at the urgent need of researching the regulation effect of the magnetic field on the photocatalytic reaction, the invention makes up for the lack of a magnetic field regulation device suitable for the single-molecule super-resolution fluorescence microscope, and has good practical application value. The SMFM is utilized, and the space-time regulation and control of the magnetic field on the photocatalytic oxygen evolution activity of the surfaces of the ZnO nanorod particles under the in-situ condition are disclosed. According to the invention, the key effects of the magnetic field vector effect, including improvement of the separation efficiency of photon-generated carriers and influence on the spatial distribution of the photon-generated carriers, are identified. And in combination with DFT theoretical calculation, the enhancement of the magnetic field generated by the atomic electron cloud magnetic induction polarization effect is revealed, so that the action mechanism of the atomic level of the magnetic field effect is further revealed. The magnetic induction polarization effect is further enhanced by doping Fe atoms, so that the photocatalytic oxygen evolution efficiency of the ZnO nanorod array is optimized. The constructed imaging tool and analysis framework paves a new way for the mechanism and efficient utilization of the external field effect, and has wide guiding significance for the design of a semiconductor catalyst.

Description

Technical Field

[0001] The present invention belongs to the technical field of photochemistry, and in particular relates to a magnetic field in-situ control device suitable for a single-molecule super-resolution fluorescence microscope and its application in a photocatalytic process. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] With the high-quality development of the economy and society, human demand for clean energy technology continues to increase. Converting solar energy into chemical energy through photocatalytic technology is the clean energy technology with the most promising application prospects. However, photocatalytic technology currently faces the problem of low energy conversion efficiency, and the construction of efficient photocatalysts and photocatalytic systems is still a scientific problem that needs to be solved urgently. Studies have shown that magnetic field regulation can significantly improve the photocatalytic reaction rate and energy conversion efficiency, but the mechanism of magnetic field regulation of photocatalytic redox reactions is still unclear, and there is a lack of effective analytical characterization methods. In recent years, advanced imaging technologies such as single-molecule super-resolution positioning have been developed to analyze the mechanism of photocatalytic reactions, but the coupling of single-molecule microscopy and in-situ magnetic field regulation has become a bottleneck in the study of the mechanism of magnetically controlled photocatalytic reactions, making it difficult to visualize photocatalytic redox reactions on the surface of catalyst particles under different magnetic fields, and it is even more impossible to analyze the microscopic mechanism of magnetic field regulation or guide the synthesis of catalysts with good magnetic field response. Summary of the invention

[0004] In view of the deficiencies of the above-mentioned prior art, the present invention provides a magnetic field control device suitable for a single-molecule super-resolution fluorescence microscope to realize an in-situ control and analysis system and method for the photocatalytic oxidation reaction on the surface of catalyst particles during the actual photocatalytic process. The constructed magnetic field control device is mainly composed of two parallel coils connected in series. The electromagnetic effect is generated by the coils, which is conducive to the rapid adjustment of the magnetic field size. Secondly, the magnetic flux lines between the parallel coils in series are parallel and evenly distributed, which is conducive to the regulation of the direction of the magnetic field. Due to the existence of the parallel and evenly distributed magnetic field between the parallel coils in series, the photogenerated carriers moving inside the catalyst particles move in opposite directions under the action of the Lorentz force. Photogenerated electrons (e - ) and photogenerated holes (h +) separation, the efficiency of the photocatalytic reaction is improved. Therefore, the magnetic field control device can meet the catalytic reaction control; on the other hand, the structure of the magnetic field control device is suitable for a single-molecule super-resolution fluorescence microscopy system. A sufficient distance is reserved between the parallel coils so that the imaging focal plane of the microscope is located in the middle of the parallel coils, thereby realizing the in-situ monitoring of the control process of the photocatalytic oxidation reaction under the magnetic field at the single-molecule level, which helps to realize the visualization of the photocatalytic oxidation reaction on the surface of the catalyst particles under the magnetic field, and is used for the single-molecule dynamics analysis of the redox reaction under the action of the magnetic field and the analysis of the microscopic mechanism of electric field control, and has good practical application value.

[0005] In order to achieve the above technical objectives, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, the present invention provides an in-situ magnetic field control device suitable for single-molecule fluorescence super-resolution microscopy, comprising: a plurality of coils; the plurality of coils are connected in parallel in series and are spaced apart from each other;

[0007] When the coil is energized, a parallel and evenly distributed magnetic field is generated.

[0008] After the coils are connected in parallel, space is reserved between the coils so that they can be placed on both sides of the imaging focal plane of the microscope to meet the requirements of single-molecule super-resolution fluorescence imaging. Therefore, in some embodiments, the distance between the coils is 39-42 mm.

[0009] In some embodiments, the coil dimensions are as follows: a width of 17.5-18 mm, an inner diameter of 30-32 mm, and an outer diameter of 62-64 mm.

[0010] In some embodiments, the coil is made of copper wire with a magnetic permeability of 0.9999912 and an electrical conductivity of 59.5 x 10 6 S / M, dielectric constant is 1, number of turns is 360 turns.

[0011] In some embodiments, a constant current is passed through the coil, and the current ranges from 0.0A to 5.0A.

[0012] In some embodiments, the magnetic field generated by the coil ranges from 0.0 mT to 28.0 mT.

[0013] The second aspect of the present invention provides the application of the above-mentioned in-situ magnetic field control device suitable for single-molecule fluorescence super-resolution microscopy for quantitative detection at the single-molecule level in real-time in-situ photocatalysis.

[0014] The third aspect of the present invention provides a method for constructing a magnetic field control device suitable for a single-molecule super-resolution fluorescence microscope, comprising:

[0015] Connecting the coils in parallel in series can generate a parallel and uniformly distributed magnetic field between the coils to meet the requirements of magnetic field control;

[0016] After the coils are connected in parallel, space is reserved between the coils so that they can be placed on both sides of the imaging focal plane of the microscope to meet the needs of single-molecule super-resolution fluorescence imaging.

[0017] Connect the parallel series coils to a voltage and current stabilizing power supply and pass a constant current, so that a controllable inductive magnetic field is generated between the coils.

[0018] A fourth aspect of the present invention provides the use of the above-mentioned in-situ magnetic field control device suitable for single-molecule fluorescence super-resolution microscopy in controlling the photocatalytic oxidation reaction occurring on the surface of ZnO nanorod photocatalyst particles.

[0019] More specifically, by performing detection and analysis under different magnetic fields through single-molecule level imaging, the super-resolution spatial distribution of the photocatalytic oxidation reaction occurring on the surface of the ZnO photocatalyst particles is obtained.

[0020] The magnetic field control device is used to analyze the activity of the photocatalytic oxidation reaction occurring on the surface of the ZnO nanorod photocatalyst particles, and the frequency of the photocatalytic oxidation reaction occurring on the surface of the ZnO nanorod photocatalyst particles under different magnetic fields is quantified;

[0021] The regulation pathway of photocatalytic oxidation reaction on the surface of ZnO photocatalyst particles by analyzing the magnetic field through the spatial distribution of photocatalytic oxidation reaction;

[0022] In some embodiments, the reaction solution includes an oxidation reaction solution in which a photogenerated electron scavenger MV 2+ .

[0023] The beneficial effects of the present invention are:

[0024] (1) Compared with the prior art, the present invention fills the gap in the magnetic field control device for single-molecule super-resolution fluorescence microscopy, making it possible to analyze the control process of the magnetic field during the photocatalytic reaction.

[0025] (2) The operation method of the present application is simple, universal, and easy to scale up for production. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings in the specification, which constitute a part of the present application, are used to provide further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0027] Figure 1 It is a top view schematic diagram of a magnetic field control device suitable for single-molecule super-resolution fluorescence microscopy of the present invention;

[0028] Figure 2 It is a visual measurement schematic diagram of a magnetic field control device suitable for a single-molecule super-resolution fluorescence microscope of the present invention;

[0029] Figure 3 This is a physical device diagram of a magnetic field control device suitable for a single-molecule super-resolution fluorescence microscope of the present invention;

[0030] Figure 4 This is an experimental diagram of the electromagnetic response of the magnetic field control device of the present invention;

[0031] Figure 5 It is the photocatalytic oxygen evolution activity of ZnO nanorods under different magnetic field strengths and directions. DETAILED DESCRIPTION

[0032] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used in the present application have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0033] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0034] As introduced in the background technology, due to the lack of magnetic field control devices suitable for single-molecule super-resolution fluorescence microscopy, it is difficult for us to realize the visualization of photocatalytic oxidation reactions on the surface of catalyst particles under different magnetic fields, and it is even more difficult to analyze the microscopic mechanism of magnetic field control and guide the synthesis of catalysts with excellent magnetic field response.

[0035] In view of this, in a specific embodiment of the present invention, a magnetic field control device suitable for single-molecule super-resolution fluorescence microscopy is constructed. The method includes: connecting parallel coils in series; reserving spaces between parallel coils; inputting coil currents; and the magnetic field control device controls the photocatalytic oxidation reaction occurring on the surface of ZnO nanorod photocatalyst particles.

[0036] In a first aspect of the present invention, a magnetic field control device suitable for single-molecule super-resolution fluorescence microscopy is constructed, and the method comprises:

[0037] --Series connection of parallel coils: In order to make the direction and magnitude of the current between the coils consistent, the two parallel coils are first connected in series.

[0038] The specific method of connecting parallel coils in series is as follows: after the coil is wound with copper wire, it is extended to the next coil for winding. This ensures the stable series connection of the two coils. After the copper wire is wound, it is wrapped with insulating tape to ensure the safety of electricity use.

[0039] --Reservation of space between parallel coils: In order to make the device suitable for single-molecule super-resolution fluorescence microscopy, a certain amount of space is reserved between the parallel coils.

[0040] With reference to the diameter of the objective lens and the size of the stage, the reserved spacing between the parallel coils is 39 mm.

[0041] --Input of coil current: In order to form a parallel magnetic field between series-connected parallel coils, a stable current is input into the coil to form an inductive magnetic field.

[0042] The input current between the series parallel coils ranges from 0.0 A to 5.0 A. The magnetic field generated by the series parallel coils ranges from 0.0 mT to 28.0 mT.

[0043] In the second aspect of the present invention, the above-mentioned magnetic field control device is used to control the photocatalytic oxidation reaction occurring on the surface of ZnO nanorod photocatalyst particles. By performing detection and analysis under different magnetic fields by single-molecule level imaging, the super-resolution spatial distribution change and reaction frequency quantitative information of the photocatalytic oxidation reaction occurring on the surface of ZnO nanorod photocatalyst particles are obtained, and the control mechanism of the magnetic field control of the ZnO nanorod photocatalytic oxidation reaction is analyzed.

[0044] Among them, the magnetic field size range of the magnetic field control device is 0.0mT to 20.0mT. The photocatalytic oxidation reaction occurring on the surface of the ZnO nanorod photocatalyst particles is an oxidation reaction of Hydroxyphenyl Fluorescein (HPF). The products of the photocatalytic oxidation-reduction reaction are all HPFox. The product can be excited by a 488nm laser to produce a fluorescence signal with a maximum emission wavelength of 520nm. The present invention can use the fluorescence single molecule frequency and spatial distribution of the product to analyze the microscopic mechanism of magnetic field regulation of photocatalytic oxidation reaction. The single molecule fluorescence signal generated by the photocatalytic oxidation reaction occurring on the surface of the ZnO nanorod photocatalyst particles is observed and analyzed by a self-built single molecule super-resolution fluorescence microscopy system.

[0045] The present invention is further explained by the following examples, but it does not constitute a limitation of the present invention. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. In addition, the energy photocatalysis and photochemical technology methods not described in detail in the examples are all conventional methods in the art, and the specific operations can refer to the energy photocatalysis and photochemical technology guide or product instructions.

[0046] Embodiment 1:

[0047] The synthesis of ZnO nanorod arrays by the present invention realizes full utilization of the magnetic field vector effect. Using SMFM, the temporal and spatial regulation of the magnetic field on the photocatalytic oxygen evolution activity on the surface of ZnO nanorod particles under in-situ conditions is revealed. The present invention identifies the key role of the magnetic field vector effect, including improving the separation efficiency of photogenerated carriers and affecting the spatial distribution of photogenerated carriers. Combined with DFT theoretical calculations, the magnetic field enhancement generated by the magnetic polarization effect of the atomic electron cloud is revealed, thereby further revealing the atomic level mechanism of the magnetic field effect. The present invention further strengthens the magnetic polarization effect by doping Fe atoms, thereby optimizing the photocatalytic oxygen evolution efficiency of the ZnO nanorod array. The constructed imaging tools and analysis framework pave a new way for the mechanism and efficient utilization of the external field effect, and have broad guiding significance for the design of semiconductor catalysts.

[0048] Experimental steps for construction:

[0049] --Construction of a magnetic field control device: In order to achieve single-molecule level monitoring of the photocatalytic oxidation reaction on the surface of ZnO nanorods, the present invention first constructs a magnetic field control device. It consists of two parallel coils connected in series. Secondly, the reaction pool for the photocatalytic reduction reaction consists of a bottom layer (cover glass, 0.17 mm thickness), a top layer (slide, 1.0 mm thickness) and a microchannel (double-sided tape, 2.0 cm × 5.0 mm × 150 μm). The liquid channel is composed of a double-sided tape sandwiched between the bottom layer and the top layer. The present invention deposits the ZnO nanorod sample on the bottom layer of the microchannel in a monodisperse state and fixes it overnight at 90°C.

[0050] ----Single-molecule fluorescence imaging of photocatalytic oxidation reaction on the surface of ZnO nanorod particles:

[0051] The 500 nM hydroxyl radical fluorescent probe (HPF, Thermo Fisher Scientific) and 5 mM photogenerated electron scavenger (MV 2+ ) was continuously pumped into the reaction cell liquid channel (flow rate was 67 μL min -1 ). Under ultraviolet light (LED, 365nm), photocatalytic oxidation occurs on the surface of ZnO nanorods to generate catalytic products (HPFox). 488nm laser excites HPFox to emit a fluorescence signal (maximum emission wavelength is 520nm). When current is passed through the series parallel coils, a uniform magnetic field will be generated between the coils. By regulating the magnitude of the current, a controllable magnetic field between the coils can be constructed. The fluorescence signal generated by HPFox is collected using a 100× oil objective lens (HCX PL APO 100×0.47oil) and imaged using sCMOS (imaging rate is 30ms frame-1 );

[0052] All collected experimental data and single fluorescence images were processed using MetaMorph analysis software (Molecular Devices). The original single-molecule fluorescence time trace was processed by a 10% low-pass filter, and the single-molecule signal was screened by setting a threshold.

[0053] The linear relationship between coil current and magnetic induction intensity in the central area was tested when different voltages were applied, such as Figure 4 shown.

[0054] The burst frequency of single-molecule fluorescence reaction of single zinc oxide nanorod catalyst photocatalysis was tested at different magnetic induction intensity directions and sizes, such as Figure 5 shown.

[0055] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to perform equivalent replacements on parts thereof. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention. Although the above describes the specific implementation modes of the present invention in conjunction with the accompanying drawings, it is not intended to limit the protection scope of the present invention. Those skilled in the art should understand that, based on the technical solution of the present invention, various modifications or deformations that can be made by those skilled in the art without creative labor are still within the protection scope of the present invention.

Claims

1. An in-situ magnetic field control device suitable for single-molecule fluorescence super-resolution microscopy, characterized in that: include: A plurality of coils; the plurality of coils are connected in parallel and in series and are spaced apart from each other; When the coil is energized, a parallel and evenly distributed magnetic field is generated.

2. The in-situ magnetic field control device suitable for single-molecule fluorescence super-resolution microscopy according to claim 1, characterized in that: The distance between the coils is 39-42 mm.

3. The in-situ magnetic field control device suitable for single-molecule fluorescence super-resolution microscopy according to claim 1, characterized in that: The coil dimensions are specifically as follows: width is 17.5-18 mm, inner diameter is 30-32 mm, and outer diameter is 62-64 mm.

4. The in-situ magnetic field control device suitable for single-molecule fluorescence super-resolution microscopy according to claim 1, characterized in that: The coil is made of copper wire with a magnetic permeability of 0.9999912 and an electrical conductivity of 59.5 x 10 6 S / M, dielectric constant is 1, number of turns is 360 turns.

5. The in-situ magnetic field control device suitable for single-molecule fluorescence super-resolution microscopy according to claim 1, characterized in that: A constant current is passed through the coil, and the current range is 0.0A to 5.0A.

6. The in-situ magnetic field control device suitable for single-molecule fluorescence super-resolution microscopy according to claim 1, characterized in that: The magnetic field generated by the coil ranges from 0.0 mT to 28.0 mT.

7. Application of the in-situ magnetic field control device suitable for single-molecule fluorescence super-resolution microscopy as described in any one of claims 1 to 6 in single-molecule level quantitative detection during real-time in-situ photocatalysis.

8. A method for constructing a magnetic field control device suitable for single-molecule super-resolution fluorescence microscopy, comprising: Connecting the coils in parallel in series can generate a parallel and uniformly distributed magnetic field between the coils to meet the requirements of magnetic field control; After the coils are connected in parallel, space is reserved between the coils so that they can be placed on both sides of the imaging focal plane of the microscope to meet the needs of single-molecule super-resolution fluorescence imaging. Connect the parallel series coils to a voltage and current stabilizing power supply and pass a constant current, so that a controllable inductive magnetic field is generated between the coils.

9. Use of the in-situ magnetic field control device suitable for single-molecule fluorescence super-resolution microscopy as described in any one of claims 1 to 6 in controlling the photocatalytic oxidation reaction occurring on the surface of ZnO nanorod photocatalyst particles.

10. The use according to claim 9, characterized in that By performing detection and analysis under different magnetic fields through single-molecule level imaging, the super-resolution spatial distribution of the photocatalytic oxidation reaction occurring on the surface of ZnO photocatalyst particles was obtained. Or, the magnetic field control device is used to analyze the activity of the photocatalytic oxidation reaction occurring on the surface of the ZnO nanorod photocatalyst particles, and the frequency of the photocatalytic oxidation reaction occurring on the surface of the ZnO nanorod photocatalyst particles under different magnetic fields is quantified; Or, a regulation pathway for regulating the photocatalytic oxidation reaction occurring on the surface of ZnO photocatalyst particles by analyzing the magnetic field through the spatial distribution of the photocatalytic oxidation reaction; Or, the reaction solution includes an oxidation reaction solution and a photogenerated electron scavenger MV in a HPF solution. 2+ .

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