Method and device for detecting magnetic particles, electronic device and storage medium

Abstract

The application provides a magnetic particle detection method and device, an electronic device and a storage medium. The magnetic particle detection method comprises: applying an excitation light field to the side close to the substrate of a quantum sensing film to excite a near-surface two-dimensional color center ensemble to generate a fluorescence signal; applying a plurality of microwave fields with different preset microwave frequencies to the quantum sensing film in turn; collecting fluorescence images under the microwave field of each preset microwave frequency to obtain a plurality of fluorescence images; determining a fluorescence intensity change curve of each point of the quantum sensing film according to the plurality of fluorescence images; determining the magnetic field strength of each point according to the fluorescence intensity change curve of each point; determining a magnetic field strength distribution map perceived by the quantum sensing film according to the magnetic field strength of each point, so as to determine the parameter information of the magnetic particles in the sample to be measured according to the magnetic field strength distribution map.

Description

Technical Field

[0001] This application relates to the technical field of magnetic particle detection, and more specifically, to a method and apparatus for detecting magnetic particles, an electronic device, and a storage medium. Background Technology

[0002] Currently, in the manufacturing process of batteries (such as lithium-ion batteries), contamination by magnetic particles (such as iron, cobalt, and nickel) is one of the key factors affecting battery safety and performance. The presence of magnetic particles can lead to internal short circuits, thermal runaway, and reduced battery life. Therefore, rigorous testing for magnetic particles in batteries is crucial.

[0003] Existing methods for detecting magnetic particles in batteries generally involve: first, enriching the magnetic particles in the battery material using a magnetic rod; then, cleaning the enriched material with a strong acid such as aqua regia; and finally, quantitatively determining the magnetic elements using inductively coupled plasma atomic emission spectrometry. However, the inventors of this application have discovered that the above-mentioned detection methods suffer from at least the problems of long detection cycles, inability to achieve online detection, and relatively delayed detection results, which affect the product qualification rate.

[0004] The content in the background section is merely technology known to the public and does not necessarily represent existing technology in this field. Summary of the Invention

[0005] This application provides a method and apparatus for detecting magnetic particles, an electronic device, and a storage medium, which aims to solve at least one of the technical problems mentioned in the background art.

[0006] According to one aspect of this application, a method for detecting magnetic particles is provided, comprising: applying an excitation light field to a side of a quantum sensing film near a substrate to excite a near-surface two-dimensional color center ensemble to generate a fluorescence signal; sequentially applying multiple microwave fields with different preset microwave frequencies to the quantum sensing film; acquiring fluorescence images under each preset microwave frequency microwave field to obtain multiple fluorescence images; determining the fluorescence intensity variation curve of each point on the quantum sensing film based on the multiple fluorescence images; determining the magnetic field strength at each point based on the fluorescence intensity variation curve of each point; determining the magnetic field strength distribution map sensed by the quantum sensing film based on the magnetic field strength at each point, so as to determine the parameter information of magnetic particles in the sample to be tested based on the magnetic field strength distribution map.

[0007] According to some embodiments of this application, determining the magnetic field strength at each point based on the fluorescence intensity change curve of each point includes: determining the resonance frequency of the point based on the fluorescence intensity change curve; and determining the magnetic field strength based on the resonance frequency.

[0008] According to some embodiments of this application, acquiring fluorescence images under a microwave field at each preset microwave frequency to obtain multiple fluorescence images includes: acquiring multiple fluorescence images through a multi-pixel wide-field imaging system or a scanning microscopy imaging system.

[0009] According to some embodiments of this application, the sample to be tested is a battery electrolyte; the magnetic particles include at least one of the following metal particles: lithium, iron, copper, nickel, cobalt, and aluminum.

[0010] According to some embodiments of this application, the quantum sensing thin film is made of at least one of diamond, hexagonal boron nitride, and silicon carbide; the near-surface two-dimensional color center ensemble includes at least one of nitrogen-vacancy color centers, silicon-vacancy color centers, boron-vacancy color centers, or other solid-state spin color centers formed by crystal defects.

[0011] According to some embodiments of this application, the near-surface two-dimensional color center ensemble is located within a predetermined depth range on the surface of the quantum sensing thin film; wherein, the predetermined depth range is 2nm-20nm.

[0012] According to another aspect of this application, a magnetic particle detection device is provided, comprising a quantum sensing thin film, an optical excitation module, a microwave excitation module, an imaging detection module, and a data processing module. The quantum sensing thin film includes a substrate and a near-surface two-dimensional color center ensemble disposed on the substrate, the near-surface two-dimensional color center ensemble serving to hold the sample to be tested. The optical excitation module applies an excitation light field to the side of the quantum sensing thin film near the substrate to excite the near-surface two-dimensional color center ensemble to generate a fluorescence signal. The microwave excitation module sequentially applies multiple microwave fields with different preset microwave frequencies to the quantum sensing thin film. The imaging detection module acquires fluorescence images under each preset microwave frequency microwave field to obtain multiple fluorescence images. The data processing module determines the fluorescence intensity variation curve at each point on the quantum sensing thin film based on the multiple fluorescence images, determines the magnetic field strength at each point based on the fluorescence intensity variation curve at each point, and determines the magnetic field strength distribution map sensed by the quantum sensing thin film based on the magnetic field strength at each point, thereby determining the parameter information of the magnetic particles in the sample to be tested based on the magnetic field strength distribution map.

[0013] According to some embodiments of this application, the data processing module determines the resonance frequency of the point based on the fluorescence intensity change curve, and determines the magnetic field strength based on the resonance frequency.

[0014] According to another aspect of this application, an electronic device is also provided. The electronic device includes: one or more processors; and a storage device for storing one or more programs, which, when executed by the one or more processors, enable the one or more processors to implement the detection method described above.

[0015] According to another aspect of this application, a non-volatile computer-readable storage medium is also provided. This storage medium stores a computer program that, when executed by a processor, can implement the detection method described above.

[0016] According to another aspect of this application, this application also provides a computer program product. The computer program product includes: a computer program stored on a computer-readable storage medium; the computer program includes program instructions that, when executed by a computer, cause the computer to perform the detection method described above.

[0017] Beneficial effects

[0018] This application provides a method for detecting magnetic particles, including applying an excitation light field to the side of a quantum sensing film near a substrate to excite a near-surface two-dimensional color center ensemble to generate a fluorescence signal; sequentially applying multiple microwave fields with different preset microwave frequencies to the quantum sensing film; and acquiring fluorescence images under each preset microwave frequency to obtain multiple fluorescence images. This application can also determine the fluorescence intensity variation curves at various points on the quantum sensing film based on the multiple fluorescence images; determine the magnetic field strength at each point based on the fluorescence intensity variation curves; and determine the magnetic field strength distribution map of the quantum sensing film based on the magnetic field strength at each point, thereby determining the parameter information of magnetic particles in the sample to be tested based on the magnetic field strength distribution map.

[0019] This application utilizes a quantum sensing thin film with a near-surface two-dimensional color center ensemble as a magnetic detection sensor, enabling the ensemble to closely approximate the magnetic particles in the sample. Furthermore, by systematically scanning microwave frequencies and monitoring the corresponding fluorescence response, the magnetic field strength distribution can be determined based on the fluorescence intensity change curve, thereby achieving the detection of magnetic particles. This application enables rapid detection of the sample, featuring fast detection, online detection capability, high real-time performance, and low cost. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A flowchart illustrating the method for detecting magnetic particles according to an embodiment of this application is shown. Figure 2 A schematic diagram showing fluorescence images of embodiments of this application; Figure 3A schematic diagram showing the fluorescence intensity change curve of an embodiment of this application; Figure 4 This diagram illustrates yet another flow chart of the method for detecting magnetic particles according to an embodiment of this application. Figure 5 This application shows a magnetic field strength distribution diagram according to an embodiment of the present application; Figure 6 A schematic diagram of a magnetic particle detection device according to an embodiment of this application is shown; Figure 7 A schematic diagram of a magnetic particle detection device according to an embodiment of this application is shown.

[0022] Explanation of reference numerals in the attached figures: Detection device 1; quantum sensing thin film 10; optical excitation module 20; microwave excitation module 30; imaging detection module 40; data processing module 50; Laser 21; Shaper 22; Dichroic mirror 23; Objective lens 24; Filter 60; Pipette module 70. Detailed Implementation

[0023] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this application will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted.

[0024] The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced without one or more of these specific details, or other methods, components, materials, devices, etc. In these cases, well-known structures, methods, devices, implementations, materials, or operations will not be shown or described in detail.

[0025] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0026] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order.

[0027] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] The inventors of this application have discovered that existing methods for detecting magnetic particles in batteries have at least the following problems: 1. Long testing cycle: From sample collection, magnetic enrichment, chemical processing to spectral analysis, the whole process usually takes 1-3 hours, which cannot meet the needs of rapid feedback on the production line.

[0029] 2. Inability to perform online testing: Current technology relies on offline laboratory testing, which is a sampling inspection model and cannot perform online testing.

[0030] 3. Delayed test results: Because the test is conducted offline, when the test results do not meet production requirements, the production line may have already been producing substandard products for several hours, resulting in serious waste of raw materials and economic losses.

[0031] According to one aspect of this application, this application provides a method for detecting magnetic particles in a sample to be tested (such as battery electrolyte).

[0032] Alternatively, the detection method can be performed by a detection device with computing capabilities.

[0033] According to an example embodiment, the quantum sensing thin film can be pre-fabricated. The quantum sensing thin film may include a substrate and a near-surface two-dimensional color center ensemble disposed on the substrate.

[0034] For example, a near-surface two-dimensional color center ensemble can be an aggregate of atomic-scale color centers (such as nitrogen-vacancy color centers) constructed at a predetermined depth below the surface of a substrate (such as solid transparent crystals like diamond or silicon carbide) through controlled doping and micro / nano fabrication techniques. Near-surface two-dimensional color center ensembles exhibit distinct two-dimensional planar characteristics.

[0035] Optionally, the near-surface two-dimensional color center ensemble can be prepared on the substrate by low-energy ion implantation or chemical vapor deposition, and this application does not limit this.

[0036] Optionally, the near-surface two-dimensional color center ensemble is located within a preset depth range on the surface of the quantum sensing thin film, which can be 2nm-20nm.

[0037] For example, the substrate can be diamond. For instance, by applying 5keV nitrogen ion implantation to the diamond surface, followed by high-temperature annealing and surface treatment, a near-surface two-dimensional color center ensemble with a predetermined depth range (e.g., 2nm-10nm) can be obtained. As another example, by placing diamond in a plasma-enhanced chemical vapor deposition apparatus, introducing a carbon source gas and a controllable nitrogen source gas, and precisely controlling growth parameters (e.g., temperature, pressure, gas ratio, nitrogen flow rate), nitrogen atoms can be in-situ incorporated into the diamond lattice as dopants, thus obtaining a near-surface two-dimensional nitrogen-vacancy color center ensemble with a predetermined depth range (e.g., 2nm-10nm).

[0038] Optionally, the quantum sensing thin film is made of at least one of diamond, hexagonal boron nitride, and silicon carbide. The near-surface two-dimensional color center ensemble includes at least one of nitrogen-vacancy color centers, silicon-vacancy color centers, boron-vacancy color centers, or other solid-state spin color centers formed by crystal defects.

[0039] For example, nitrogen-vacancy color centers have characteristics such as long spin coherence time and high sensitivity; silicon-vacancy color centers have characteristics such as narrow linewidth, high photon collection efficiency, and electrical controllability; and boron-vacancy color centers have characteristics such as atomically thin layers, flexible integration, and wide-band emission. This application allows for the selection of a suitable near-surface two-dimensional color center ensemble based on the temperature limitations of the detection environment, the required sensitivity, and the integration method.

[0040] According to an example embodiment, a near-surface two-dimensional color center ensemble is used to hold the sample to be tested.

[0041] For example, by placing the sample to be tested on the near-surface two-dimensional color center ensemble of the quantum sensing thin film, the magnetic particles in the sample to be tested can be brought closer to the near-surface two-dimensional color center ensemble.

[0042] This application uses a quantum sensing thin film with a near-surface two-dimensional color center ensemble as a magnetic detection sensor, which allows the near-surface two-dimensional color center ensemble to be closer to the magnetic particles in the sample. Since the field strength signal of the magnetic particles is negatively correlated with the distance to the magnetic detection sensor, this application can solve the problem of not being able to detect weak magnetic particles by setting the near-surface two-dimensional color center ensemble, thus ensuring detection accuracy.

[0043] Figure 1 A schematic flowchart illustrating the method for detecting magnetic particles according to an embodiment of this application is shown.

[0044] According to the example embodiment, such as Figure 1 As shown, the detection method may include steps S100-S600.

[0045] According to the example embodiment, in step S100, the detection device applies an excitation light field to the side of the quantum sensing film near the substrate to excite the near-surface two-dimensional color center ensemble to generate a fluorescence signal.

[0046] For example, the detection device can apply an excitation light field to the quantum sensing film. The laser signal can be incident from the side of the quantum sensing film near the substrate, and applied to the near-surface two-dimensional color center ensemble through the substrate to spin polarize and excite the near-surface two-dimensional color center ensemble, thereby generating a fluorescence signal.

[0047] It is understandable that when the sample is placed on a near-surface two-dimensional color center ensemble, the magnetic particles in the sample will affect the electric dipole moment of the electrons in the lower color center, resulting in a decrease in fluorescence efficiency and a plasmonic enhancement effect. Furthermore, the magnetic particles themselves have a scattering or reflection effect on the incident laser signal, which will also significantly affect the imaging light intensity at their location.

[0048] Since the sample to be measured is carried on the near-surface two-dimensional color center ensemble, by incident a laser signal on the side of the quantum sensing film closer to the substrate, the magnetic particles in the sample to be measured on the near-surface two-dimensional color center ensemble can avoid blocking the laser signal. This avoids problems such as unbalanced spin polarization and differences in sensing signals caused by non-uniform excitation light field in quantum sensing films.

[0049] Figure 2 A schematic diagram showing fluorescence images of embodiments of this application; Figure 3 A schematic diagram showing the fluorescence intensity change curve of an embodiment of this application; Figure 4 This diagram illustrates yet another flow chart of the method for detecting magnetic particles according to an embodiment of this application. Figure 5 The magnetic field strength distribution diagram of an embodiment of this application is shown.

[0050] In step S200, the detection device sequentially applies microwave fields with different preset microwave frequencies to the quantum sensing film.

[0051] In step S300, the detection device acquires fluorescence images under a microwave field at each preset microwave frequency to obtain multiple fluorescence images.

[0052] For example, such as Figure 2 As shown, the detection device acquires fluorescence images under a microwave field at each preset microwave frequency.

[0053] For example, such as Figure 2 As shown, in the XY coordinate system, the fluorescence image can include the fluorescence intensity and coordinate information (X, Y) of each point on the quantum sensing thin film.

[0054] Optionally, the detection device can achieve spectral scanning detection of the magnetic field of the sample under test by sequentially applying microwave fields of different frequencies to the quantum sensing thin film.

[0055] Optionally, the detection device can acquire multiple fluorescence images using a multi-pixel wide-field imaging system or a scanning microscopy imaging system.

[0056] For example, multi-pixel wide-field imaging systems include, but are not limited to, CCD (Charge-Coupled Device Camera), CMOS (Complementary Metal-Oxide-Semiconductor) cameras, and MPPC (Multi-Pixel Photo-detector) wide-field imaging devices. Scanning microscopy imaging systems include, but are not limited to, single-pixel PD (Photo-diode) or APD (Avalanche Photo-diode), and this application does not limit them.

[0057] Multi-pixel wide-field imaging systems offer rapid and global imaging capabilities, while scanning microscopy systems provide high-resolution imaging. This application utilizes either a multi-pixel wide-field imaging system or a scanning microscopy system to ensure image quality, thereby guaranteeing the accuracy of magnetic particle detection.

[0058] In step S400, the detection device determines the fluorescence intensity change curves at various points on the quantum sensing film based on multiple fluorescence images.

[0059] For example, by systematically scanning microwave frequencies and monitoring the corresponding fluorescence response (which can be represented by each fluorescence image), the detection device can obtain the fluorescence intensity change curve corresponding to each point.

[0060] For example, such as Figure 3 As shown, Figure 3 The figure shows the fluorescence intensity variation curves of magnetic particles with different magnetic sizes (0G, 15G, 30G and 40G, respectively).

[0061] In step S500, the detection device determines the magnetic field strength at each point based on the fluorescence intensity change curve at each point.

[0062] For example, the magnetic field generated by magnetic particles in the sample under test can cause the Zeeman effect in the spin of electrons in the lower color center. The near-surface two-dimensional color center ensemble in the quantum sensing thin film has a specific spin resonance frequency, which can be shifted by changes in the local magnetic field (Zeeeman effect).

[0063] The detection device can calculate and analyze the magnetic field by measuring the fluorescence intensity change curve of the quantum sensing thin film using the Hamiltonian (Zeeman split), thereby determining the magnetic field strength at each point under the influence of magnetic particles.

[0064] Optionally, such as Figure 4 As shown, step S500 may also include steps S510-S520.

[0065] In step S510, the detection device determines the resonance frequency of the location based on the fluorescence intensity change curve.

[0066] In step S520, the detection device determines the magnetic field strength based on the resonant frequency.

[0067] For example, such as Figure 3 As shown, the detection device can determine the resonant frequency at a given point based on the fluorescence intensity change curve (e.g., Figure 3 As shown in the low peak of the image), the detection device can calculate the magnetic field strength at that point by inverting the relationship between the resonant frequency and the magnetic field strength.

[0068] In step S600, the detection device determines the magnetic field intensity distribution map sensed by the quantum sensing film based on the magnetic field intensity at each point, so as to determine the parameter information of the magnetic particles in the sample to be tested based on the magnetic field intensity distribution map.

[0069] For example, such as Figure 5 As shown, the detection device can determine the magnetic field intensity distribution at all points under the influence of magnetic particles. Based on this magnetic field intensity distribution, the detection device can analyze and obtain the parameter information of all magnetic particles.

[0070] Optionally, the parameter information includes, but is not limited to, information on the type, position, and size of the magnetic particles, and this application does not impose any restrictions on this.

[0071] For example, since the saturation magnetization of different magnetic particles varies significantly (e.g., the saturation magnetization of iron particles is 1.714 MA / m, that of cobalt particles is 1.422 MA / m, and that of nickel particles is 0.482 MA / m), the detection device can determine the gradient magnetic field information of the existing magnetic particles using a magnetic field intensity distribution map, and thus determine the type of magnetic particle based on this gradient magnetic field information. The detection device can also determine the position and size information of the magnetic particles using the XY axis coordinate information in the magnetic field intensity distribution map.

[0072] Optionally, the sample to be tested is a battery electrolyte, and the magnetic particles include at least one of the following metal particles: lithium, iron, copper, nickel, cobalt, and aluminum.

[0073] For example, the application scenario of the technical solution of this application is the detection of magnetic impurities in the manufacturing process of batteries (such as lithium-ion batteries). The sample to be tested is the battery electrolyte, which can be sampled by a pipette and placed on a quantum sensing thin film, thereby enabling rapid detection of magnetic impurities in the battery electrolyte.

[0074] This application enables rapid detection of magnetic particles in battery electrolytes, rapid analysis of the parameters of magnetic particles, and rapid traceability of production quality problems during battery manufacturing.

[0075] Through the above embodiments, this application provides a method for detecting magnetic particles, including applying an excitation light field to the side of a quantum sensing film near a substrate to excite a near-surface two-dimensional color center ensemble to generate a fluorescence signal; sequentially applying multiple microwave fields with different preset microwave frequencies to the quantum sensing film; and acquiring fluorescence images under each preset microwave frequency microwave field to obtain multiple fluorescence images. This application can also determine the fluorescence intensity variation curves at various points on the quantum sensing film based on the multiple fluorescence images; determine the magnetic field strength at each point based on the fluorescence intensity variation curves at each point; and determine the magnetic field strength distribution map of the quantum sensing film based on the magnetic field strength at each point, so as to determine the parameter information of magnetic particles in the sample to be tested based on the magnetic field strength distribution map.

[0076] This application utilizes a quantum sensing thin film with a near-surface two-dimensional color center ensemble as a magnetic detection sensor, enabling the ensemble to closely approximate the magnetic particles in the sample. Furthermore, by systematically scanning microwave frequencies and monitoring the corresponding fluorescence response, the magnetic field strength distribution can be determined based on the fluorescence intensity change curve, thereby achieving the detection of magnetic particles. This application enables rapid detection of the sample, featuring fast detection, online detection capability, high real-time performance, and low cost.

[0077] According to another aspect of this application, this application also provides a magnetic particle detection device for detecting magnetic particles in a sample to be tested (such as battery electrolyte).

[0078] Figure 6 A schematic diagram of a magnetic particle detection device according to an embodiment of this application is shown; Figure 7 A schematic diagram of a magnetic particle detection device according to an embodiment of this application is shown.

[0079] According to the example embodiment, such as Figure 6 As shown, the detection device 1 may include a quantum sensing thin film 10, an optical excitation module 20, a microwave excitation module 30, an imaging detection module 40, and a data processing module 50.

[0080] According to an example embodiment, the quantum sensing film 10 can be pre-prepared. The quantum sensing film 10 may include a substrate and a near-surface two-dimensional color center ensemble disposed on the substrate.

[0081] For example, a near-surface two-dimensional color center ensemble can be an aggregate of atomic-scale color centers (such as nitrogen-vacancy color centers) constructed at a predetermined depth below the surface of a substrate (such as solid transparent crystals like diamond or silicon carbide) through controlled doping and micro / nano fabrication techniques. Near-surface two-dimensional color center ensembles exhibit distinct two-dimensional planar characteristics.

[0082] Optionally, the near-surface two-dimensional color center ensemble can be prepared on the substrate by low-energy ion implantation or chemical vapor deposition, and this application does not limit this.

[0083] Optionally, the near-surface two-dimensional color center ensemble is located within a preset depth range on the surface of the quantum sensing thin film 10, which can be 2nm-20nm.

[0084] For example, the substrate can be diamond. For instance, by applying 5keV nitrogen ion implantation to the diamond surface, followed by high-temperature annealing and surface treatment, a near-surface two-dimensional color center ensemble with a predetermined depth range (e.g., 2nm-10nm) can be obtained. As another example, by placing diamond in a plasma-enhanced chemical vapor deposition apparatus, introducing a carbon source gas and a controllable nitrogen source gas, and precisely controlling growth parameters (e.g., temperature, pressure, gas ratio, nitrogen flow rate), nitrogen atoms can be in-situ incorporated into the diamond lattice as dopants, resulting in a near-surface nitrogen-vacancy two-dimensional color center ensemble with a predetermined depth range (e.g., 2nm-10nm).

[0085] Optionally, the quantum sensing thin film 10 is made of at least one of diamond, hexagonal boron nitride, and silicon carbide. The near-surface two-dimensional color center ensemble includes at least one of nitrogen-vacancy color centers, silicon-vacancy color centers, boron-vacancy color centers, or other solid-state spin color centers formed by crystal defects.

[0086] For example, nitrogen-vacancy color centers have characteristics such as long spin coherence time and high sensitivity; silicon-vacancy color centers have characteristics such as narrow linewidth, high photon collection efficiency, and electrical controllability; and boron-vacancy color centers have characteristics such as atomically thin layers, flexible integration, and wide-band emission. This application allows for the selection of a suitable near-surface two-dimensional color center ensemble based on the temperature limitations of the detection environment, the required sensitivity, and the integration method.

[0087] According to an example embodiment, a near-surface two-dimensional color center ensemble is used to hold the sample to be tested.

[0088] For example, by placing the sample to be tested on the near-surface two-dimensional color center ensemble of the quantum sensing thin film 10, the magnetic particles in the sample to be tested can be made to be closer to the near-surface two-dimensional color center ensemble.

[0089] This application uses a quantum sensing thin film with a near-surface two-dimensional color center ensemble as a magnetic detection sensor, which allows the near-surface two-dimensional color center ensemble to be closer to the magnetic particles in the sample. Since the field strength signal of the magnetic particles is negatively correlated with the distance to the magnetic detection sensor, this application can solve the problem of not being able to detect weak magnetic particles by setting the near-surface two-dimensional color center ensemble, thus ensuring detection accuracy.

[0090] According to an example embodiment, the optical excitation module 20 applies an excitation light field to the side of the quantum sensing film near the substrate to excite the near-surface two-dimensional color center ensemble to generate a fluorescence signal.

[0091] For example, the optical excitation module 20 can apply an excitation light field to the quantum sensing film. The laser signal can be incident from the side of the quantum sensing film 10 near the substrate, and applied to the near-surface two-dimensional color center ensemble through the substrate to spin polarize and excite the near-surface two-dimensional color center ensemble, thereby generating a fluorescence signal.

[0092] It is understandable that when the sample is placed on a near-surface two-dimensional color center ensemble, the magnetic particles in the sample will affect the electric dipole moment of the electrons in the lower color center, resulting in a decrease in fluorescence efficiency and a plasmonic enhancement effect. Furthermore, the magnetic particles themselves have a scattering or reflection effect on the incident laser signal, which will also significantly affect the imaging light intensity at their location.

[0093] Since the sample to be tested is carried on the near-surface two-dimensional color center ensemble, by incident a laser signal on the side of the quantum sensing film 10 close to the substrate, the magnetic particles in the sample to be tested on the near-surface two-dimensional color center ensemble can avoid blocking the laser signal, thereby avoiding problems such as unbalanced spin polarization and differences in sensing signals caused by non-uniform excitation light field in the quantum sensing film 10.

[0094] Optionally, such as Figure 7 As shown, the optical excitation module 21 may include a laser 21, a shaper 22, a dichroic mirror 23, and an objective lens 24.

[0095] For example, such as Figure 7 As shown, laser 21 emits a Gaussian laser, and shaper 22 (such as a lens, engineering diffuser, or flat-top light shaper) receives the Gaussian laser and shapes it into a uniformly divergent laser. After being reflected by dichroic mirror 23, the laser passes through objective lens 24 to form a uniform light field at its focal plane. Finally, this uniform light field is incident on the quantum sensing film 10 from the side of the quantum sensing film 10 closest to the substrate.

[0096] Optionally, such as Figure 7As shown, the detection device 1 may also include a pipetting module 70, through which the sample to be tested can be placed on the quantum sensing film 10.

[0097] like Figure 7 As shown, the microwave excitation module 30 sequentially applies microwave fields with different preset microwave frequencies to the quantum sensing film 10. The imaging detection module 40 acquires fluorescence images under each preset microwave frequency microwave field to obtain multiple fluorescence images.

[0098] For example, such as Figure 2 As shown, the imaging detection module 40 acquires fluorescence images under a microwave field at each preset microwave frequency.

[0099] For example, such as Figure 2 As shown, in the XY coordinate system, the fluorescence image can include the fluorescence intensity and coordinate information (X, Y) of each point on the quantum sensing film 10.

[0100] Optionally, the microwave excitation module 30 can sequentially apply microwave fields of different frequencies to the quantum sensing film to realize the spectral scanning detection of the magnetic field of the sample under test.

[0101] Optionally, a filter 60 may be provided between the dichroic mirror 23 and the imaging detection module 40.

[0102] Optionally, the imaging detection module 40 can acquire multiple fluorescence images through a multi-pixel wide-field imaging system or a scanning microscopy imaging system.

[0103] For example, multi-pixel wide-field imaging systems include, but are not limited to, CCD (Charge-Coupled Device Camera), CMOS (Complementary Metal-Oxide-Semiconductor) cameras, and MPPC (Multi-Pixel Photo-detector) wide-field imaging devices. Scanning microscopy imaging systems include, but are not limited to, single-pixel PD (Photo-diode) or APD (Avalanche Photo-diode), and this application does not limit them.

[0104] Multi-pixel wide-field imaging systems offer rapid and global imaging capabilities, while scanning microscopy systems provide high-resolution imaging. This application utilizes either a multi-pixel wide-field imaging system or a scanning microscopy system to ensure image quality, thereby guaranteeing the accuracy of magnetic particle detection.

[0105] The data processing module 50 determines the fluorescence intensity change curves at various points on the quantum sensing thin film based on multiple fluorescence images.

[0106] For example, by systematically scanning the microwave frequency and monitoring the corresponding fluorescence response (which can be represented by each fluorescence image), the data processing module 50 can obtain the fluorescence intensity change curve corresponding to each point.

[0107] For example, such as Figure 3 As shown, Figure 3 The figure shows the fluorescence intensity variation curves of magnetic particles with different magnetic sizes (0G, 15G, 30G and 40G, respectively).

[0108] The data processing module 50 determines the magnetic field strength at each point based on the fluorescence intensity change curve at each point.

[0109] For example, the magnetic field generated by magnetic particles in the sample under test can cause the Zeeman effect to occur in the electron spin of the lower color center. The near-surface two-dimensional color center ensemble in the quantum sensing thin film 10 has a specific spin resonance frequency, which will shift due to changes in the local magnetic field (Zeeeman effect).

[0110] The data processing module 50 can perform magnetic field calculation and analysis on the fluorescence intensity change curve through the Hamiltonian (Zeman split) of the quantum sensing thin film, thereby determining the magnetic field strength of each point under the influence of magnetic particles.

[0111] Optionally, the data processing module 50 determines the resonant frequency of the location based on the fluorescence intensity change curve. The data processing module 50 then determines the magnetic field strength based on the resonant frequency.

[0112] For example, such as Figure 3 As shown, the data processing module 50 can determine the resonance frequency at that point based on the fluorescence intensity change curve (e.g., Figure 3 As shown in the low peak of the data (the data processing module 50 can calculate the magnetic field strength at that point by inverting the physical relationship between the resonance frequency and the magnetic field strength), the data processing module 50.

[0113] The data processing module 50 determines the magnetic field intensity distribution map sensed by the quantum sensing film based on the magnetic field intensity at each point, and then determines the parameter information of the magnetic particles in the sample to be tested based on the magnetic field intensity distribution map.

[0114] For example, such as Figure 5 As shown, the data processing module 50 can determine the magnetic field intensity distribution map of all points under the influence of magnetic particles. Based on this magnetic field intensity distribution map, the data processing module 50 can analyze and obtain the parameter information of all magnetic particles.

[0115] Optionally, the parameter information includes, but is not limited to, information on the type, position, and size of the magnetic particles, and this application does not impose any restrictions on this.

[0116] For example, since the saturation magnetization of different magnetic particles varies significantly (e.g., the saturation magnetization of iron particles is 1.714 MA / m, that of cobalt particles is 1.422 MA / m, and that of nickel particles is 0.482 MA / m), the data processing module 50 can determine the gradient magnetic field information of the existing magnetic particles through the magnetic field intensity distribution map, and thus determine the type of magnetic particle based on this gradient magnetic field information. The data processing module 50 can also determine the position and size information of the magnetic particles through the XY axis coordinate information in the magnetic field intensity distribution map.

[0117] Optionally, the sample to be tested is a battery electrolyte, and the magnetic particles include at least one of the following metal particles: lithium, iron, copper, nickel, cobalt, and aluminum.

[0118] For example, the application scenario of the technical solution of this application is the detection of magnetic impurities in the manufacturing process of batteries (such as lithium-ion batteries). The sample to be tested is the battery electrolyte, which can be sampled by a pipette and placed on a quantum sensing thin film, thereby enabling rapid detection of magnetic impurities in the battery electrolyte.

[0119] This application enables rapid detection of magnetic particles in battery electrolytes, rapid analysis of the parameters of magnetic particles, and rapid traceability of production quality problems during battery manufacturing.

[0120] This application utilizes a quantum sensing thin film with a near-surface two-dimensional color center ensemble as a magnetic detection sensor, enabling the ensemble to closely approximate the magnetic particles in the sample. Furthermore, by systematically scanning microwave frequencies and monitoring the corresponding fluorescence response, the magnetic field strength distribution can be determined based on the fluorescence intensity change curve, thereby achieving the detection of magnetic particles. This application enables rapid detection of the sample, featuring fast detection, online detection capability, high real-time performance, and low cost.

[0121] According to another aspect of this application, an electronic device is also provided. The electronic device includes: one or more processors; and a storage device for storing one or more programs, which, when executed by the one or more processors, enable the one or more processors to implement the detection method described above.

[0122] According to another aspect of this application, a non-volatile computer-readable storage medium is also provided. This storage medium stores a computer program that, when executed by a processor, can implement the detection method described above.

[0123] According to another aspect of this application, this application also provides a computer program product. The computer program product includes: a computer program stored on a computer-readable storage medium; the computer program includes program instructions that, when executed by a computer, cause the computer to perform the detection method described above.

[0124] Finally, it should be noted that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions of the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for detecting magnetic particles, characterized in that, The quantum sensing thin film includes a substrate and a near-surface two-dimensional color center ensemble disposed on the substrate, the near-surface two-dimensional color center ensemble being used to carry the sample to be tested, and the detection method includes: An excitation light field is applied to the side of the quantum sensing film near the substrate to excite the near-surface two-dimensional color center ensemble to generate a fluorescence signal; Multiple microwave fields with different preset microwave frequencies are sequentially applied to the quantum sensing thin film; Fluorescence images are acquired under a microwave field at each preset microwave frequency to obtain multiple fluorescence images; The fluorescence intensity variation curves at various points of the quantum sensing thin film are determined based on the multiple fluorescence images. The magnetic field strength at each of the points is determined based on the fluorescence intensity change curve at each point. The magnetic field intensity distribution map sensed by the quantum sensing film is determined based on the magnetic field intensity at each of the said points, and the parameter information of the magnetic particles in the sample to be tested is determined based on the magnetic field intensity distribution map.

2. The detection method according to claim 1, characterized in that, The step of determining the magnetic field strength at each of the said locations based on the fluorescence intensity change curves at each location includes: The resonance frequency of the point is determined based on the fluorescence intensity change curve; The magnetic field strength is determined based on the resonant frequency.

3. The detection method according to claim 1, characterized in that, The acquisition of fluorescence images under a microwave field at each preset microwave frequency to obtain multiple fluorescence images includes: The multiple fluorescence images are acquired using a multi-pixel wide-field imaging system or a scanning microscopy system.

4. The detection method according to claim 1, characterized in that, The sample to be tested is battery electrolyte; The magnetic particles include at least one of the following metallic particles: lithium, iron, copper, nickel, cobalt, and aluminum.

5. The detection method according to claim 1, characterized in that, The quantum sensing film is made of at least one of diamond, hexagonal boron nitride, and silicon carbide; The near-surface two-dimensional color center ensemble includes at least one of nitrogen-vacancy color centers, silicon-vacancy color centers, boron-vacancy color centers, or other solid-state spin color centers formed by crystal defects.

6. The detection method according to claim 1, characterized in that, The near-surface two-dimensional color center ensemble is located within a predetermined depth range on the surface of the quantum sensing thin film; The preset depth range is 2nm-20nm.

7. A device for detecting magnetic particles, characterized in that, The detection device is used to perform the detection method as described in any one of claims 1-6, and the detection device comprises: A quantum sensing thin film includes a substrate and a near-surface two-dimensional color center ensemble disposed on the substrate, the near-surface two-dimensional color center ensemble being used to carry the sample to be measured; An optical excitation module applies an excitation light field to the side of the quantum sensing film near the substrate to excite the near-surface two-dimensional color center ensemble to generate a fluorescence signal; The microwave excitation module sequentially applies multiple microwave fields with different preset microwave frequencies to the quantum sensing thin film. The imaging detection module acquires fluorescence images under a microwave field at each preset microwave frequency to obtain multiple fluorescence images; The data processing module determines the fluorescence intensity change curves of each point on the quantum sensing film based on the multiple fluorescence images, determines the magnetic field strength of each point based on the fluorescence intensity change curves of each point, and determines the magnetic field strength distribution map sensed by the quantum sensing film based on the magnetic field strength of each point, so as to determine the parameter information of the magnetic particles in the sample to be tested based on the magnetic field strength distribution map.

8. The detection device according to claim 7, characterized in that, The data processing module determines the resonance frequency of the point based on the fluorescence intensity change curve, and determines the magnetic field strength based on the resonance frequency.

9. An electronic device, characterized in that, include: One or more processors; Storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the detection method as described in any one of claims 1-6.

10. A non-volatile computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the detection method as described in any one of claims 1-6.

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