Real-time micro-plastic detection method and device, computer equipment and storage medium

Abstract

The embodiment of the invention belongs to the technical field of optical fiber sensors, and relates to a micro-plastic real-time detection method and device, computer equipment and a storage medium, and the method comprises the following steps: after a to-be-detected sample is put into a liquid storage tank provided with an inclined grating, obtaining real-time spectral data collected by a spectrograph; calculating grating spectrum data according to the sample spectrum data and the light source spectrum data; performing spectrum trough identification operation on the grating spectrum data to obtain grating trough data; performing spectrum SPR response identification operation on the grating trough data to obtain SPR wavelength data; performing drawing operation according to the SPR wavelength data to obtain a real-time detection result of the micro-plastic; and outputting the real-time detection result of the micro-plastic. The invention provides a faster and more efficient detection system in a tilted fiber grating-plasma resonance detection system, and provides an innovative solution for the fields of biosensing, chemical analysis, environmental monitoring and the like.

Description

Technical Field

[0001] This application relates to the technical field of fiber optic sensors, and particularly to a method, device, computer equipment and storage medium for real-time detection of microplastics. Background Art

[0002] Fiber Bragg grating technology has been highly favored due to its high sensitivity, tunability and real-time monitoring capabilities. The tilted fiber Bragg grating (hereinafter referred to as the tilted fiber Bragg grating) is a type of fiber Bragg grating, and its characteristic lies in that its periodically varying refractive index structure is not perpendicular to the optical axis, but forms an angle. It has been applied in multiple fields, such as environmental monitoring, structural health monitoring, biosensing and chemical analysis. The design and preparation methods of the tilted fiber Bragg grating are also constantly improving to meet the requirements of different application fields, making it a highly potential detection tool.

[0003] Plasmon resonance is another remarkable optical phenomenon and is of great significance in the fields of optics and photonics. Plasmon resonance involves the collective oscillation of electrons on the surface of metals or semiconductors, resulting in the absorption or scattering of light with a specific wavelength by the surface, thus generating a resonance phenomenon. This phenomenon plays a key role in surface-enhanced spectroscopy, sensing and detection. The application scope of plasmon resonance is very wide, including fields such as biosensing, chemical analysis, environmental monitoring and materials science.

[0004] Plasmon resonance can be excited by a grating, and this characteristic enables the advantages of the tilted fiber Bragg grating and plasmon to be combined together. Researchers have explored a tilted fiber Bragg grating - plasmon resonance detection system. Such a system can achieve highly sensitive detection, monitor trace analysis substances, or detect the presence of biomolecules. This provides a revolutionary solution for fields such as biomedical diagnosis, environmental monitoring, food safety, etc.

[0005] Meanwhile, in recent years, environmental problems have become increasingly severe, and various emerging pollutants have emerged in an endless stream. Among them, the non-degradable pollutants represented by microplastics pose an increasingly severe threat to the ecological environment. However, there is no application method for real-time and accurate detection of microplastics at the present stage. Summary of the Invention

[0006] The purpose of the embodiments of this application is to propose a method, device, computer equipment and storage medium for real-time detection of microplastics to solve the problem that there is no real-time and accurate detection method for microplastics at the present stage.

[0007] To solve the above technical problems, an embodiment of the present application provides a method for real-time detection of microplastics. The method is applied to an inclined fiber Bragg grating SPR detection system. The inclined fiber Bragg grating SPR detection system includes: a broadband light source, an optical fiber polarizer, a polarization controller, a liquid storage tank provided with an inclined grating, and a spectrometer. The method adopts the following technical solutions:

[0008] After the sample to be detected is placed in the liquid storage tank provided with the inclined grating, real-time spectral data collected by the spectrometer is obtained. The real-time spectral data includes sample spectral data and light source spectral data.

[0009] Calculate grating spectral data based on the sample spectral data and the light source spectral data.

[0010] Perform a spectral valley identification operation on the grating spectral data to obtain grating valley data.

[0011] Perform a spectral SPR response identification operation on the grating valley data to obtain SPR wavelength data.

[0012] Perform a drawing operation based on the SPR wavelength data to obtain the real-time detection result of microplastics.

[0013] Output the real-time detection result of microplastics.

[0014] Further, after the step of calculating grating spectral data based on the sample spectral data and the light source spectral data, and before the step of performing a spectral valley identification operation on the grating spectral data to obtain grating valley data, the following steps are further included:

[0015] Perform smoothing processing on the grating spectral data.

[0016] Further, the step of performing a spectral valley identification operation on the grating spectral data to obtain grating valley data specifically includes the following steps:

[0017] Identify the valleys of the grating spectral data according to the signal.find_peaks() method to obtain the grating valley data.

[0018] Further, the step of performing a spectral SPR response identification operation on the grating valley data to obtain SPR wavelength data specifically includes the following steps:

[0019] Obtain a preset sliding window, and perform Gaussian fitting operation on the grating valley data according to the sliding window to obtain valleys affected by SPR.

[0020] Calculate the wavelength mean of the valleys affected by SPR to obtain the SPR wavelength data.

[0021] Further, the light source wavelength range of the broadband light source is 1370 nm to 1700 nm, and the power is 50 μW.

[0022] Further, the inclination parameter of the tilted grating is 10°, the Bragg wavelength is 1550 nm, and the spectral range of the cladding resonance peak of the tilted grating is 1480 nm to 1550 nm.

[0023] Further, the spectral range of the fiber optic polarizer is 1430 nm to 1530 nm.

[0024] To solve the above technical problems, an embodiment of the present application further provides a microplastic real-time detection device, which is applied to a tilted fiber grating SPR detection system. Among them, the tilted fiber grating SPR detection system includes: a broadband light source, a fiber optic polarizer, a polarization controller, a liquid storage tank provided with a tilted grating, and a spectrometer. The device adopts the following technical solutions:

[0025] A real-time spectrum acquisition module, configured to acquire real-time spectrum data collected by the spectrometer after a sample to be detected is placed in the liquid storage tank provided with the tilted grating. Among them, the real-time spectrum data includes sample spectrum data and light source spectrum data;

[0026] A grating spectrum calculation module, configured to calculate grating spectrum data according to the sample spectrum data and the light source spectrum data;

[0027] A spectral wave valley identification module, configured to perform a spectral wave valley identification operation on the grating spectrum data to obtain grating wave valley data;

[0028] A spectral SPR response identification module, configured to perform a spectral SPR response identification operation on the grating wave valley data to obtain SPR wavelength data;

[0029] A plotting module, configured to perform a plotting operation according to the SPR wavelength data to obtain a microplastic real-time detection result;

[0030] An output module, configured to output the microplastic real-time detection result.

[0031] To solve the above technical problems, an embodiment of the present application further provides a computer device, which adopts the following technical solutions:

[0032] It includes a memory and a processor. Computer-readable instructions are stored in the memory. When the processor executes the computer-readable instructions, the steps of the above-mentioned microplastic real-time detection method are implemented.

[0033] To solve the above technical problems, an embodiment of the present application further provides a computer-readable storage medium, adopting the following technical solutions:

[0034] Computer-readable instructions are stored on the computer-readable storage medium, and when the computer-readable instructions are executed by a processor, the steps of the above-mentioned real-time microplastic detection method are implemented.

[0035] The present application provides a real-time microplastic detection method, which is applied to an inclined fiber Bragg grating SPR detection system. Among them, the inclined fiber Bragg grating SPR detection system includes: a broadband light source, a fiber optic polarizer, a polarization controller, a liquid storage tank provided with an inclined grating, and a spectrometer, including: after the sample to be detected is placed in the liquid storage tank provided with the inclined grating, acquiring the real-time spectral data collected by the spectrometer, where the real-time spectral data includes sample spectral data and light source spectral data; calculating grating spectral data according to the sample spectral data and the light source spectral data; performing a spectral valley identification operation on the grating spectral data to obtain grating valley data; performing a spectral SPR response identification operation on the grating valley data to obtain SPR wavelength data; performing a plotting operation according to the SPR wavelength data to obtain a real-time microplastic detection result; outputting the real-time microplastic detection result. Compared with the prior art, the present application provides a more rapid and efficient detection system in the inclined fiber Bragg grating - surface plasmon resonance detection system, bringing an innovative solution to the fields of biosensing, chemical analysis, environmental monitoring, etc. Description of the Drawings

[0036] To more clearly illustrate the solutions in the present application, the following will briefly introduce the drawings required for the description of the embodiments of the present application. Obviously, the following drawings are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0037] Figure 1 is an exemplary system architecture diagram to which the present application can be applied;

[0038] Figure 2 is a flowchart of the implementation of the real-time microplastic detection method provided by the embodiment of the present application;

[0039] Figure 3 is a schematic structural diagram of the inclined fiber Bragg grating SPR detection system provided by the embodiment of the present application;

[0040] Figure 4 is an effect diagram before and after median filtering provided by the embodiment of the present application;

[0041] Figure 5It is the effect diagram before and after peak finding provided by the embodiment of the present application;

[0042] Figure 6 It is the Gaussian fitting effect diagram provided by the embodiment of the present application;

[0043] Figure 7 It is the real-time analysis diagram provided by the embodiment of the present application;

[0044] Figure 8 It is a schematic diagram of the change image of the SPR wavelength and particle size of the polystyrene suspension provided by the embodiment of the present application;

[0045] Figure 9 It is a schematic diagram of the change image of the SPR wavelength and concentration of the polystyrene suspension provided by the embodiment of the present application;

[0046] Figure 10 It is a schematic structural diagram of the microplastic real-time detection device provided by the embodiment of the present application;

[0047] Figure 11 It is a schematic structural diagram of an embodiment of a computer device according to the present application. Detailed implementation manners

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of this application or the above drawings are used to distinguish different objects and not to describe a specific order.

[0049] Referring to "embodiment" herein means that a specific feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0050] In order to enable those skilled in the art of this technology to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the drawings.

[0051] Such as Figure 1As shown, the system architecture 100 may include a terminal device 101, a network 102, and a server 103. The terminal device 101 may be a laptop computer 1011, a tablet computer 1012, or a mobile phone 1013. The network 102 is a medium for providing a communication link between the terminal device 101 and the server 103. The network 102 may include various connection types, such as wired, wireless communication links, or fiber optic cables, etc.

[0052] Users can use the terminal device 101 to interact with the server 103 through the network 102 to receive or send messages, etc. Various communication client applications may be installed on the terminal device 101, such as a web browser application, a shopping application, a search application, an instant messaging tool, an email client, a social platform software, etc.

[0053] The terminal device 101 may be various electronic devices with a display screen and supporting web browsing. In addition to the laptop computer 1011, the tablet computer 1012, or the mobile phone 1013, the terminal device 101 may also be an e-book reader, an MP3 player (Moving Picture Experts Group Audio Layer III), an MP4 (Moving Picture Experts Group Audio Layer IV) player, a laptop portable computer, a desktop computer, etc.

[0054] The server 103 may be a server providing various services, such as a background server supporting the pages displayed on the terminal device 101.

[0055] It should be noted that the microplastic real-time detection method provided by the embodiments of the present application is generally executed by the server / terminal device. Correspondingly, the microplastic real-time detection device is generally disposed in the server / terminal device.

[0056] It should be understood that Figure 1 the numbers of the terminal device, the network, and the server in

[0057] Continue to refer to Figure 2 , which shows a flowchart of an embodiment of the microplastic real-time detection method according to the present application. The microplastic real-time detection method is applied to a tilted fiber Bragg grating SPR detection system. The tilted fiber Bragg grating SPR detection system includes: a broadband light source, a fiber optic polarizer, a polarization controller, a liquid storage tank provided with a tilted grating, and a spectrometer. The method includes: step S201, step S202, step S203, step S204, step S205, and step S206.

[0058] In the embodiments of the present application, referring to Figure 3 the structural schematic diagram of the tilted fiber Bragg grating SPR detection system shown in the figure, on the left is the fiber Bragg grating SPR detection system, which is the optical detection module responsible for completing the detection of actual samples through the TFBG-SPR principle and providing the most original experimental data for the upper-layer module. On the right is the control and data processing system, which is responsible for controlling the TFBG-SPR detection system to complete the detection task, receiving real-time experimental data for rapid subsequent processing, and storing the results, where:

[0059] In the embodiments of the present application, the Yokogawa broad-spectrum light source (AQ6370C) is used in the present application. The broad-spectrum light source has a relatively wide spectral bandwidth, can provide light of various wavelengths, and can cover the visible light and even the infrared or ultraviolet spectral bands. The wavelength range of this light source is 1370 - 1700 nm, and the power is about 50 μW. The spectrometer is Yokogawa AQ6370C.

[0060] In the embodiments of the present application, since when exciting the SPR phenomenon, the incident light needs to resonate with the surface plasmon wave propagating along the metal-dielectric surface, only the P-polarized light in the tilted fiber Bragg grating can respond. Therefore, a polarizer must be used in the system. The tilt angle parameter of the tilted grating used in the present application is 10°, the Bragg wavelength is 1550 nm, and the spectral range of its cladding resonance peak is between 1480 - 1550 nm. In this study, an optical fiber polarizer with a spectral range of 1480 ± 50 nm is selected.

[0061] In the embodiments of the present application, the tilted fiber Bragg grating is gold-plated and used as a sensitive element to sense the concentration change of the liquid to be measured (microplastic bead suspension).

[0062] In the embodiments of the present application, the sample cell for the liquid to be measured is a specially prepared solution cell, and the material is polytetrafluoroethylene.

[0063] In the embodiments of the present application, the tilted fiber Bragg grating structure is selected for this system because the light of the tilted fiber Bragg grating has the following advantages compared with the ordinary fiber structure:

[0064] (1) Size and integration: The size of the tilted fiber Bragg grating structure is 125 μm, which is easier to combine with the ordinary single-mode fiber system and is suitable for long-distance transmission.

[0065] (2) Stability: The SPR detection system composed of the tilted fiber Bragg grating can maintain high-precision stability for a long time, which benefits from its good stable structure and materials. At the same time, it is not easily affected by the external environment (such as temperature, humidity, vibration, etc.) and is more stable and robust.

[0066] (3) Maintenance convenience: The present application performs automatic sampling and automatic analysis. Moreover, since the tilted fiber Bragg grating constitutes the detection system, fewer components are required, the structure is simple, and less maintenance is needed.

[0067] (4) Detection sensitivity: The tilted fiber Bragg grating has a higher refractive index sensitivity compared to the traditional SPR detection structure, which gives the present application an obvious advantage in the field of trace pollutant detection.

[0068] (5) Resistance to environmental interference: The tilted fiber Bragg grating SPR detection system can resist the influence of electromagnetic, corrosion, high temperature, and complex saline-alkali water environments.

[0069] In the embodiment of the present application, the principle of the tilted fiber Bragg grating is as follows:

[0070] The TFBG not only reflects the light in the core but also reflects part of the light to the cladding. The light propagating forward and backward reflected in the cladding undergoes coupling to form a specific coupling wavelength. The coupling of different orders of cladding modes and core modes will generate different resonance peaks, and the corresponding phase matching condition is:

[0071] λ cl,i =(n co +n cl,i )Λ g / cosθ g

[0072] where n co is the refractive index of the core, n cl,i is the refractive index of the i-th energy level cladding mode, Λ g is the grating pitch, λ cl,i is the resonant wave of the cladding mode, and θ g is the tilt angle of the grating. Due to the reflection and coupling of light of each energy level wavelength, a series of cladding mode resonance peaks can be seen in the transmission spectrum of the grating in the direction of the Bragg wavelength and its short wavelength. As the period and tilt angle of the grating change, the distribution range and period of these cladding mode resonance peaks will also change. Generally speaking, a longer period and a larger tilt angle can improve the resolution of the TFBG sensor.

[0073] In the embodiment of the present application, the resonance principle of surface plasmon is as follows:

[0074] Surface plasmons (SPs) are a type of electromagnetic surface wave. The electrons in the metal are still in an oscillating state but are confined by the metal surface. The surface plasmon has the maximum field strength at the surface and an exponentially decaying field in the direction perpendicular to the interface. It can be excited by electrons as well as light waves. When excited, the free electrons interact with the incident photons of the same frequency, resulting in collective oscillations. Therefore, this interaction generates a transverse magnetic wave (TM) that propagates along the interface between the metal and the dielectric, which is the surface plasmon wave (SPW). The SPW is a longitudinal electric field triggered by the vertical oscillation of the electrons on the metal surface and can only be excited by transverse magnetic (TM) polarization. By solving the Maxwell equations, the plasmon wave can be expressed as:

[0075]

[0076] where ε m is the dielectric constant of the metal film, and ε d is the dielectric constant of the surrounding environment.

[0077] In step S201, after the sample to be detected is placed in the liquid storage tank with the tilted grating, the real-time spectral data collected by the spectrometer is obtained. The real-time spectral data includes the sample spectral data and the light source spectral data.

[0078] In the embodiment of the present application, the control module in the previous section can be directly called to complete the acquisition. It should be noted that the real-time spectrum of the sample for a single sampling is the superposition of the sample grating spectrum and the light source spectrum. To avoid the influence of the light source spectrum on data processing (the experimental light source is in the shape of a comb and is likely to affect the grating-shaped spectrum), it must be excluded during post-processing. Therefore, the real-time sampled sample spectrum and the separately sampled light source spectrum need to be input here.

[0079] In step S202, the grating spectral data is calculated based on the sample spectral data and the light source spectral data.

[0080] In the embodiment of the present application, by subtracting the light source spectrum from the sampled sample spectrum, the waveform influence of the spectrum can be removed.

[0081] In step S203, a spectral wave valley identification operation is performed on the grating spectral data to obtain the grating wave valley data.

[0082] In the embodiment of the present application, the wave valleys in the spectrum are identified to prepare for the subsequent SPR wavelength identification.

[0083] In step S204, a spectral SPR response identification operation is performed on the grating wave valley data to obtain the SPR wavelength data.

[0084] In the embodiments of the present application, the SPR response in the recognition spectrum is recognized, that is, the inwardly concave part in the trough envelope is recognized. The principle is that the sampled spectrum is regarded as the spectrum after adding the SPR response to the original grating spectrum, and the original grating spectrum can be Gaussian-fitted to the envelope. The recognition scheme follows the idea of Gaussian fitting - performing Gaussian fitting on the trough sequence of the input spectrum, and at the same time setting a sliding window, and the trough points in the sliding window do not participate in the Gaussian fitting. During the recognition process, the sliding window traverses the entire trough sequence, records the parameters of the sliding window with the best fitting effect during the process, and these troughs are the parts affected by SPR. Taking the average value of the wavelengths of these troughs is the SPR wavelength.

[0085] In step S205, a drawing operation is performed according to the SPR wavelength data to obtain the real-time microplastic detection result.

[0086] In the embodiments of the present application, the spectrum with the best fitting effect in the "spectrum SPR response recognition" is drawn and stored in a file.

[0087] In step S206, the real-time microplastic detection result is output.

[0088] In some alternative implementation manners of the embodiments of the present application, the intermediate data and images in the above steps can be saved to a specified path to facilitate subsequent data review.

[0089] In the embodiments of the present application, a real-time microplastic detection method is provided, including: after the sample to be detected is placed in the liquid storage tank provided with an inclined grating, obtaining the real-time spectrum data collected by the spectrometer, where the real-time spectrum data includes the sample spectrum data and the light source spectrum data; calculating the grating spectrum data according to the sample spectrum data and the light source spectrum data; performing a spectrum trough recognition operation on the grating spectrum data to obtain the grating trough data; performing a spectrum SPR response recognition operation on the grating trough data to obtain the SPR wavelength data; performing a drawing operation according to the SPR wavelength data to obtain the real-time microplastic detection result; outputting the real-time microplastic detection result. Compared with the prior art, the present application provides a faster and more efficient detection system in the inclined fiber grating - surface plasmon resonance detection system, bringing an innovative solution to fields such as biosensing, chemical analysis, and environmental monitoring.

[0090] In some alternative implementation manners of the embodiments of the present application, after the step of calculating the grating spectrum data according to the sample spectrum data and the light source spectrum data, and before the step of performing a spectrum trough recognition operation on the grating spectrum data to obtain the grating trough data, the following steps are further included:

[0091] Performing smoothing processing on the grating spectrum data.

[0092] In the embodiments of the present application, median filtering is used for smoothing processing. The principle is to replace a certain value in the data with the median value in its neighborhood. If there are no other values on its left and right, it is filled with 0. For example, the method scipy.signal.medfilt(volume, kernel_size = None) has two parameters. The first parameter volume is the original data, and the second parameter kernel_size is the neighborhood size. For example, for one-dimensional data [7, 3, 9] with a neighborhood of 3 for median filtering, the neighborhood of the first value 7 is [0, 7, 3], and the median is 3; the neighborhood of the second value 3 is [7, 3, 9], and the median is 7; the neighborhood of the third value 9 is [3, 9, 0], and the median is 3; therefore, the data after median filtering is [3, 7, 3].

[0093] In practical applications, refer to Figure 4 the effect diagrams before and after median filtering shown in the figure. Among them, figure (a) is before filtering, and figure (b) is after filtering. By comparison, it can be seen that the filtering effect of a large reduction in the original spectral spikes is achieved.

[0094] In the embodiments of the present application, the spectrograms sampled in real time contain a lot of noise. In this study, median filtering is used to suppress the noise of the grating spectrogram. The principle is to replace the value of a certain point with the median value of the neighborhood of this point to eliminate the noise in the original data (image or time series data).

[0095] In some alternative implementation manners of the embodiments of the present application, the step of performing spectral valley identification operation on the grating spectrogram data to obtain grating valley data specifically includes the following steps:

[0096] Identify the valleys of the grating spectrogram data according to the signal.find_peaks() method to obtain grating valley data.

[0097] In the embodiments of the present application, signal.find_peaks() method is used for valley identification. If you want to use it to find valleys, you only need to reverse the positive and negative of each input data, that is, multiply by -1, then the obtained peaks are the found valleys. The principle of signal.find_peaks() for peak finding is to identify local maximum points. If a value is larger than both its left and right sides, it is a local maximum - a peak. In the actual identification process, the distance between peaks can be set through the distance parameter to avoid detecting peaks that are very close to each other.

[0098] In practical applications, refer to Figure 5 the effect diagrams before and after peak finding shown in the figure. By performing peak finding processing on the experimental data, it can be seen that the valley identification effect is obvious in the cladding resonance peak region.

[0099] In some alternative implementation manners of the embodiments of the present application, the step of performing a spectral SPR response recognition operation on the grating valley data to obtain SPR wavelength data specifically includes the following steps:

[0100] Obtain a preset sliding window, and perform a Gaussian fitting operation on the grating valley data according to the sliding window to obtain valleys affected by SPR;

[0101] Calculate the wavelength mean value of the valleys affected by SPR to obtain SPR wavelength data.

[0102] In the embodiments of the present application, a sliding window needs to be set when identifying the SPR wavelength. The valley points within the sliding window do not participate in the Gaussian fitting. The sliding window traverses all valley sequences, and the sliding window value with the best Gaussian fitting effect is used to calculate the SPR wavelength. The so-called Gaussian fitting is to use a Gaussian function as a template to find the Gaussian function closest to the input data, and this function is the fitted function. This fitting method can be scipy.optimize.curve_fit(), which can receive a custom function template (here it is a first-order Gaussian function) and perform a least squares fitting on it, so that the function is expressed as:

[0103]

[0104] Among them, the smallest set of parameters p is the best fitting state.

[0105] In practical applications, referring to Figure 6 the Gaussian fitting effect diagram shown, where the valleys (gray points) in the window do not participate in the fitting, and it can be seen that the Gaussian fitting effect is good after removing the points in the window.

[0106] In practical applications, the traditional TFBG-SPR detection rarely mentions its effect in terms of real-time performance. According to empirical analysis, they generally complete the detection by means of manual spectrum acquisition and manual data analysis. On the premise that the TFBG-SPR sensor has been prepared and the sample to be measured has been sampled, the detection time is analyzed as follows Figure 7 shown.

[0107] In the embodiments of the present application, the "spectrometer control acquisition module" replaces the "equipment adjustment" and "response" parts of the traditional TFBG-SPR detection, which is improved from the original 2.7 min to 1.5 min, only 55.6% (1.5 / 2.7) of the original, and the detection speed is 1.8 times that of the original (2.7 / 1.5). The "data real-time processing module" replaces the "single-sample processing part", which is improved from the original 6 min to 0.05 min, only 0.8% (0.05 / 6) of the original, and the detection speed is 120 times that of the original (6 / 0.05).

[0108] The engineering replacement of the "spectrometer control and acquisition module" and the "real-time data processing module" not only significantly improves the direct detection speed but also provides an engineering basis for more practical detection scenarios. For example, in the scenario proposed in 1.3.3, when monitoring a certain indicator during the sewage treatment process, when the real-time detection value exceeds or is lower than a certain boundary, some intervention measures need to be added to keep the indicator within an acceptable range. To handle such a practical scenario, only by converting the SPR wavelength into the indicator to be measured on the current basis can automatic indicator monitoring be completed; by adding an automatic intervention measure (such as automatically adding a certain chemical agent), automatic monitoring of the indicator can be achieved.

[0109] In summary, this application realizes the real-time and rapid detection of microplastics by the tilted fiber Bragg grating SPR system.

[0110] In practical applications, this application selects polystyrene suspension as a representative of suspensions to verify the detection function of the system for suspensions. This is mainly because polystyrene is widely used and representative. Polystyrene has a wide range of applications in many fields such as industry, materials science, and biomedicine. In the field of materials, polystyrene is a commonly used plastic raw material, and its particle suspension can simulate the state of raw materials during the plastic processing process. In the field of biomedicine, polystyrene microspheres are often used in research such as cell labeling and drug carriers, and the detection of their suspensions is of great significance for quality control and performance evaluation in these applications.

[0111] In the detection of polystyrene solutions with different particle sizes, the corresponding relationship between the SPR wavelength of the suspension and the particle size of polystyrene is as Figure 8 shown. Among them, for polystyrene microspheres with sizes of 50 nm and 100 nm, the SPR wavelength decreases as the microspheres increase. This is because at the same concentration, the larger the diameter of the microspheres, the fewer the number of microspheres, the smaller the refractive index contribution of the microspheres to the liquid, the smaller the refractive index of the liquid, and the smaller the SPR wavelength.

[0112] In the detection of the concentration of polystyrene suspension, through the experiments in the previous section, it can be known that the detection system has better sensitivity in polystyrene suspension with a particle size of 50 nm. Therefore, in this experiment, polystyrene suspension with a particle size of 50 nm is selected to analyze the relationship between its SPR wavelength and its concentration change. The fitting of the SPR wavelength of the liquid with its concentration change is as Figure 9 shown, where the fitting curve is, the fitting is 0.8866, and the concentration detection limit is 5 mg / mL. It can be found that although the liquid is a suspension and its properties are relatively unstable, it can still be clearly seen that the SPR wavelength is positively correlated with the concentration c of the polystyrene suspension.

[0113] Embodiments of this application can acquire and process relevant data based on artificial intelligence technology. Among them, Artificial Intelligence (AI) uses digital computers or machines controlled by digital computers to simulate, extend, and expand human intelligence, and is a theory, method, technology, and application system that can perceive the environment, acquire knowledge, and use knowledge to obtain the best results.

[0114] Artificial intelligence basic technologies generally include technologies such as sensors, dedicated artificial intelligence chips, cloud computing, distributed storage, big data processing technology, operation / interaction systems, and mechatronics. Artificial intelligence software technologies mainly include several major directions such as computer vision technology, robotics, biometric technology, speech processing technology, natural language processing technology, and machine learning / deep learning.

[0115] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through computer-readable instructions. These computer-readable instructions can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above methods. Among them, the aforementioned storage medium can be a non-volatile storage medium such as a magnetic disk, optical disk, Read-Only Memory (ROM), or a Random Access Memory (RAM), etc.

[0116] It should be understood that although the steps in the flowchart of the accompanying drawings are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed alternately or alternately with at least a part of other steps or sub-steps or stages of other steps.

[0117] Further reference Figure 10 to Figure 2 , as an implementation of the method shown above Figure 2 , this application provides an embodiment of a microplastic real-time detection device. This device is applied to an inclined fiber Bragg grating SPR detection system. Among them, the inclined fiber Bragg grating SPR detection system includes: a broadband light source, an optical fiber polarizer, a polarization controller, a liquid storage tank provided with an inclined grating, and a spectrometer. This device embodiment corresponds to

[0118] As Figure 10 shown, the real-time microplastic detection device 200 of the embodiment of the present application includes:

[0119] A real-time spectrum acquisition module 210, configured to acquire real-time spectrum data collected by a spectrometer after a sample to be detected is placed in a liquid storage tank provided with a tilted grating, wherein the real-time spectrum data includes sample spectrum data and light source spectrum data;

[0120] A grating spectrum calculation module 220, configured to calculate grating spectrum data according to the sample spectrum data and the light source spectrum data;

[0121] A spectrum trough identification module 230, configured to perform a spectrum trough identification operation on the grating spectrum data to obtain grating trough data;

[0122] A spectrum SPR response identification module 240, configured to perform a spectrum SPR response identification operation on the grating trough data to obtain SPR wavelength data;

[0123] A plotting module 250, configured to perform a plotting operation according to the SPR wavelength data to obtain a real-time microplastic detection result;

[0124] An output module 260, configured to output the real-time microplastic detection result.

[0125] In the embodiment of the present application, a real-time microplastic detection device 200 is provided. The device 200 is applied to a tilted fiber grating SPR detection system. The tilted fiber grating SPR detection system includes: a broadband light source, an optical fiber polarizer, a polarization controller, a liquid storage tank provided with a tilted grating, and a spectrometer. The device 200 includes: a real-time spectrum acquisition module 210, configured to acquire real-time spectrum data collected by a spectrometer after a sample to be detected is placed in a liquid storage tank provided with a tilted grating, wherein the real-time spectrum data includes sample spectrum data and light source spectrum data; a grating spectrum calculation module 220, configured to calculate grating spectrum data according to the sample spectrum data and the light source spectrum data; a spectrum trough identification module 230, configured to perform a spectrum trough identification operation on the grating spectrum data to obtain grating trough data; a spectrum SPR response identification module 240, configured to perform a spectrum SPR response identification operation on the grating trough data to obtain SPR wavelength data; a plotting module 250, configured to perform a plotting operation according to the SPR wavelength data to obtain a real-time microplastic detection result; an output module 260, configured to output the real-time microplastic detection result. Compared with the prior art, the present application provides a faster and more efficient detection system in a tilted fiber grating - surface plasmon resonance detection system, bringing innovative solutions to fields such as biosensing, chemical analysis, and environmental monitoring.

[0126] In some alternative implementation manners of the embodiments of the present application, the above-mentioned microplastic real-time detection device 200 further includes: a smoothing processing module, where:

[0127] The smoothing processing module is used to perform smoothing processing on the grating spectral data.

[0128] In some alternative implementation manners of the embodiments of the present application, the above-mentioned spectral valley identification module includes: a spectral valley identification sub-module, where:

[0129] The spectral valley identification sub-module is used to identify the valleys of the grating spectral data according to the signal.find_peaks() method to obtain the grating valley data.

[0130] In some alternative implementation manners of the embodiments of the present application, the above-mentioned spectral SPR response identification module includes: a Gaussian fitting sub-module and a wavelength mean calculation sub-module, where:

[0131] The Gaussian fitting sub-module is used to obtain a preset sliding window and perform Gaussian fitting operation on the grating valley data according to the sliding window to obtain the valleys affected by SPR;

[0132] The wavelength mean calculation sub-module is used to calculate the wavelength mean of the valleys affected by SPR to obtain the SPR wavelength data.

[0133] In some alternative implementation manners of the embodiments of the present application, the light source wavelength range of the above-mentioned broadband light source is 1370nm to 1700nm, and the power is 50μW.

[0134] In some alternative implementation manners of the embodiments of the present application, the tilt angle parameter of the above-mentioned tilted grating is 10°, the Bragg wavelength is 1550nm, and the spectral range of the cladding resonance peak of the tilted grating is 1480nm to 1550nm.

[0135] In some alternative implementation manners of the embodiments of the present application, the spectral range of the above-mentioned fiber optic polarizer is 1430nm to 1530nm.

[0136] To solve the above technical problems, the embodiments of the present application also provide a computer device. For details, please refer to Figure 11 , Figure 11 which is the basic structural block diagram of the computer device in the embodiments of the present application.

[0137] The computer device 300 includes a memory 310, a processor 320, and a network interface 330 that are communicatively connected to each other via a system bus. It should be noted that only the computer device 300 with components 310 - 330 is shown in the figure, but it should be understood that it is not required to implement all the shown components, and more or fewer components can be implemented alternatively. Among them, those skilled in the art of this technology can understand that the computer device here is a device that can automatically perform numerical calculations and / or information processing according to pre-set or stored instructions, and its hardware includes but is not limited to microprocessors, application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), embedded devices, etc.

[0138] The computer device can be a computing device such as a desktop computer, a notebook, a palm computer, and a cloud server. The computer device can perform human-computer interaction with the user through a keyboard, a mouse, a remote control, a touchpad, a voice control device, etc.

[0139] The memory 310 includes at least one type of readable storage medium, and the readable storage medium includes flash memory, hard disks, multimedia cards, card-type memories (such as SD or DX memories, etc.), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memories, magnetic disks, optical discs, etc. In some embodiments, the memory 310 can be an internal storage unit of the computer device 300, such as the hard disk or memory of the computer device 300. In other embodiments, the memory 310 can also be an external storage device of the computer device 300, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the computer device 300. Of course, the memory 310 can also include both the internal storage unit and the external storage device of the computer device 300. In the embodiments of the present application, the memory 310 is generally used to store the operating system and various application software installed on the computer device 300, such as computer-readable instructions for the real-time detection method of microplastics. In addition, the memory 310 can also be used to temporarily store various data that have been output or will be output.

[0140] In some embodiments, the processor 320 may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chips. The processor 320 is generally used to control the overall operation of the computer device 300. In the embodiments of the present application, the processor 320 is used to run the computer-readable instructions stored in the memory 310 or process data, such as running the computer-readable instructions of the microplastic real-time detection method.

[0141] The network interface 330 may include a wireless network interface or a wired network interface, which is generally used to establish a communication connection between the computer device 300 and other electronic devices.

[0142] The computer device provided by the present application provides a faster and more efficient detection system in the tilted fiber Bragg grating - surface plasmon resonance detection system, bringing innovative solutions to fields such as biosensing, chemical analysis, and environmental monitoring.

[0143] The present application also provides another implementation manner, that is, to provide a computer-readable storage medium storing computer-readable instructions, which can be executed by at least one processor, so that the at least one processor executes the steps of the microplastic real-time detection method as described above.

[0144] The computer-readable storage medium provided by the present application provides a faster and more efficient detection system in the tilted fiber Bragg grating - surface plasmon resonance detection system, bringing innovative solutions to fields such as biosensing, chemical analysis, and environmental monitoring.

[0145] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-described embodiment methods can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes several instructions for causing a terminal device (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in the various embodiments of the present application.

[0146] Obviously, the embodiments described above are only a part of the embodiments of the present application, rather than all of the embodiments. The preferred embodiments of the present application are given in the accompanying drawings, but they do not limit the patent scope of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosed content of the present application more thorough and comprehensive. Although the present application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing specific embodiments, or perform equivalent replacements on some of the technical features. Any equivalent structure made by using the content of the specification and drawings of the present application, directly or indirectly applied in other related technical fields, is equally within the scope of patent protection of the present application.

Claims

1. A real-time detection method for microplastics, characterized in that, The method is applied to an inclined fiber Bragg grating SPR detection system, wherein the inclined fiber Bragg grating SPR detection system includes: a broadband light source, an optical fiber polarizer, a polarization controller, a liquid storage tank provided with an inclined grating, and a spectrometer. The method includes the following steps: After the sample to be detected is placed in the liquid storage tank provided with the inclined grating, obtain the real-time spectral data collected by the spectrometer, wherein the real-time spectral data includes sample spectral data and light source spectral data; Calculate the grating spectral data according to the sample spectral data and the light source spectral data; Perform a spectral valley identification operation on the grating spectral data to obtain grating valley data; Perform a spectral SPR response identification operation on the grating valley data to obtain SPR wavelength data; Perform a plotting operation according to the SPR wavelength data to obtain a real-time microplastic detection result; Output the real-time microplastic detection result.

2. The real-time microplastic detection method according to claim 1, wherein After the step of calculating the grating spectral data according to the sample spectral data and the light source spectral data, and before the step of performing a spectral valley identification operation on the grating spectral data to obtain grating valley data, the following steps are further included: Perform smoothing processing on the grating spectral data.

3. The real-time detection method of microplastics according to claim 1, characterized in that The step of performing a spectral valley identification operation on the grating spectral data to obtain grating valley data specifically includes the following steps: Identify the valleys of the grating spectral data according to the signal.find_peaks() method to obtain the grating valley data.

4. The real-time detection method of microplastics according to claim 1, wherein The step of performing a spectral SPR response identification operation on the grating valley data to obtain SPR wavelength data specifically includes the following steps: Obtain a preset sliding window, and perform Gaussian fitting operation on the grating valley data according to the sliding window to obtain valleys affected by SPR; Calculate the wavelength mean of the valleys affected by SPR to obtain the SPR wavelength data.

5. The real-time microplastic detection method according to claim 1, wherein The light source wavelength range of the broadband light source is 1370nm - 1700nm, and the power is 50μW.

6. The real-time microplastic detection method according to claim 1, characterized in that, The inclination parameter of the inclined grating is 10°, the Bragg wavelength is 1550nm, and the spectral range of the cladding resonance peak of the inclined grating is 1480nm - 1550nm.

7. The real-time detection method for microplastics according to claim 1, wherein The spectral range of the optical fiber polarizer is 1430nm - 1530nm.

8. A microplastic real-time detection device, which is applied to an inclined fiber Bragg grating SPR detection system, wherein, The inclined fiber Bragg grating SPR detection system includes: a broadband light source, an optical fiber polarizer, a polarization controller, a liquid storage tank provided with an inclined grating, and a spectrometer, and is characterized by including: A real-time spectrum acquisition module, configured to obtain the real-time spectral data collected by the spectrometer after the sample to be detected is placed in the liquid storage tank provided with the inclined grating, wherein the real-time spectral data includes sample spectral data and light source spectral data; A grating spectrum calculation module, configured to calculate the grating spectral data according to the sample spectral data and the light source spectral data; A spectral valley identification module, configured to perform a spectral valley identification operation on the grating spectral data to obtain grating valley data; A spectral SPR response recognition module, which is used to perform spectral SPR response recognition operations on the grating trough data to obtain SPR wavelength data; A plotting module, which is used to perform plotting operations based on the SPR wavelength data to obtain real-time microplastic detection results; An output module, which is used to output the real-time microplastic detection results.

9. A computer device, comprising a memory and a processor, characterized in that, Computer-readable instructions are stored in the memory, and when the processor executes the computer-readable instructions, the steps of the real-time microplastic detection method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that, Computer-readable instructions are stored on the computer-readable storage medium, and when the computer-readable instructions are executed by the processor, the steps of the real-time microplastic detection method according to any one of claims 1 to 7 are implemented.

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