Method and system for measuring substance concentration based on Raman spectrum

Abstract

The invention discloses a substance concentration measuring method and a substance concentration measuring system based on Raman spectrum, which are mainly used in the technical fields of biomedical engineering and analytical chemistry. The method comprises the following steps: dividing a solution sample to be detected into samples in a plurality of collection areas, wherein the sample in each collection area comprises a plurality of sample points; according to a preset array rule, performing laser irradiation on the sample in each acquisition area to obtain an optical signal array corresponding to a plurality of array rules; when laser irradiation is carried out on the acquisition area, optical signals corresponding to each sample point in the acquisition area are acquired, and an optical signal array corresponding to the acquisition area is generated; generating a target signal set based on the optical signal array corresponding to each acquisition area; and determining the concentration of the target substance in the solution sample to be detected based on the mapping relationship between the target signal in the target signal set and the target substance. According to the invention, the accuracy of measuring low-concentration substances can be improved, and meanwhile, the measuring speed is increased.

Description

Technical Field

[0001] The present invention relates to the technical fields of biomedical engineering and analytical chemistry, and particularly relates to a method and system for measuring the concentration of a substance based on Raman spectroscopy. Background Art

[0002] In the related art, a method for measuring the concentration of a substance based on digital colloidal enhanced Raman spectroscopy predicts the specific concentration of a target molecule according to the proportion of positive signals in the total number of signals, so as to quantitatively measure the concentration of a low-concentration substance. Although this method for measuring the concentration of a substance can measure the concentration of a low-concentration substance, since this method for measuring the concentration of a substance needs to obtain a sufficient number of spectral samples to determine the concentration of the substance, and the efficiency of obtaining spectral samples limits the concentration measurement efficiency. Therefore, when using this method to measure the concentration of a substance, a large amount of time cost and labor cost are often consumed due to the low concentration measurement efficiency. Summary of the Invention

[0003] The present invention provides a method and system for measuring the concentration of a substance based on Raman spectroscopy, which can improve the accuracy of measuring a low-concentration substance and simultaneously increase the measurement speed, thereby facilitating the reduction of time cost and labor cost.

[0004] The present invention provides a method for measuring the concentration of a substance based on Raman spectroscopy, and the method includes: Dividing a sample of a solution to be measured into samples in a plurality of acquisition regions, and each sample in the acquisition region includes a plurality of sample points; According to a preset array rule, laser irradiating the samples in each acquisition region to obtain a plurality of optical signal arrays corresponding to the array rule; When laser irradiating the acquisition region, collecting the optical signals corresponding to each sample point in the acquisition region and generating an optical signal array corresponding to the acquisition region; Generating a target signal set based on the optical signal array corresponding to each acquisition region; Determining the concentration of the target substance in the sample of the solution to be measured based on the mapping relationship between the target signal and the target substance in the target signal set.

[0005] Optionally, generating a target signal set based on the optical signal array corresponding to each acquisition region includes: Identifying the optical signal array corresponding to each acquisition region by using a preset threshold according to the target substance; Judging whether each optical signal in the optical signal array is an optical signal corresponding to the target substance. If so, generating a first digital signal; if not, generating a second digital signal; Generate the target signal set based on the multiple first digital signals and the multiple second digital signals.

[0006] Optionally, determining the concentration of the target substance in the sample solution to be measured based on the mapping relationship between the target signal and the target substance in the target signal set includes: Determine the proportion value of the first digital signal in the target signal set; Generate the linear relationship between the proportion value and the molecular concentration in the logarithmic coordinate system; Based on the linear relationship between the proportion value and the molecular concentration in the logarithmic coordinate system, use a preset prediction model to predict and determine the concentration of the target substance in the sample solution to be measured.

[0007] Optionally, the method includes: Set the acquisition area; The step of setting the acquisition area includes: Generate a laser beam based on a preset intensity and a preset focal length; Determine the coordinate value range of the focus of the laser beam according to the position of the target sample point; Determine the acquisition area based on the coordinate value range; When performing a laser irradiation operation on each sample point in the acquisition area using the laser beam, obtain a feedback signal and adjust the control parameters of the laser irradiation operation according to the feedback signal. The control parameters include a step value and an exposure time. Among them, adjust the step value according to the distance between each sample point in the acquisition area, or adjust the exposure time according to the intensity value of the feedback signal.

[0008] The present invention also provides a substance concentration measurement system based on Raman spectroscopy. The system includes a sample measurement unit and a signal processing unit; The sample measurement unit is used to divide the sample solution to be measured into samples in multiple acquisition areas. Each sample in the acquisition area includes multiple sample points; according to a preset array rule, perform laser irradiation on the samples in each acquisition area to obtain multiple optical signal arrays corresponding to the array rules; when performing laser irradiation on the acquisition area, collect the optical signals corresponding to each sample point in the acquisition area and generate the optical signal array corresponding to the acquisition area; The signal processing unit is used to generate a target signal set based on the optical signal array corresponding to each acquisition area; determine the concentration of the target substance in the sample solution to be measured based on the mapping relationship between the target signal and the target substance in the target signal set.

[0009] Optionally, the signal processing unit is further used for: Identify the optical signal array corresponding to each of the acquisition regions using a preset threshold according to the target substance; Determine whether each optical signal in the optical signal array is the optical signal corresponding to the target substance. If so, generate a first digital signal; if not, generate a second digital signal; Generate the target signal set based on the multiple first digital signals and the multiple second digital signals.

[0010] Optionally, the signal processing unit is further configured to: Determine the proportion value of the first digital signal in the target signal set; Generate a linear relationship between the proportion value and the molecular concentration in a logarithmic coordinate system; Based on the linear relationship between the proportion value and the molecular concentration in the logarithmic coordinate system, use a preset prediction model to make a prediction and determine the concentration of the target substance in the sample solution to be measured.

[0011] Optionally, the sample measurement unit is further configured to: Generate a laser beam based on a preset intensity and a preset focal length; Determine the coordinate value range of the focus of the laser beam according to the position of the target sample point; Determine the acquisition region based on the coordinate value range; When performing a laser irradiation operation on each sample point in the acquisition region using the laser beam, obtain a feedback signal and adjust the control parameters of the laser irradiation operation according to the feedback signal. The control parameters include a step value and an exposure time. Among them, the step value is adjusted according to the distance between each sample point in the acquisition region, or the exposure time is adjusted according to the intensity value of the feedback signal.

[0012] Optionally, the sample measurement unit includes a phase modulator module; The phase modulator module is configured to split the laser beam to obtain an array of lasers for laser irradiation of the sample points in the acquisition region.

[0013] Optionally, the signal processing unit includes a signal conversion module, and the signal conversion module includes a spectrometer and a signal conversion device; The spectrometer is configured to collect the optical signals excited by the laser irradiation, split the collected optical signals into optical signals of multiple wavelengths and output them to the signal conversion device; The signal conversion device is configured to convert the optical signal of each wavelength into an electrical signal.

[0014] The present invention has at least the following beneficial effects: The technical solution of this application uses array light with a preset array rule to irradiate multiple sample points with laser to collect the optical signals corresponding to each sample point in the acquisition area, and realizes the acquisition of Raman spectrum information of multiple sample points simultaneously in the acquisition area by obtaining the optical signal array corresponding to each acquisition area, improving the sampling speed, so as to quickly sample all sample points on the sample solution to be measured. By quickly collecting the target signals of a large number of sample points to form a target signal set, and finally determining the concentration of the target substance in the sample solution to be measured based on the target signal set, the measurement speed is greatly improved. Compared with the existing technical solutions, since more target signals are collected more efficiently, more target signals are used for concentration measurement when measuring the concentration of the sample solution to be measured, which is beneficial to improving the accuracy of measuring low-concentration substances. In addition, the technical solution of this application saves more manual operation steps, which is beneficial to reducing the time cost and labor cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings are used to provide a further understanding of the technical solutions of the present invention, and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation to the technical solutions of the present invention.

[0016] Figure 1 is a flowchart of the steps of a method for measuring the concentration of a substance based on Raman spectroscopy; Figure 2 is a flowchart of the steps of step S104 in a method for measuring the concentration of a substance based on Raman spectroscopy; Figure 3 is a flowchart of the steps of step S105 in a method for measuring the concentration of a substance based on Raman spectroscopy; Figure 4 is a flowchart of the steps of setting an acquisition area in a method for measuring the concentration of a substance based on Raman spectroscopy; Figure 5 is a first structural schematic diagram of a system for measuring the concentration of a substance based on Raman spectroscopy; Figure 6 is a second structural schematic diagram of a system for measuring the concentration of a substance based on Raman spectroscopy; Figure 7 is a schematic diagram of a sample solution to be measured in a system for measuring the concentration of a substance based on Raman spectroscopy; Among them, 510, sample measurement unit; 511, filter; 512, phase modulator module; 513, laser emitter; 514, lens; 515, objective lens; 516, sample solution to be measured; 517, displacement stage; 520, signal processing unit; 521, signal conversion device; 522, spectrometer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0018] It should be noted that Raman spectroscopy technology obtains the fingerprint information of substances, such as the vibration or rotation of the molecular chemical structure itself, by measuring the anti-Stokes lines in the light scattering effect, so as to realize the detection of substances. However, the signal intensity of traditional Raman spectroscopy technology is usually weak and vulnerable to fluorescence interference, so there are challenges in detecting low-concentration substances. Surface-enhanced Raman spectroscopy (SERS) technology uses the local plasmon resonance electromagnetic field enhancement effect on the surface of metal nanoparticles to enhance the Raman scattering signal, achieving the purpose of enhancing the Raman spectroscopy signal. Compared with traditional Raman spectroscopy technology, fluorescence spectroscopy, and infrared spectroscopy technology, SERS significantly improves the signal-to-noise ratio and reduces background interference by enhancing the signal intensity. Due to its high sensitivity, SERS can resolve subtle changes in the molecular structure and has good resolution ability for subtle differences between molecules. In addition, the preparation process of SERS is simple and the cost is low. Based on the above advantages, SERS technology has been proven to have great application potential in quantitative detection in the fields of cancer cell detection, disease diagnosis, agricultural drug concentration detection, food safety, environmental science, etc.

[0019] However, the repeatability of quantitatively detecting the concentration of the target substance by SERS technology is poor. The specific reasons are that the hot spots for SERS signal enhancement are often uneven, the adsorption positions of molecules on the surface of nanoparticles are uncertain, and the local electromagnetic field enhancement effect encoded by metal nanoparticles is often highly locally variable. To address this challenge of poor repeatability, efforts have been made to fabricate high-quality solid substrates, such as further optimizing the shape and size of nanoparticles, attempting to fabricate multi-layer and composite nanoparticle structures, and modifying molecules with specific functions on the surface of metal nanoparticles. But so far, these efforts have only achieved limited effects on some selected target molecules.

[0020] To solve the problem of poor repeatability in quantitatively detecting the concentration of target substances in SERS technology, Alexandre G. Brolo et al. first introduced a digital quantitative detection method in solid-phase SERS detection. By measuring Raman spectra multiple times at different positions on a solid substrate, the Raman signals measured each time are digitized into "0" or "1" digital signals, i.e., negative signals or positive signals, according to their signal strengths. And the specific concentration of the target molecule is predicted by the proportion of positive signals in the total number of signals. However, this method is still limited by problems such as poor repeatability in the manufacturing process of solid-phase SERS substrates.

[0021] The technology of digital colloidal enhanced Raman spectroscopy (dCERC) uses a quartz capillary filled with a suspension of metal colloidal nanoparticles as the sample container, and a scanning probe system (numerical aperture 0.3, 10× objective lens, excitation wavelength 638 nm) is used to obtain Raman spectra. This method also introduces a digital measurement method to predict the specific concentration of the target molecule by the proportion of positive signals in the total number of signals, and it is verified that this method follows a Poisson distribution statistically and can achieve quantitative repeated measurement of low-concentration substances. And compared with solid substrates, due to the uniform distribution of single-molecule silver colloids in the entire suspension, it ensures that the probability of colloid-target interaction in the entire data acquisition chamber is almost the same. The manufacturing process of the substrate is also more mature. Although the technology of digital colloidal enhanced Raman spectroscopy (dCERC) can achieve repeated measurement of low-concentration substances, it is necessary to perform point-by-point multiple scans along the longitudinal axis of the quartz capillary to obtain enough spectral samples to estimate the proportion of positive signals in the total number of signals, and then obtain the concentration of the substance. The measurement accuracy of its concentration is also highly positively correlated with the number of measured samples. Therefore, the method for measuring the concentration of substances based on digital colloidal enhanced Raman spectroscopy predicts the specific concentration of the target molecule according to the proportion of positive signals in the total number of signals, so as to achieve quantitative measurement of the concentration of low-concentration substances. Although this method for measuring the concentration of substances can measure the concentration of low-concentration substances, since this method for measuring the concentration of substances needs to obtain enough spectral samples to determine the concentration of the substance, and the efficiency of obtaining spectral samples limits the concentration measurement efficiency. Therefore, when using this method to measure the concentration of substances, it often consumes a large amount of time cost and labor cost due to low concentration measurement efficiency. Due to the low concentration measurement efficiency of the method for measuring the concentration of substances applying Raman spectroscopy technology, the application of this technology in medical and other fields is very limited.

[0022] It can be seen that the existing technical solutions have the above-mentioned defects. The present invention aims to provide a method and system for measuring the concentration of substances based on Raman spectroscopy, which can improve the accuracy of measuring low-concentration substances and at the same time increase the measurement speed, thus helping to reduce time cost and labor cost.

[0023] To achieve the above object, the technical solution of the present application uses array light with a preset array rule to perform laser irradiation on multiple sample points to collect the optical signals corresponding to each sample point in the acquisition area, and realizes the acquisition of Raman spectrum information of multiple sample points simultaneously in the acquisition area by obtaining the optical signal array corresponding to each acquisition area, improving the sampling speed, so as to quickly sample all sample points on the sample solution to be measured. By quickly collecting the target signals of a large number of sample points to form a target signal set, and finally determining the concentration of the target substance in the sample solution to be measured based on the target signal set, the measurement speed is greatly improved. Compared with the prior art solution, since more target signals are collected more efficiently, more target signals are used for concentration measurement when measuring the concentration of the sample solution to be measured, which is beneficial to improving the accuracy of measuring low-concentration substances. In addition, the technical solution of the present application saves more manual operation steps, which is beneficial to reducing the time cost and labor cost. The technical solution of the present application is implemented through the following embodiments.

[0024] Please refer to Figure 1 , Figure 1 which is a flowchart of the steps of a method for measuring the concentration of a substance based on Raman spectroscopy.

[0025] In a first aspect, the present embodiment provides a method for measuring the concentration of a substance based on Raman spectroscopy, the method comprising: S101. Divide the sample solution to be measured into samples in multiple acquisition areas, and each sample in each acquisition area includes multiple sample points.

[0026] S102. According to the preset array rule, perform laser irradiation on the samples in each acquisition area to obtain optical signal arrays corresponding to multiple array rules.

[0027] S103. When performing laser irradiation on the acquisition area, collect the optical signals corresponding to each sample point in the acquisition area and generate an optical signal array corresponding to the acquisition area.

[0028] S104. Generate a target signal set based on the optical signal array corresponding to each acquisition area.

[0029] S105. Determine the concentration of the target substance in the sample solution to be measured based on the mapping relationship between the target signals in the target signal set and the target substance.

[0030] In step S101 of some embodiments, when preparing the sample solution to be measured, it is necessary to prepare a quartz capillary tube and input the sample solution to be measured into the quartz capillary tube to form the sample solution to be measured.

[0031] Optionally, the quartz capillary tube is a quartz capillary tube containing 10 ul of metal colloid suspension, and the inner diameter is 1 mm.

[0032] In some embodiments, the steps of fabricating a quartz capillary for a metal colloid suspension are as follows: A silver colloid suspension is generated by stirring. The liquid being stirred includes a certain amount of silver nitrate dissolved in pure water and a added reducing agent. At this point, the particle distribution of the suspension should be uniform and the suspension state should be stable. In terms of concentration, in order to ensure the required concentration, the suspension can be measured using an ultraviolet-visible spectrophotometer. After ensuring the concentration, the suspension is filtered using a filter membrane to remove possible large particles and impurities. In addition, in order to ensure that the suspension does not overflow or leak, the cleaned quartz capillary needs to be vertically fixed on a bracket. Then, the prepared metal colloid particle suspension is slowly injected into the capillary, and it is necessary to ensure that no bubbles are generated during the injection process and the distribution of the suspension in the capillary is uniform. Finally, sealing materials are also required to seal both ends of the capillary to ensure that the metal suspension inside the capillary does not evaporate or leak. When sealing, the stability of the suspension should also be maintained to ensure that no bubbles are generated.

[0033] In step S102 of some embodiments, the array rule can be the number of rows and columns of the optical signal array, or the row pitch and column pitch.

[0034] Please refer to Figure 2 , Figure 2 is a flowchart of step S104 in a method for measuring the concentration of a substance based on Raman spectroscopy.

[0035] In some embodiments, step S104 includes: S201. Identify the optical signal array corresponding to each acquisition area using a preset threshold according to the target substance.

[0036] S202. Determine whether each optical signal in the optical signal array is the optical signal corresponding to the target substance. If so, generate a first digital signal; if not, generate a second digital signal.

[0037] S203. Generate a target signal set based on multiple first digital signals and multiple second digital signals.

[0038] In this embodiment, through a preset threshold set manually, the optical signal array corresponding to each acquisition area is automatically identified to determine whether there is a Raman signal of the target substance in the optical signal array. The Raman signal obtained from each measurement is digitized into "0" or "1" according to its intensity, representing a negative or positive signal (the first digital signal is a positive signal, and the second digital signal is a negative signal).

[0039] Please refer to Figure 3 , Figure 3 is a flowchart of step S105 in a method for measuring the concentration of a substance based on Raman spectroscopy.

[0040] In some embodiments, step S105 includes: S301. Determine the proportion value of the first digital signal in the target signal set.

[0041] S302. Generate a linear relationship between the proportion value of the first digital signal in the target signal set and the molecular concentration in a logarithmic coordinate system.

[0042] S303. Based on the linear relationship between the proportion value of the first digital signal in the target signal set and the molecular concentration in a logarithmic coordinate system, use a preset prediction model to make a prediction and determine the concentration of the target substance in the sample solution to be measured.

[0043] In this embodiment, the first digital signal is a positive signal. Calculate the proportion of the positive signal in the total signals of the target signal set to obtain the proportion value, that is, count the number of spectra of the "1" digital signal and divide it by the total number of spectra of the total signals. Generate a linear relationship between the proportion value of the first digital signal in the target signal set and the molecular concentration in a logarithmic coordinate system, that is, establish a linear relationship between the positive spectral frequency index (RPV) and the molecular concentration in a logarithmic coordinate system. Use the linear relationship between the positive spectral frequency index (RPV) and the molecular concentration in a logarithmic coordinate system to predict and determine the concentration of the target substance in the sample solution to be measured.

[0044] Please refer to Figure 4 , Figure 4 which is a flowchart of the steps for setting an acquisition area in a method for measuring the concentration of a substance based on Raman spectroscopy.

[0045] In some embodiments, the method includes: setting an acquisition area.

[0046] Specifically, the steps for setting an acquisition area include: S401. Generate a laser beam based on a preset intensity and a preset focal length.

[0047] S402. According to the position of the target sample point, determine the coordinate value range of the focus of the laser beam.

[0048] S403. Based on the coordinate value range, determine the acquisition area.

[0049] S404. When performing a laser irradiation operation on each sample point in the acquisition area using the laser beam, obtain a feedback signal and adjust the control parameters of the laser irradiation operation according to the feedback signal. The control parameters include a step value and an exposure time. Among them, adjust the step value according to the distance between each sample point in the acquisition area, or adjust the exposure time according to the intensity value of the feedback signal.

[0050] It can be understood that before performing the laser irradiation operation using the Raman signal detection system, it is necessary to first start the Raman signal detection system and set the sampling parameters, such as the acquisition area, step size, exposure time, etc.

[0051] In some embodiments, first, each device is installed and calibrated to ensure that the hardware can work properly, and then the Raman signal detection system is initialized through the control software to ensure that the system can work properly. In this system, the adjustable parameters include laser intensity, measurement step size and area, and exposure time.

[0052] Laser intensity, the wavelength of the laser can usually select a laser of 532 nm, and ensure that the intensity is moderate and will not damage the measurement sample. After starting the laser light source, focus the laser on the surface of the measurement sample and adjust the focal length to ensure that the laser beam has been focused to the most suitable position.

[0053] Measurement step size and area, that is, in the measurement process, for the array light used, the distance between each single point. When the adopted distance is too small, it may not be possible to ensure that the measurement results conform to independent and identically distributed, so usually the range of the step size is set between 1 - 10 microns. And we need to set the Raman measurement area according to the needs of the experiment to ensure that all the Raman points to be measured in the capillary can be covered.

[0054] Exposure time, that is, the time used to collect a single Raman signal. A higher exposure time often has a higher signal intensity and signal-to-noise ratio. When measuring samples with a lower concentration and weaker signal, the exposure time can be appropriately extended to obtain sufficient signal intensity. Usually, the exposure time range can be set between 0.1 - 10 seconds.

[0055] When all the parameters are set, a pre-measurement can be performed first, that is, a test is first carried out on a small part of the measurement area, and according to the intensity and quality of the measured Raman signal, the parameters are continuously adjusted to ensure that the best signal quality and measurement efficiency can be obtained.

[0056] Please refer to Figure 5 , Figure 5 which is the first structural schematic diagram of a substance concentration measurement system based on Raman spectroscopy.

[0057] This embodiment provides a substance concentration measurement system based on Raman spectroscopy, and the system includes a sample measurement unit 510 and a signal processing unit 520.

[0058] A sample measurement unit 510 is configured to divide a sample of a solution to be measured into samples in a plurality of collection regions, and each sample in each collection region includes a plurality of sample points; according to a preset array rule, laser irradiate the samples in each collection region to obtain an optical signal array corresponding to a plurality of array rules; when laser irradiating a collection region, collect the optical signals corresponding to each sample point in the collection region and generate an optical signal array corresponding to the collection region.

[0059] A signal processing unit 520 is configured to generate a target signal set based on the optical signal array corresponding to each collection region; determine the concentration of the target substance in the sample of the solution to be measured based on the mapping relationship between the target signal and the target substance in the target signal set.

[0060] In some embodiments, the signal processing unit 520 is further configured to: Identify the optical signal array corresponding to each collection region by using a preset threshold according to the target substance; determine whether each optical signal in the optical signal array is an optical signal corresponding to the target substance, if so, generate a first digital signal, if not, generate a second digital signal; generate a target signal set based on the plurality of first digital signals and the plurality of second digital signals.

[0061] In some embodiments, the signal processing unit 520 is further configured to: Determine the proportion value of the first digital signal in the target signal set; generate a linear relationship between the proportion value and the molecular concentration in a logarithmic coordinate system; based on the linear relationship between the proportion value and the molecular concentration in the logarithmic coordinate system, use a preset prediction model to perform prediction and determine the concentration of the target substance in the sample of the solution to be measured.

[0062] In some embodiments, the sample measurement unit 510 is further configured to: Generate a laser beam based on a preset intensity and a preset focal length; determine the coordinate value range of the focus of the laser beam according to the position of the target sample point; determine the collection region based on the coordinate value range; when performing a laser irradiation operation on each sample point in the collection region by using the laser beam, obtain a feedback signal and adjust the control parameters of the laser irradiation operation according to the feedback signal, where the control parameters include a step value and an exposure time, and wherein, the step value is adjusted according to the distance between each sample point in the collection region, or the exposure time is adjusted according to the intensity value of the feedback signal.

[0063] In some embodiments, the sample measurement unit 510 includes a phase modulator module 512; the phase modulator module 512 is configured to perform beam splitting on the laser beam to obtain an array laser, and the array laser is used to perform laser irradiation on the sample points in the collection region.

[0064] It can be understood that in order to enable the laser to form an array of light on the surface of the sample, phase modulation can be used. A phase modulator is an optical device used to adjust the phase of light without changing the amplitude of the light. It changes the optical path of the light wave passing through the material through external influences such as electric fields, magnetic fields, acoustic waves, or temperature, thereby achieving phase modulation. In this embodiment, the phase modulator module 512 is used to split the laser beam, turning the light at one point into an array of light to obtain an array of lasers. Using the array of lasers to irradiate the sample points within the acquisition area is conducive to simultaneously collecting Raman spectral signals at multiple points on the sample at one time for statistical analysis, which is conducive to improving the measurement speed.

[0065] In some embodiments, the phase modulator module can be a spatial light modulator, a liquid crystal phase plate, a micro-mirror array, a Fresnel lens array, a diffractive optical element, a multi-focus lens, a holographic optical element, a planar waveguide array, a birefringent crystal array, a photonic crystal, an electro-optic beam shaper, a grating, etc.

[0066] In some embodiments, the signal processing unit 520 includes a signal conversion module, and the signal conversion module includes a spectrometer and a signal conversion device.

[0067] The spectrometer is used to collect the optical signals excited by the laser irradiation, split the collected optical signals into optical signals of multiple wavelengths, and output them to the signal conversion device; the signal conversion device is used to convert the optical signal of each wavelength into an electrical signal.

[0068] It can be understood that after irradiating multiple sample points with an array of light, the Raman scattering spectral optical signals emitted by the sample are collected and recorded by the spectrometer, and the Raman optical signals are split into signal lights of various wavelengths by the grating in the spectrometer and then output to the signal conversion device (which can be a photodetector). The signal conversion device converts the optical signal into an electrical signal. It can be understood that since Raman spectral optical signals are emitted simultaneously by multiple light points on the sample, when collecting signals, multiple optical signals are collected simultaneously. To ensure that each optical signal is accurately resolved and recorded, a spectrometer, including a microscopic objective lens, a beam splitter, an optical filter, etc., is usually used to separate the optical signals at different points.

[0069] Please refer to Figure 6 , Figure 6 which is a second structural schematic diagram of a substance concentration measurement system based on Raman spectroscopy.

[0070] After setting the parameters of the laser, the laser beam is emitted from the laser emitter 513. After passing through multiple lenses 514, and then through the adjustment of the phase modulator module 512 and the objective lens 515, the laser beam is focused on the solution sample to be measured 516, and a feedback signal (i.e., Raman spectral optical signal) is excited at the sample point of the solution sample to be measured 516. The feedback signal passes through the sample measurement unit 510 and enters the signal processing unit 520. The feedback signal is divided into optical signals of multiple wavelengths by the spectrometer 522, and then each optical signal of each wavelength is converted into an electrical signal by the signal conversion device 521. The signal processing unit 520 measures the concentration of the target substance in the solution sample to be measured according to the electrical signal. When the sampling of the sample points in the first acquisition area is completed, the control program of the displacement stage 517 is automatically started to align it with the next acquisition area, as Figure 7 shown. The displacement stage 517 moves on the x-axis and y-axis according to the preset path, and so on, so that all the measured positions can be covered. Through the movement of the displacement stage 517, an automated capillary Raman optical field measurement is realized, and there is no need to manually adjust the position of the capillary.

[0071] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of this application and the above drawings are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of this application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0072] It should be understood that in this application, "at least one (item)" means one or more, and "a plurality" means two or more. "And / or" is used to describe the association relationship of associated objects and indicates that three relationships can exist. For example, "A and / or B" can mean: only A exists, only B exists, and both A and B exist at the same time. Among them, A and B can be singular or plural. The character " / " generally means that the associated objects before and after are in an "or" relationship. "At least one (one) of the following" or its similar expression means any combination of these items, including any combination of single item (one) or plural items (ones). For example, at least one (one) of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0073] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be an indirect coupling or communication connection through some interfaces, devices, or units, and can be in electrical, mechanical, or other forms.

[0074] In addition, in each embodiment of the present application, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

[0075] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM), random access memories (RAM), magnetic disks, or optical discs that can store program codes.

[0076] Although the description of the present application has been quite detailed and has particularly described several of the described embodiments, it is not intended to be limited to any of these details or embodiments or any particular embodiment. Instead, it should be regarded as effectively covering the intended scope of the present application by referring to the appended claims and considering the broad possibilities of interpretation of these claims in light of the prior art. In addition, the present application is described above with embodiments foreseeable by the inventors for the purpose of providing a useful description, and those non-substantive modifications to the present application that are not currently foreseeable can still represent equivalent modifications of the present application.

Claims

1. A method for measuring substance concentration based on Raman spectroscopy, characterized in that: The method comprises: Dividing the solution sample to be tested into samples in a plurality of collection areas, each sample in the collection area includes a plurality of sample points; According to a preset array rule, laser irradiation is performed on the samples in each of the collection areas to obtain a plurality of optical signal arrays corresponding to the array rule; When the collection area is irradiated with laser, the optical signal corresponding to each sample point in the collection area is collected and an optical signal array corresponding to the collection area is generated; Generate a target signal set based on the optical signal array corresponding to each of the acquisition areas; Based on the mapping relationship between the target signal and the target substance in the target signal set, the concentration of the target substance in the solution sample to be tested is determined.

2. The method for measuring substance concentration based on Raman spectroscopy according to claim 1, characterized in that: Generating a target signal set based on the optical signal array corresponding to each of the acquisition areas includes: According to the target substance, the optical signal array corresponding to each of the collection areas is identified using a preset threshold; Determine whether each optical signal in the optical signal array is an optical signal corresponding to the target substance, and if so, generate a first digital signal; if not, generate a second digital signal; The target signal set is generated based on a plurality of the first digital signals and a plurality of the second digital signals.

3. The method for measuring substance concentration based on Raman spectroscopy according to claim 2, characterized in that: The determining the concentration of the target substance in the solution sample to be tested based on the mapping relationship between the target signal in the target signal set and the target substance comprises: Determine a proportion of the first digital signal in the target signal set; generating a linear relationship between the ratio value and the concentration of the molecule in a logarithmic coordinate system; Based on the linear relationship between the ratio value and the molecular concentration in the logarithmic coordinate system, a preset prediction model is used to predict and determine the concentration of the target substance in the solution sample to be tested.

4. The method for measuring substance concentration based on Raman spectroscopy according to claim 1, characterized in that: The method comprises: Setting the collection area; The step of setting the acquisition area comprises: generating a laser beam based on a preset intensity and a preset focal length; Determining the coordinate value range of the focus of the laser beam according to the position of the target sample point; Based on the coordinate value range, determining the acquisition area; When the laser beam is used to perform a laser irradiation operation on each sample point in the acquisition area, a feedback signal is obtained and a control parameter of the laser irradiation operation is adjusted according to the feedback signal, wherein the control parameter includes a step value and an exposure time, wherein: The step value is adjusted according to the distance between each sample point in the acquisition area, or, The exposure time is adjusted according to the intensity value of the feedback signal.

5. A substance concentration measurement system based on Raman spectroscopy, characterized in that: The system includes a sample measurement unit and a signal processing unit; The sample measurement unit is used to divide the solution sample to be tested into samples in a plurality of collection areas, each sample in the collection area includes a plurality of sample points; according to a preset array rule, laser irradiation is performed on the sample in each collection area to obtain a plurality of optical signal arrays corresponding to the array rule; when the collection area is laser irradiated, the optical signal corresponding to each sample point in the collection area is collected and an optical signal array corresponding to the collection area is generated; The signal processing unit is used to generate a target signal set based on the optical signal array corresponding to each of the acquisition areas; Based on the mapping relationship between the target signal and the target substance in the target signal set, the concentration of the target substance in the solution sample to be tested is determined.

6. The substance concentration measurement system based on Raman spectroscopy according to claim 5, characterized in that: The signal processing unit is also used for: According to the target substance, the optical signal array corresponding to each of the collection areas is identified using a preset threshold; Determine whether each optical signal in the optical signal array is an optical signal corresponding to the target substance, and if so, generate a first digital signal; if not, generate a second digital signal; The target signal set is generated based on a plurality of the first digital signals and a plurality of the second digital signals.

7. The substance concentration measurement system based on Raman spectroscopy according to claim 6, characterized in that: The signal processing unit is also used for: Determine a proportion of the first digital signal in the target signal set; generating a linear relationship between the ratio value and the concentration of the molecule in a logarithmic coordinate system; Based on the linear relationship between the ratio value and the molecular concentration in the logarithmic coordinate system, a preset prediction model is used to predict and determine the concentration of the target substance in the solution sample to be tested.

8. The substance concentration measurement system based on Raman spectroscopy according to claim 5, characterized in that: The sample measurement unit is also used for: generating a laser beam based on a preset intensity and a preset focal length; Determining the coordinate value range of the focus of the laser beam according to the position of the target sample point; Based on the coordinate value range, determining the acquisition area; When the laser beam is used to perform a laser irradiation operation on each sample point in the acquisition area, a feedback signal is obtained and a control parameter of the laser irradiation operation is adjusted according to the feedback signal, wherein the control parameter includes a step value and an exposure time, wherein: The step value is adjusted according to the distance between each sample point in the acquisition area, or, The exposure time is adjusted according to the intensity value of the feedback signal.

9. The substance concentration measurement system based on Raman spectroscopy according to claim 8, characterized in that: The sample measurement unit includes a phase modulator module; The phase modulator module is used to perform a splitting process on the laser beam to obtain an array laser, and the array laser is used to perform laser irradiation on the sample points in the collection area.

10. The substance concentration measurement system based on Raman spectroscopy according to claim 8, characterized in that: The signal processing unit includes a signal conversion module, and the signal conversion module includes a spectrometer and a signal conversion device; The spectrometer is used to collect the optical signal excited by the laser irradiation, split the collected optical signal into optical signals of multiple wavelengths and output them to the signal conversion device; The signal conversion device is used to convert the optical signal of each wavelength into an electrical signal.

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