Three-dimensional fluorescence detection apparatus

Abstract

A three-dimensional fluorescence detection apparatus, comprising a monochromatic array light source, a first lens group, a fluorescence detection apparatus, a light intensity detection apparatus, and a control and data processing module. The monochromatic array light source is used for emitting excitation light, and comprises N monochromatic light sources, wherein the excitation light comprises light of N wavelengths, and covers a first waveband; the first lens group is used for converging the excitation light to form an excitation region in which a sample to be subjected to detection is placed; the fluorescence detection apparatus is used for outputting fluorescence spectrum data; the light intensity detection apparatus is used for outputting transmission light intensity data; and the control and data processing module is used for controlling the monochromatic array light source to emit excitation light, and is also used for determining the three-dimensional fluorescence spectrum and absorption spectrum of said sample. Fluorescence spectrum data and transmission light intensity data of a sample are acquired by means of synchronous sampling, such that the absorption spectrum and three-dimensional fluorescence spectrum of the sample are synchronously detected. Thus, the accuracy of substance detection for the sample can be improved, and the size, cost and power consumption of a system are also reduced.

Description

A three-dimensional fluorescence detection device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on July 14, 2023, with application number 202310864491.3, and priority to the Chinese patent application entitled “A Three-Dimensional Fluorescence Detection Device”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of light perception, and more specifically, to a three-dimensional fluorescence detection device. Background Art

[0003] Using spectroscopy to determine the composition and content of substances has long been a key area of ​​research in the field of optical sensing. The most commonly used spectral detection techniques involve analyzing absorption and fluorescence spectra. The basic principle is that a light beam passes through or illuminates a sample. The substance in the sample absorbs photons within a specific spectral range, causing the spectrum of the incident beam to change. Alternatively, the substance in the sample absorbs photons and then radiates fluorescence within a specific spectral range. The composition and content of the substance in the sample can be determined by studying the absorption spectrum transmitted by the sample or the fluorescence spectrum emitted by the sample.

[0004] In the actual detection process, unknown samples are often complex mixtures of multiple substances. For example, when detecting organic pollutants in water, the spectral information of various substances is superimposed on each other. The information provided by a simple fluorescence spectrum or absorption spectrum is often relatively simple and cannot accurately identify and analyze the sample.

[0005] Three-dimensional fluorescence spectroscopy, a "fingerprint spectrum," adds the excitation wavelength dimension to a conventional two-dimensional fluorescence spectrum, creating a three-dimensional matrix spectrum (EES). Typically, the y-axis corresponds to the excitation wavelength, the x-axis to the fluorescence emission wavelength, and the z-axis to the fluorescence intensity. Three-dimensional fluorescence spectroscopy captures the total fluorescence data of a sample and offers advantages for analyzing the substance class and extracting information about its composition.

[0006] However, the acquisition of a substance's three-dimensional fluorescence spectrum relies on expensive and bulky laboratory instruments. These instruments generally require professional personnel to operate and maintain, making it difficult to achieve commercial and industrial applications outside the laboratory. Moreover, these three-dimensional fluorescence spectrum detection instruments can often only obtain three-dimensional fluorescence spectra. If you want to obtain the absorption spectrum of the sample, you need to use an absorption spectrum detection instrument. For some samples with unstable properties, such as suspensions and colloids, it is impossible to simultaneously obtain the absorption spectrum and three-dimensional fluorescence spectrum of the sample in the same state. Therefore, the miniaturization, low cost and ease of operation of three-dimensional fluorescence detection instruments have been hot research directions in recent years; and how to obtain the absorption spectrum and three-dimensional fluorescence spectrum of the sample under the same experimental conditions has also been an urgent problem that needs to be solved in recent years.

[0007] Summary of the Invention

[0008] This application provides a three-dimensional fluorescence detection device. It utilizes a monochromatic array light source instead of a traditional high-power xenon lamp and monochromator, significantly reducing system size, cost, and power consumption, thereby facilitating the integration and application of three-dimensional fluorescence spectrum detection technology. Furthermore, this application utilizes a fluorescence detection device and a light intensity detection device for simultaneous sampling, detecting both the absorption spectrum and the three-dimensional fluorescence spectrum of a sample, thereby improving the accuracy of sample material detection.

[0009] In a first aspect, a three-dimensional fluorescence detection device is provided, comprising a monochromatic array light source, a first lens group, a fluorescence detection device, a light intensity detection device, and a control and data processing module. Specifically, the monochromatic array light source is configured to emit excitation light, the monochromatic array light source comprising N monochromatic light sources configured to emit light having a single wavelength, the excitation light comprising N wavelengths of light covering a first wavelength band, wherein N is a positive integer greater than or equal to 2, and the first wavelength band intersects with the fluorescence excitation wavelength band of a sample to be tested; the first lens group is configured to receive the excitation light and converge and overlap the excitation light to form an excitation region, wherein the N beams of excitation light enter the first lens group at different incident positions, and the sample to be tested is placed in the excitation region; the fluorescence detection device is configured to receive a fluorescence signal generated by the sample to be tested and output fluorescence spectrum data, and the light intensity detection device is configured to receive the excitation light transmitted from the sample to be tested and output transmitted light intensity data; the control and data processing module is configured to control the monochromatic array light source to emit excitation light, and is further configured to receive the fluorescence spectrum data and transmitted light intensity data to determine a three-dimensional fluorescence spectrum and absorption spectrum of the sample to be tested.

[0010] Based on this technical solution, a monochromatic array light source is used to emit excitation light. The monochromatic array light source includes N monochromatic light sources, each of which emits light of a single wavelength. The excitation light band emitted by the entire monochromatic array light source covers the first band. The first lens group converges the excitation light emitted by the array light source to form an excitation zone, which is used to place the sample to be tested so that the sample generates fluorescence through stimulated radiation. By synchronously sampling and acquiring the fluorescence spectrum data and transmitted light intensity data of the sample through a fluorescence detection device and a light intensity detection device, and synchronously detecting the absorption spectrum and three-dimensional fluorescence spectrum of the sample, the accuracy of sample substance detection can be improved, while also reducing the size, cost, and power consumption of the system, in order to facilitate the integration and application of three-dimensional fluorescence spectrum detection technology.

[0011] It should be understood that in the embodiment of the present application, the fluorescence spectrum data includes the composition of the fluorescence bands in the fluorescence signal and the light intensity of the fluorescence in each band.

[0012] It should be understood that the light intensity detection device can be set on the side of the excitation light transmission direction, and the fluorescence detection device can be set on the side of the excitation area, and the side of the excitation light transmission direction and the side of the excitation area are adjacent.

[0013] It should be understood that in the embodiment of the present application, the first band includes the infrared-near infrared-ultraviolet UV-VIS-NIR band. Specifically, in practical applications, the coverage range of the first band can be determined according to the characteristics of the stimulated radiation of the sample to be tested to ensure that the sample to be tested generates a fluorescence signal by stimulated radiation in the excitation area. This application does not impose any special restrictions on this.

[0014] It should be understood that the monochromatic array light source is composed of N monochromatic light sources, and the N wavelengths of light emitted by the N monochromatic light sources have a first interval in sequence, and the spectrum of the excitation light emitted by the overall monochromatic array light source covers the first band. In the embodiment of the present application, N includes a positive integer greater than or equal to 3, and the present application does not make any special limitations on this.

[0015] It should be understood that when the first interval is smaller, that is, the number of monochromatic light sources in the first band is greater, and the value of N is larger, the more fluorescence spectrum data and transmitted light intensity data points are obtained, and the accuracy of the generated three-dimensional fluorescence spectrum and absorption spectrum is higher. In the embodiment of the present application, the first interval includes 10 to 20 nm. The specific value of the first interval can be determined according to the characteristics of the stimulated radiation of the sample to be tested to ensure that the obtained three-dimensional fluorescence spectrum data and absorption spectrum have a certain continuity. This application does not make any special restrictions on this.

[0016] It should be understood that when N=1, that is, the monochromatic array light source emits excitation light with only one wavelength, the sample to be tested generates a fluorescence signal due to the excitation light, the fluorescence spectrum data and transmitted light intensity data received by the control and data processing module only include data points of one wavelength, and the wavelength coordinates of the generated three-dimensional fluorescence spectrum and absorption spectrum only include data points of one wavelength.

[0017] In combination with the first aspect, in certain implementations of the first aspect, the N wavelengths of light emitted by N monochromatic light sources have a first wavelength interval in sequence, and also includes that when N is greater than or equal to 3, the nth monochromatic light source emits light with a first wavelength, the n+1th monochromatic light source emits light with a second wavelength, and the n+2th monochromatic light source emits light with a third wavelength, and n, n+1, and n+2 are positive integers belonging to N; wherein the difference between the first wavelength and the second wavelength is a first value, the difference between the second wavelength and the third wavelength is a second value, and the first wavelength interval includes the first value and the second value.

[0018] Based on this technical solution, a monochromatic array light source is used to emit excitation light. The monochromatic array light source includes N monochromatic light sources, each of which emits light of a single wavelength. The excitation light band emitted by the entire monochromatic array light source covers the first band. The first lens group converges the excitation light emitted by the array light source to form an excitation zone, which is used to place the sample to be tested so that the sample generates fluorescence through stimulated radiation. By synchronously sampling and acquiring the fluorescence spectrum data and transmitted light intensity data of the sample through a fluorescence detection device and a light intensity detection device, and synchronously detecting the absorption spectrum and three-dimensional fluorescence spectrum of the sample, the accuracy of sample substance detection can be improved, while also reducing the size, cost, and power consumption of the system, in order to facilitate the integration and application of three-dimensional fluorescence spectrum detection technology.

[0019] It should be understood that the first value and the second value can be the same value or different values, that is, the wavelength interval between each monochromatic light source can be fixed, and the excitation light emitted by N monochromatic light sources covers the first band; it is also possible that the wavelength interval between each monochromatic light source is different, and the excitation light emitted by N monochromatic light sources covers the first band; this application does not make any special restrictions on this.

[0020] In combination with the first aspect, in certain implementations of the first aspect, the light emitted by N monochromatic light sources is directly coupled through N optical fibers, and the N optical fibers transmit the excitation light emitted by the monochromatic array light source to the first lens group, and the output ends of the N optical fibers are arranged nonlinearly.

[0021] Based on this technical solution, the light emitted by N monochromatic light sources is directly coupled through N optical fibers respectively, and the coupled excitation light is transmitted to the first lens group through the optical fiber bundle. The output end of the optical fiber bundle formed by the N optical fibers is arranged nonlinearly. By adopting the method of directly coupling the monochromatic light source with the optical fiber, no other coupling device is required, which simplifies the design of the overall device. Especially when the number of monochromatic light sources is large, that is, N is large, the direct coupling method can greatly simplify operations such as aligning the optical path. By synchronously sampling and acquiring the fluorescence spectrum data and transmitted light intensity data of the sample through the fluorescence detection device and the light intensity detection device, and synchronously detecting the absorption spectrum and three-dimensional fluorescence spectrum of the sample, the accuracy of the sample substance detection can be improved, while also reducing the volume, cost and power consumption of the system, so as to facilitate the integration and application of the three-dimensional fluorescence spectrum detection technology.

[0022] In combination with the first aspect, in certain implementations of the first aspect, light emitted by N monochromatic light sources is coupled into N optical fibers through N coupling lenses respectively. The N optical fibers transmit the excitation light emitted by the monochromatic array light source to the first lens group, and the output ends of the N optical fibers are arranged nonlinearly.

[0023] Based on this technical solution, the light emitted by N monochromatic light sources is coupled into N optical fibers through N coupling lenses, and the coupled excitation light is transmitted to the first lens group through the optical fiber bundle. The output end of the optical fiber bundle formed by the N optical fibers is nonlinearly arranged. The use of coupling lenses to couple the light emitted by the monochromatic light source into the N optical fibers can further improve the optical fiber coupling efficiency and the beam quality of the excitation light beam incident on the sample area. By synchronously sampling and acquiring the fluorescence spectrum data and transmitted light intensity data of the sample through the fluorescence detection device and the light intensity detection device, and synchronously detecting the absorption spectrum and three-dimensional fluorescence spectrum of the sample, the accuracy of the sample substance detection can be improved, while also reducing the volume, cost, and power consumption of the system, so as to facilitate the integration and application of three-dimensional fluorescence spectrum detection technology.

[0024] In combination with the first aspect, in certain implementations of the first aspect, the output ends of the N optical fibers are arranged in a close arrangement, wherein the close arrangement includes the output end cross-section formed by the N optical fibers being arranged with the smallest surface area, and the output end cross-section includes a circle.

[0025] Based on this technical solution, the output ends of N optical fibers are closely arranged to minimize the surface area of ​​the end face, resulting in a circular end face. This further improves the beam quality of the excitation beam incident on the sample area. By synchronously sampling and acquiring fluorescence spectrum data and transmitted light intensity data from the sample using a fluorescence detection device and a light intensity detection device, and simultaneously detecting the sample's absorption spectrum and three-dimensional fluorescence spectrum, the accuracy of sample material detection can be improved while also reducing the system's size, cost, and power consumption, thereby facilitating the integration and application of three-dimensional fluorescence spectroscopy detection technology.

[0026] In combination with the first aspect, in certain implementations of the first aspect, the three-dimensional fluorescence detection device also includes a second lens group, which is used to converge the excitation light transmitted from the sample to be tested to the receiving target surface of the light intensity detection device, and the diameter of the light spot formed by the convergence of the excitation light is less than or equal to the diameter of the photosensitive area of ​​the receiving target surface.

[0027] Based on this technical solution, the 3D fluorescence detection device also includes a second lens group. The excitation light transmitted from the sample is further diverged. The diverged transmitted light is then converged again by the second lens group and converged onto the receiving target surface of the light intensity detection device. By synchronously sampling the fluorescence spectrum data and transmitted light intensity data of the sample by the fluorescence detection device and the light intensity detection device, and simultaneously detecting the sample's absorption spectrum and 3D fluorescence spectrum, the accuracy of sample material detection can be improved while also reducing the system's size, cost, and power consumption, thereby facilitating the integration and application of 3D fluorescence spectroscopy detection technology.

[0028] In combination with the first aspect, in certain implementations of the first aspect, the control and data processing module is used to control the monochromatic array light source to emit excitation light, and the control and data processing module sends a driving signal to the monochromatic array light source, and the driving signal includes a square wave pulse signal. The driving signal is used to drive N monochromatic light sources to emit light in sequence, and the light-emitting duration of the monochromatic light source is the pulse duration of the square wave pulse signal.

[0029] Based on this technical solution, the N monochromatic light sources in the array are sequentially driven to emit light, and the fluorescence detection device and light intensity detection device also sequentially receive the detected fluorescence signals and light intensity signals, thereby corresponding the fluorescence spectrum data and transmitted light intensity data to the wavelength of the monochromatic light source. By synchronously sampling and acquiring the fluorescence spectrum data and transmitted light intensity data of the sample by the fluorescence detection device and the light intensity detection device, and simultaneously detecting the sample's absorption spectrum and three-dimensional fluorescence spectrum, the accuracy of sample material detection can be improved, while also reducing the system size, cost, and power consumption, thereby facilitating the integration and application of three-dimensional fluorescence spectroscopy detection technology.

[0030] In combination with the first aspect, in some implementations of the first aspect, the control and data processing module is further used to send a synchronization trigger instruction to the fluorescence detection device to start the fluorescence detection device to sequentially receive the pulse fluorescence signals generated by the excitation area.

[0031] Based on this technical solution, the N monochromatic light sources in the array are sequentially driven to emit light. The fluorescence detection device also receives a synchronous trigger command, begins detecting the fluorescence signal, and converts the fluorescence spectrum data into fluorescence spectrum data. By synchronously sampling the fluorescence spectrum data and transmitted light intensity data of the sample with the fluorescence detection device and the light intensity detection device, and simultaneously detecting the sample's absorption spectrum and three-dimensional fluorescence spectrum, the accuracy of sample material detection can be improved while also reducing the system's size, cost, and power consumption, thereby facilitating the integration and application of three-dimensional fluorescence spectroscopy detection technology.

[0032] In combination with the first aspect, in certain implementations of the first aspect, the fluorescence detection device includes a fiber optic probe and a spectrometer, the fiber optic probe is used to obtain the fluorescence signal generated by the excitation area, and the spectrometer is used to obtain the composition of the fluorescence bands in the fluorescence signal and the light intensity of the fluorescence in each band.

[0033] Based on this technical solution, the fluorescence detection device includes a fiber optic probe and a spectrometer. The fiber optic probe is positioned on one side of the sample area to capture the fluorescence signal generated by the sample's stimulated radiation. After receiving the fluorescence signal, the spectrometer converts it into fluorescence spectral data, which includes the composition of wavelengths and the corresponding light intensity of each wavelength. By synchronously sampling the fluorescence spectrum data and transmitted light intensity data of the sample with the fluorescence detection device and the light intensity detection device, and simultaneously detecting the sample's absorption spectrum and three-dimensional fluorescence spectrum, the accuracy of sample material detection can be improved while also reducing the system's size, cost, and power consumption, thereby facilitating the integration and application of three-dimensional fluorescence spectroscopy detection technology.

[0034] In combination with the first aspect, in certain implementations of the first aspect, the optical fiber probe includes a single-core fluorescent optical fiber probe, the input end of the single-core fluorescent optical fiber probe directly detects the fluorescence signal generated by the excitation region, and the output end of the single-core fluorescent optical fiber probe is directly connected to the optical fiber probe interface of the spectrometer.

[0035] Based on this technical solution, the fiber optic probe includes a single-core fluorescence fiber probe. The probe's input end is located on one side of the excitation zone to detect the fluorescence signal generated by the sample, and the probe's output end is directly connected to a spectrometer. By synchronously sampling the sample's fluorescence spectrum and transmitted light intensity data through a fluorescence detection device and a light intensity detection device, and simultaneously detecting the sample's absorption spectrum and three-dimensional fluorescence spectrum, the accuracy of sample material detection can be improved while also reducing the system's size, cost, and power consumption, facilitating the integration and application of three-dimensional fluorescence spectroscopy detection technology.

[0036] In combination with the first aspect, in certain implementations of the first aspect, the optical fiber probe includes a multi-core fluorescent optical fiber probe, which includes three or more single-core optical fibers. The single-core optical fibers are arranged in a tightly packed manner to form the input end of the multi-core fluorescent probe, and the input end is used to detect the fluorescence signal generated in the excitation area; the single-core optical fibers are arranged in a linear manner to form the output end of the multi-core fluorescent probe, and the output end is connected to the optical fiber probe interface of the spectrometer.

[0037] Based on this technical solution, the fiber optic probe includes a multi-core fluorescence fiber optic probe. The probe's input end is composed of tightly packed, circular-shaped optical fibers. The output end is linearly arranged according to the spectrometer's slit interface, further reducing light loss. By synchronously sampling the sample's fluorescence spectrum and transmitted light intensity data through fluorescence and light intensity detection devices, and simultaneously detecting the sample's absorption spectrum and three-dimensional fluorescence spectrum, the accuracy of sample material detection can be improved while also reducing the system's size, cost, and power consumption, facilitating the integration and application of three-dimensional fluorescence spectroscopy detection technology.

[0038] In combination with the first aspect, in certain implementations of the first aspect, a detection distance between the input end of the optical fiber probe and the excitation region includes 2×d×NA=D;

[0039] Where d is the detection distance, NA is the numerical aperture of the fiber probe, and D is the diameter of the spot formed by the excitation light converged in the excitation area.

[0040] Based on this technical solution, the excitation light is converged and overlapped through the first lens group to form an excitation area. The spot diameter of the excitation area is D. The optical fiber probe is set on one side of the excitation area, and the detection distance between it and the excitation area should satisfy 2×d×NA=D; where d is the detection distance and NA is the numerical aperture of the optical fiber probe. When the optical fiber probe is at a suitable detection distance, the conical solid angle received by the probe can cover the entire fluorescence excitation area to increase the detection efficiency. By synchronously sampling the fluorescence spectrum data and the transmitted light intensity data of the sample through the fluorescence detection device and the light intensity detection device, and synchronously detecting the absorption spectrum and three-dimensional fluorescence spectrum of the sample, the accuracy of the sample material detection can be improved, while also reducing the volume, cost and power consumption of the system, so as to facilitate the integration and application of the three-dimensional fluorescence spectrum detection technology.

[0041] In combination with the first aspect, in certain implementations of the first aspect, the light intensity detection device includes a photodetector and an amplifying circuit, the photodetector is used to receive excitation light transmitted from the sample to be tested and convert the received light signal into an electrical signal; the amplifying circuit is used to amplify the electrical signal.

[0042] Based on this technical solution, the light intensity detection device includes a photodetector and an amplifier circuit. The light intensity detector's receiving target surface receives the transmitted light beam converged by the second lens group and converts the received optical signal into an electrical signal. The amplifier circuit amplifies the electrical signal so that the control and data processing modules can obtain transmitted light intensity data. By synchronously sampling and acquiring fluorescence spectrum data and transmitted light intensity data from the sample through the fluorescence detection device and the light intensity detection device, and simultaneously detecting the sample's absorption spectrum and three-dimensional fluorescence spectrum, the accuracy of sample material detection can be improved while also reducing the system's size, cost, and power consumption, thereby facilitating the integration and application of three-dimensional fluorescence spectroscopy detection technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG1 is a schematic structural diagram of a commonly used high-power xenon lamp three-dimensional fluorescence detection device provided in an embodiment of the present application;

[0044] FIG2 is a schematic structural diagram of a commonly used LED array three-dimensional fluorescence detection device provided in an embodiment of the present application;

[0045] FIG3 is a schematic structural diagram of a three-dimensional fluorescence detection device provided in an embodiment of the present application;

[0046] FIG4 is a schematic diagram of a light source coupling method in a three-dimensional fluorescence detection device provided in an embodiment of the present application;

[0047] FIG5 is a schematic diagram of another light source coupling method in a three-dimensional fluorescence detection device provided in an embodiment of the present application;

[0048] FIG6 is a schematic structural diagram of a lens assembly in a three-dimensional fluorescence detection device provided in an embodiment of the present application;

[0049] FIG7 is a schematic structural diagram of a spectrometer in a three-dimensional fluorescence detection device provided in an embodiment of the present application;

[0050] FIG8 is a schematic structural diagram of an optical fiber probe in a three-dimensional fluorescence detection device provided in an embodiment of the present application;

[0051] FIG9 is a schematic structural diagram of an optical fiber probe in another three-dimensional fluorescence detection device provided in an embodiment of the present application;

[0052] FIG10 is a schematic diagram of a driving signal for an array light source in a three-dimensional fluorescence detection device provided in an embodiment of the present application;

[0053] FIG11 is a three-dimensional fluorescence spectrum generated by detecting a sample using a three-dimensional fluorescence detection device provided in an embodiment of the present application;

[0054] FIG12 is an absorption spectrum generated by detecting a sample using a three-dimensional fluorescence detection device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0055] The technical solution in this application will be described below with reference to the accompanying drawings.

[0056] It should be noted that, in the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in this article is merely a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two, and “at least one” and “one or more” refer to one, two or more. The singular expressions “a”, “an”, “said”, “the” and “this” are intended to also include expressions such as “one or more”, unless there is a clear indication to the contrary in the context.

[0057] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in yet other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0058] In the description of the embodiments of the present application, the terms "up", "down", "left", "right", "vertical", "horizontal", etc. indicate orientations or positional relationships that are defined relative to the orientations or positions of the components schematically placed in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative descriptions and clarifications, rather than indicating or implying that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. They may change accordingly according to changes in the orientation of the components placed in the drawings, and therefore cannot be understood as limitations on the present application.

[0059] In the embodiments of the present application, the same reference numerals are used to represent the same component or the same element. In addition, the components in the drawings are not drawn to scale, and the sizes and dimensions of the components shown in the drawings are only exemplary and should not be understood as limiting the present application.

[0060] Spectroscopic technology has always been one of the important means of analyzing the composition and content of substances. Absorption spectroscopy and fluorescence spectroscopy are the two most commonly used spectroscopic techniques. Among them, the absorption spectrum is a spectrum produced when the incident light beam passes through the sample and the substances in the sample absorb photons in a specific spectral range, resulting in the light intensity of certain spectral ranges of the outgoing light beam being different from the light intensity of the spectral range of the incident light beam. The fluorescence spectrum is a spectrum produced when the incident light beam hits the sample and the substances in the sample absorb photons and then radiate fluorescence in a specific spectral range. The absorption and fluorescence spectra of the sample can be used to infer the composition and content of the substances in the sample. In practical applications, the unknown samples to be tested are often complex mixtures of multiple molecules. The spectral information of various molecules is superimposed, resulting in incomplete information from a simple absorption or fluorescence spectrum, making it difficult to accurately identify and analyze the sample components.

[0061] Three-dimensional fluorescence spectroscopy, a "fingerprint spectrum," offers unique advantages for addressing these challenges. It builds upon two-dimensional fluorescence spectroscopy by adding the excitation wavelength dimension to form a three-dimensional excitation-emission-matrix spectrum (EES). The y-axis generally corresponds to the excitation wavelength, the x-axis to the fluorescence emission wavelength, and the z-axis to the fluorescence intensity. Three-dimensional fluorescence spectroscopy can collect comprehensive fluorescence data from a sample, offering significant advantages for analyzing substance classification and extracting compositional information. However, traditional three-dimensional fluorescence spectroscopy techniques rely on expensive, bulky laboratory instruments that require specialized personnel for operation and maintenance, making them inaccessible to industrial and consumer applications. Furthermore, these three-dimensional fluorescence spectroscopy instruments often only produce three-dimensional fluorescence spectra; obtaining the sample's absorption spectrum requires a separate absorption spectroscopy instrument. For samples with unstable properties, such as suspensions and colloids, it's impossible to simultaneously obtain both the absorption spectrum and the three-dimensional fluorescence spectrum under the same conditions. Therefore, miniaturization, cost-effectiveness, and ease of operation of three-dimensional fluorescence instruments have been hot research areas in recent years. Furthermore, obtaining both the absorption spectrum and the three-dimensional fluorescence spectrum of a sample under the same experimental conditions has also been a pressing challenge.

[0062] FIG1 is a schematic diagram of the structure of a commonly used high-power xenon lamp three-dimensional fluorescence detection device provided in an embodiment of the present application. The three-dimensional fluorescence device in the figure uses a high-power xenon lamp as a light source, with a power consumption generally between 150W and 300W. The spectrum range emitted by the xenon lamp covers the ultraviolet-visible-near infrared (UV-VIS-NIR) band. As shown in the figure, the broad spectrum light emitted by the xenon lamp is scanned by a monochromator and focused by a lens group before being incident on the sample area. The monochromator 1 is used for time-sharing scanning and outputs monochromatic excitation light of 200-700nm. The monochromatic excitation light is focused by the lens group to excite the sample to produce broad spectrum fluorescence radiation. The generated broad spectrum fluorescence signal is filtered out by a filter to remove the wavelength of the excitation light. The filtered fluorescence signal is then incident on the monochromator 2 again for time-sharing scanning to obtain light signals of different wavelengths in the fluorescence signal. The light signals of different wavelengths output from the time-sharing scanning of the monochromator 2 are then measured by a photomultiplier tube to measure their light intensity values. In the high-power xenon lamp three-dimensional fluorescence detection device shown in the figure, monochromator 1 performs time-sharing scanning on the wavelength of the excitation light emitted by the xenon lamp light source to obtain the excitation wavelength value (i.e., the y-axis), monochromator 2 performs time-sharing scanning on the excited fluorescence signal and obtains the fluorescence wavelength value (i.e., the x-axis), and the photomultiplier tube measures the light intensity of the fluorescence signal output by monochromator 2 in time to obtain the fluorescence intensity value (i.e., the z-axis). The device described in the figure constitutes a three-dimensional fluorescence spectrum based on the above three dimensions.

[0063] Although the device in Figure 1 can obtain a three-dimensional fluorescence spectrum of a sample, the large size and high cost of the high-power xenon lamp and monochromator limit the device's usage scenarios and its portability. Moreover, due to the high cost, it can often only be used to test samples in the laboratory, with few commercial applications, and it is unable to detect the absorption spectrum of the sample.

[0064] FIG2 is a schematic structural diagram of a commonly used LED array three-dimensional fluorescence detection device provided in an embodiment of the present application. The three-dimensional fluorescence device in the figure uses a light-emitting diode (LED) array as a light source. Each LED outputs quasi-monochromatic excitation light, and the wavelength interval of the excitation light output by each LED is about 10 nm. The excitation light emitted by each LED is coupled to the corresponding optical fiber through the corresponding coupling lens. The excitation light emitted by N LEDs is coupled to N optical fibers through N coupling lenses; wherein, the N LEDs form an LED light source array, that is, the light output by the LED array is coupled to the optical fiber bundle through the coupling lens group, and the output ends of the N optical fibers are combined into an optical fiber cable and connected to the sample cell. The LEDs in the LED light source array are lit in a time-sharing manner to emit excitation light. The excitation light is transmitted to the sample cell through the optical fiber to excite the sample to radiate fluorescence. The generated fluorescence signal is again received by the optical fiber cable and input into the monochromator. The monochromator performs wavelength scanning on the fluorescence signal to obtain a fluorescence spectrum, and the photomultiplier tube measures the light intensity of the corresponding fluorescence signal. In this device, the fiber optic cables connecting the sample cell's excitation light correspond one-to-one with the fluorescence signal receiving fiber optic cables. This means that the fluorescence signal from each monochromatic LED is received by the corresponding receiving fiber and then transmitted to the monochromator and photomultiplier tube. When using this device to detect three-dimensional fluorescence spectra, the LED light source array is time-sharingly illuminated, reaching the sample cell to excite the sample. The monochromator then time-sharingly scans the fluorescence signal after excitation by the sample cell, obtaining information about the fluorescence signal's wavelength and intensity, generating a three-dimensional fluorescence spectrum.

[0065] Although the device shown in Figure 2 uses an LED array light source instead of a high-power xenon lamp, which can reduce the size of the light source to a certain extent, the device shown in Figure 2 uses fiber optic cables for both the excitation light input end and the fluorescence signal receiving end of the sample cell, and the incident excitation light and the outgoing fluorescence signal need to be relatively closely aligned. When the number of LEDs in the LED array light source is large, the design of the device is difficult. In addition, the fluorescence areas excited by the excitation light vary from sample to sample, meaning that the propagation direction of the generated fluorescence signal changes. This means that the propagation direction of the fluorescence signal differs from that of the excitation light, and the fiber optic cable cannot receive the fluorescence signal in the fluorescence action area. The device shown in Figure 2 is more suitable for use with uniform liquid samples and cannot detect the absorption spectrum of the sample.

[0066] Three-dimensional fluorescence spectroscopy is a new type of fingerprint spectrum with important applications in agricultural products, chemical products, and water quality testing. However, currently, three-dimensional fluorescence spectroscopy equipment is primarily specialized laboratory equipment, which is bulky and expensive, making it difficult to popularize. In recent years, some monochromatic light sources in the ultraviolet to near-infrared spectral range have made significant progress. For example, LED light sources have now achieved milliwatt-level light radiation at a wavelength of 220nm in the deep ultraviolet region.

[0067] Therefore, this application proposes a three-dimensional fluorescence detection device based on a monochromatic array light source. By using a monochromatic array light source instead of a traditional high-power xenon lamp and monochromator, the system size, cost, and power consumption are significantly reduced, facilitating the integration and application of three-dimensional fluorescence spectrum detection technology. Furthermore, this application utilizes a fluorescence detection device and a light intensity detection device to simultaneously sample and detect the sample's absorption and fluorescence spectra, thereby improving the accuracy of sample material detection.

[0068] The three-dimensional fluorescence detection device includes a monochromatic array light source, a first lens group, a fluorescence detection device, a second lens group, a light intensity detection device, and a control and data processing module. The monochromatic array light source is composed of N monochromatic light sources that emit a single wavelength, and the wavelength interval between each monochromatic light source is 10 to 20 nm. The wavelength range covered by the entire array light source can range from deep ultraviolet (for example, 200 nm) to near infrared (for example, 1000 nm). Driven by the control and data processing module, the array light source emits excitation light, and the light emitted by the N monochromatic light sources is coupled into N optical fibers. The output ends of the N optical fibers are closely arranged to form a combined multi-core optical fiber. The combined multi-core optical fiber inputs the excitation light emitted by the LED array light source into the first lens group. The first lens group converges the excitation light into the sample area, which is used to place the sample to be tested. The sample under test is excited by excitation light from a monochromatic array light source in the sample area, causing stimulated radiation to generate a fluorescence signal. A fluorescence detection device is installed in the sample area to detect the fluorescence signal generated by the sample. The fluorescence detection device converts the received fluorescence signal into fluorescence spectrum data. The fluorescence spectrum data includes the wavelength of each monochromatic fluorescence component of the fluorescence signal and the corresponding light intensity of each wavelength. The control and data processing module combines the sample fluorescence spectrum data output by the fluorescence detection device with the N excitation light wavelengths emitted by the N monochromatic light sources to form a three-dimensional fluorescence spectrum of the sample.

[0069] For samples permeable to excitation light, the excitation light is transmitted through the sample area and then diverges again. The diverged excitation light passes through the second lens group, which converges the excitation light onto the receiving target surface of the light intensity detection device. The light intensity detection device is used to detect the intensity corresponding to each single wavelength beam of the excitation light after it passes through the sample area. The control and data processing module obtains the sample's transmitted light intensity data detected by the light intensity detection device and forms the sample's absorption spectrum.

[0070] In one embodiment, a monochromatic array light source comprises N single-wavelength LEDs, each with a wavelength interval of 10 to 20 nm. The overall array light source covers a wavelength range from deep ultraviolet (e.g., 200 nm) to near infrared (e.g., 1000 nm). The single-wavelength excitation light emitted by each LED is coupled into an optical fiber, ultimately forming a combined multi-core fiber consisting of N optical fibers.

[0071] In one embodiment, a monochromatic array light source comprises N semiconductor laser diodes (LDs), each with a wavelength interval of 10 to 20 nm. The overall array light source covers a wavelength range from the deep ultraviolet (e.g., 200 nm) to the near infrared (e.g., 1000 nm). The single-wavelength excitation light emitted by each LD is coupled into an optical fiber, ultimately forming a combined multi-core fiber consisting of N optical fibers.

[0072] It should be understood that the monochromatic array light source of the present application also includes other monochromatic light sources. The present application does not give examples one by one here. The specific protection scope should be based on the claims, and the present application does not make any special limitations on this.

[0073] The following describes the specific implementation of the technical solution of the present application by taking a monochromatic LED array light source as an example.

[0074] Figure 3 is a schematic structural diagram of a three-dimensional fluorescence detection device provided by an embodiment of the present application. Among them, N LED light sources are coupled into N optical fibers through their respective coupling modules, and the output ends of the N optical fibers are closely packed to form a combined multi-core optical fiber. The control and data processing module sends a time-sharing pulse signal to the LED array light source, driving the N LEDs to emit pulse light in sequence in a time-sharing manner; at the same time, the control and data processing module also sends a synchronous trigger signal to the fluorescence detection device, triggering the fluorescence detection device to collect the fluorescence signal excited by the LED excitation light in the sample area. After the time-sharing drive scanning of the N LEDs is completed, the control and data processing module receives the fluorescence spectrum data output by the fluorescence detection device and the transmitted light intensity data output by the light intensity detection device, and finally generates a three-dimensional fluorescence spectrum and absorption spectrum of the sample.

[0075] The fluorescence detection device consists of a fiber optic probe and a spectrometer. A fluorescence window is positioned adjacent to the sample's fluorescence excitation region, and the fiber optic probe is placed against the fluorescence window for detection. The spectrometer receives synchronous trigger commands from the control and data processing module and measures the fluorescence signal collected by the fiber optic probe. The spectrometer measures the intensity of each wavelength component within the broad-spectrum fluorescence signal and transmits this fluorescence spectrum data to the control and data processing module. The control and data processing module generates a three-dimensional fluorescence spectrum of the sample based on the wavelength of the time-sharing excitation light and the wavelength and intensity of the corresponding fluorescence spectrum data.

[0076] In one embodiment, the spectrometer in the fluorescence detection device may alternatively include a filter-type multi-channel spectrometer, a micro-electromechanical system (MEMS), etc. The specific scope of protection shall be subject to the claims, and this application does not make any special limitation on this.

[0077] For samples that are permeable to excitation light, the excitation light emitted by N LED array light sources diverges again after passing through the sample area. The diverged excitation light is then converged onto the detection target surface of the light intensity detection device through a second lens group. The light intensity detection device includes a photodetector, which converts the optical signal into an electrical signal. After passing through a transimpedance amplifier (TIA), the signal is then sampled using analog-to-digital (AD) sampling to obtain the corresponding transmitted light intensity data. This collected light intensity data is then transmitted to a control and data processing module. This module generates the sample's absorption spectrum based on the time-sharing drive and the received transmitted light intensity information, combined with the intensity of the monochromatic excitation light emitted by the LED.

[0078] In one embodiment, the photoelectric detection device may alternatively include a PIN photodiode, a photomultiplier tube (PMT), etc. The specific scope of protection shall be subject to the claims, and this application does not impose any special limitation on this.

[0079] It should be understood that the single-wavelength excitation light emitted by each LED light source is transmitted through the optical fiber, converges to the sample area through the first lens group, and after passing through the lens group, the light beams of different wavelengths converge and overlap in the sample area, and the converged and overlapping area has a higher light power density; in some embodiments, the sample area is also referred to as a fluorescence excitation area, a stimulated radiation area, etc. The sample to be tested is placed in the fluorescence excitation area to be excited by the excitation light, and the light power density of the fluorescent signal stimulated to be radiated is also relatively high. Furthermore, the excitation lights of different wavelengths converge and overlap in the fluorescence excitation area, that is, the fluorescent radiation stimulated by the excitation lights of different wavelengths all originate from the same area of ​​the same sample, which makes it easier to collect the fluorescence signal for analysis, and the analysis results are more accurate.

[0080] It should be understood that the wavelength interval of each LED is 10 to 20 nm, the wavelength interval between each LED is not necessarily the same, and the number of LED light sources set in each band from ultraviolet to near-infrared is not necessarily the same. The specific scope of protection should be based on the claims, and this application does not make any special limitations on this.

[0081] It should be understood that the fluorescent window arrangement position described in FIG3 is merely illustrative and does not constitute any limitation on the scope of protection of the present application.

[0082] It should be understood that in some embodiments, the sample is also referred to as a sample to be tested, a sample, a sample to be tested, a substance to be tested, etc., which is only a name reference and does not constitute any limitation on the scope of protection of this application.

[0083] In one embodiment, as an alternative, since LEDs are surface light sources with large radiation divergence, the excitation light emitted by the LEDs is coupled into optical fibers for propagation. Fiber coupling is employed to improve the beam quality of the excitation light, enabling efficient fluorescence excitation of the sample. The LED light source and optical fiber can be coupled via a coupling module or directly via a large-core optical fiber. Specifically, several different LED light source coupling methods are described in conjunction with Figures 3, 4, and 5.

[0084] FIG4 is a schematic diagram of a light source coupling method in a three-dimensional fluorescence detection device provided in an embodiment of the present application. FIG4 adopts a method of using a lens as a coupling module to couple the excitation light emitted by the LED chip into the optical fiber; the lens coupling method is suitable for larger LED chips and optical fibers with smaller core diameters. For example, as a non-limiting embodiment, a chip with a chip diameter (or side length) of 1 mm, an optical fiber core diameter of 400 um, an LED radiation power of 10 mW, and a coupling lens with a special optical design for coupling can be used. Experimental measurements show that the coupling efficiency of this method can reach about 4%. The greater the radiation power of the LED, the higher the light extraction efficiency of the optical fiber; at the same time, the smaller the diameter of the LED chip and the larger the core diameter of the optical fiber, the higher the light extraction efficiency of the optical fiber coupling.

[0085] FIG5 is a schematic diagram of another light source coupling method in a three-dimensional fluorescence detection device provided in an embodiment of the present application. FIG5 adopts a method of coupling using a large core diameter optical fiber directly as a coupling module; the direct coupling method is suitable for smaller LED chips and larger core diameter optical fibers. For example, as a non-limiting embodiment, a chip with a chip diameter (or side length) of 500um, a core diameter of the optical fiber of 500um, a radiation power of the LED of 10mW, and an incident end face of the optical fiber 100um away from the LED chip can be used. The coupling efficiency of this direct coupling method is measured experimentally to be about 2%. The greater the radiation power of the LED, the higher the light extraction efficiency of the optical fiber; at the same time, the smaller the diameter of the LED chip and the larger the core diameter of the optical fiber, the higher the light extraction efficiency of the optical fiber coupling.

[0086] It should be understood that in specific embodiments, coupling through a coupling lens and direct coupling are applicable to different scenarios. Lens coupling has lower requirements on the size of the LED chip and the core diameter of the optical fiber, and the coupled light extraction efficiency is higher. However, lens coupling increases the complexity of the optical path and increases the difficulty of manufacturing. With the development of existing monochromatic light source technology, the light output power of existing LED chips is still relatively high, about 50mW, even near 250nm in the deep ultraviolet band. In some embodiments, direct optical fiber coupling can be used for coupling to ensure that the optical fiber coupling light output power reaches 500uW or more, so as to realize the detection of three-dimensional fluorescence spectrum and absorption spectrum. Furthermore, the direct coupling method can simplify the optical path and reduce the difficulty of instrument manufacturing, thereby further reducing the production cost of the instrument and increasing the application scenarios.

[0087] It should be understood that the cross-section of the combined multi-core optical fiber formed by the close arrangement of the optical fibers before entering the first lens group is shown in Figures 4 and 5. The close arrangement of the combined multi-core optical fiber is to minimize the cross-sectional area to facilitate the optical design after the optical path. As a non-limiting example, 20-30 LED monochromatic light sources are used as array light sources in this application, and the cross-sectional diameter of the multi-core optical fiber formed is about 3 mm. The cross-sections in the drawings of this application are only schematic diagrams of one possible embodiment and do not constitute any limitation on the scope of protection of this application.

[0088] Figure 6 is a schematic diagram of the structure of a lens group in a three-dimensional fluorescence detection device provided in an embodiment of the present application. The excitation light emitted by the array light source through the multi-core optical fiber is converged to the sample area through the first lens group, and the excitation light transmitted from the sample area is converged to the target surface of the photodetector through the second lens group. Among them, the sample area, that is, the fluorescence excitation area, that is, the area where the N excitation light beams of the first lens group converge and overlap, should be formed with a light spot diameter as small as possible to ensure that the fluorescence excitation area has sufficient excitation light power density. The excitation light will diverge rapidly after passing through the sample area, and the divergent N beams of excitation light will converge again through the second lens group. Similarly, the light spot diameter formed in the area where the excitation light converges after passing through the second lens group should also be as small as possible, and the light spot diameter formed should be smaller than the diameter of the detector target surface. The lens group in the drawings of the present application is only a schematic diagram of a possible implementation method and does not constitute any limitation on the scope of protection of the present application.

[0089] As a non-limiting example, in this application, the excitation light forms a spot of approximately 2 mm in the fluorescence excitation region after passing through the first lens group, and forms a spot of approximately 3 mm on the photodetector target surface after passing through the second lens group. It should be understood that the diameter of the photosensitive region target surface of the photodetector used in this application is greater than 3 mm.

[0090] The sample to be tested is placed in the fluorescence excitation zone. The excited fluorescence signal radiates throughout the entire space within a 4π solid angle. A fluorescence probe can only receive a portion of the fluorescence signal. The main factors affecting the fluorescence probe's reception efficiency include the core diameter end face area of ​​the fiber probe, the numerical aperture (NA), and the distance between the fiber probe end face and the fluorescence excitation zone.

[0091] As a non-limiting example, in this application, N excitation lights emitted by the array light source converge in the fluorescence excitation region, and the diameter of the beam formed by the convergence in the overlap region is about 2 mm. When the NA of the optical fiber probe is 0.22, in order to ensure that the cone solid angle received by the optical fiber probe covers the entire fluorescence excitation region, the distance d between the probe and the fluorescence excitation region needs to satisfy: 2×d×NA=2mm (1)

[0092] From formula (1), we can calculate that d = 4.55 mm. Therefore, in actual design, the distance between the fiber optic probe and the fluorescence excitation area can be selected to be slightly larger than the above theoretical distance. That is, the distance between the fiber optic probe and the fluorescence excitation area can be set to 5 mm to ensure that the receiving range of the fiber optic probe can cover the fluorescence excitation area.

[0093] Figure 7 is a structural schematic diagram of a spectrometer in a three-dimensional fluorescence detection device provided by an embodiment of the present application. The spectrometer receives the fluorescence signal detected by the optical fiber probe from the optical fiber probe interface, and receives the synchronization trigger instruction issued by the control and data processing module from the trigger port. The spectrometer is used to detect and analyze the wavelength composition of the detected fluorescence signal and the fluorescence intensity corresponding to each wavelength. The fluorescence signal diverges from the optical fiber output end of the optical fiber probe and enters the spectrometer, that is, the fluorescence signal diverges from the optical fiber probe interface and is incident on the M1 spherical reflector of the spectrometer. The M1 spherical reflector collimates the divergent fluorescence signal, and the collimated fluorescence signal is incident on the grating. The grating disperses the wide-spectrum fluorescence signal and then is incident on the M2 spherical reflector. Since the fluorescence signals of specific wavelengths incident on the M2 spherical reflector are parallel to each other, the fluorescence signals of different wavelengths are focused on the focal plane by the M2 spherical reflector and separated from each other in space. By placing the detector on the focal plane of the M2 spherical reflector and receiving focused fluorescence signals of different wavelengths, the composition of the light signals of each wavelength in the wide-spectrum fluorescence signal and the corresponding light intensity of the light signals of each wavelength can be measured to obtain the spectrum of the fluorescence signal.

[0094] In one embodiment, the detection device may alternatively include a linear array photoelectric detector, a planar array photoelectric detector, etc. The specific scope of protection shall be subject to the claims, and this application does not impose any special limitation on this.

[0095] 6 and 7 , one end of the optical fiber probe is used to obtain the fluorescence signal in the fluorescence excitation area, and the other end is used to input the obtained fluorescence signal into the spectrometer through the optical fiber probe interface of the spectrometer. The spectrometer performs wavelength component analysis on the received fluorescence signal and the light intensity of the fluorescence signal corresponding to each wavelength.

[0096] In one embodiment, the optical fiber probe may alternatively include a single-core fluorescent optical fiber probe, a multi-core fluorescent optical fiber probe, etc. The specific scope of protection shall be subject to the claims, and this application does not impose any special restrictions on this. The following will explain the structures of two possible fluorescent probes in conjunction with Figures 8 and 9.

[0097] Figure 8 is a schematic diagram of the structure of a fiber optic probe in a three-dimensional fluorescence detection device provided in an embodiment of the present application. The single-core fluorescent fiber probe used in Figure 8 is a single-core fluorescent fiber probe. When a single-core optical fiber is used as a fluorescent fiber probe, a single-core optical fiber with a large core diameter needs to be selected. One end of the single-core optical fiber with a large core diameter is used to obtain the fluorescence signal of the fluorescence excitation area (receiving end), and the other end is connected to the optical fiber probe interface of the spectrometer (output end) to transmit the collected fluorescence signal to the spectrometer. As a non-limiting embodiment, in this application, the diameter of the large-core single-core optical fiber used is 1 mm, and it is directly connected to the probe interface of the spectrometer through the output end of the optical fiber (1 mm aperture).

[0098] In one embodiment, since the probe interface of the spectrometer can have various shapes, such as circular and slit, an optical design can be performed at the output end of the optical fiber to ensure light propagation efficiency, combining the shape of the spectrometer probe interface. This ensures the signal quality of the fluorescence signal received by the spectrometer and the light output efficiency of the fluorescence probe input into the spectrometer. The specific scope of protection shall be determined by the claims, and this application does not impose any special limitations thereon.

[0099] FIG9 is a schematic diagram of the structure of an optical fiber probe in another three-dimensional fluorescence detection device provided by an embodiment of the present application. FIG9 uses a multi-core fluorescent optical fiber probe. When a multi-core optical fiber is used as a fluorescent optical fiber probe, a single-core optical fiber with a small core diameter needs to be selected. By closely arranging m single-core optical fibers with small core diameters, a bundled multi-core optical fiber is formed. The receiving end of the multi-core optical fiber needs to closely arrange m single-core optical fibers with small core diameters to form a circular end face, that is, the receiving end is located in the fluorescence excitation region for receiving the fluorescence signal generated by stimulated radiation; in order to ensure the reception efficiency of the fluorescence signal, it is necessary to select a suitable single-core optical fiber with a small core diameter and a suitable optical fiber bundle size m so that the diameter of the circular receiving end face formed by the close arrangement is on the order of several millimeters. As a non-limiting embodiment, in the present application, the diameter of the small-core single-core optical fiber used is 50um, and the diameter of the end face of the receiving end formed by the close arrangement is about 3mm. The optical fiber probe interface of the spectrometer used in this embodiment is an input slit, so the output end of the multi-core optical fiber in this embodiment is linearly arranged according to the slit.

[0100] In one embodiment, optionally, since the probe interface of the spectrometer includes various shapes such as circular and slit, in order to ensure the propagation efficiency of light, the output end of the multi-core optical fiber can be arranged according to the shape of the input interface of the spectrometer. Alternatively, the output end of the optical fiber can be optically designed in combination with the shape of the probe interface of the spectrometer to ensure the signal quality of the fluorescence signal received by the spectrometer and the light output efficiency of the fluorescence probe input into the spectrometer. The specific scope of protection shall be based on the claims, and this application does not specifically limit this.

[0101] In this application, the time-sharing drive of the array light source is achieved by sending a time-sharing pulse drive signal from the control and data processing module. By time-sharing the LED array light source to emit a single wavelength of excitation light, the fluorescence detection device and the light intensity detection device synchronously and time-sharingly receive the detected fluorescence signal and transmitted light signal, thereby generating fluorescence spectrum data and transmitted light intensity data. The control and data processing module then processes the data based on the correspondence between the fluorescence spectrum data and the transmitted light intensity data and the excitation light wavelength, thereby obtaining a three-dimensional fluorescence spectrum and absorption spectrum of the sample. The following will describe the drive signal sent by the control and data processing module and the data processing process in conjunction with Figures 10 to 12.

[0102] FIG10 is a schematic diagram of the array light source drive signal in a three-dimensional fluorescence detection device provided in an embodiment of the present application. The control and data processing module sends an LED time-sharing pulse drive signal to the LED array light source. This drive signal drives the constant current source to provide current pulse drive to LED1, LED2, LED3, etc. in a time-sharing manner. As a non-limiting embodiment, the current pulse signal for each LED in the present application is driven by a square wave, with a pulse duration of 500ms. That is, each LED light source is illuminated for 500ms in a time-sharing manner under the action of the pulse signal. The fluorescence signal generated by the stimulated radiation of the sample in the fluorescence excitation region can also be approximately considered to be a square wave pulse fluorescence signal lasting 500ms.

[0103] When the control and data processing module sends a time-sharing pulse drive signal to the array light source, it also synchronously sends a synchronization trigger signal to the trigger interface of the spectrometer. After receiving the synchronization trigger signal, the spectrometer activates the detector within the spectrometer to begin measurement. The measured integration time is used as a reference to obtain a good fluorescence signal-to-noise ratio and can be set to an appropriate integration time window that is less than the duration of the excitation light pulse. As a non-limiting example, the integration time window in this application can be set within the range of 400ms-480ms based on the detected fluorescence signal-to-noise ratio. The specific value can be set based on the measured fluorescence signal-to-noise ratio as a reference.

[0104] When the control and data processing module sends a time-sharing LED pulse drive signal to the array light source, that is, the control and data processing module sequentially drives each LED light source to emit excitation light with a 500ms pulse current, the spectrometer also synchronously measures the fluorescence spectrum corresponding to each LED, that is, each wavelength of excitation light. As a non-limiting example, this application uses surface water as a sample and detects the surface water to obtain a three-dimensional fluorescence spectrum and absorption spectrum. The following, combined with Figures 11 and 12, explains how to detect the sample to obtain a three-dimensional fluorescence spectrum and absorption spectrum.

[0105] Figure 11 shows a three-dimensional fluorescence spectrum generated by a sample detected using a three-dimensional fluorescence detection device provided in an embodiment of the present application. The figure includes fluorescence spectra excited by excitation light at wavelengths of 250nm, 260nm, and so on, up to 400nm. It should be understood that each wavelength of excitation light corresponds to a single LED light source. Each fluorescence spectrum in the figure is a two-dimensional spectrum line, with the abscissa representing the wavelength of the fluorescence signal and the ordinate representing the intensity of the fluorescence signal. The Gaussian-shaped portion protruding at the front of each fluorescence line in the figure represents the Rayleigh scattering of the excitation light, while the trailing portion after the Rayleigh scattering represents the fluorescence signal of the sample. To output the three-dimensional fluorescence spectrum of the sample, the control and data processing module automatically deducts the Rayleigh scattering component at the front of each fluorescence line, then uses a compensation algorithm to calculate the leading edge of the fluorescence spectrum. The three-dimensional fluorescence spectrum of the sample is then generated, with the wavelength of the array light source excitation light as the X-axis, the wavelength of the fluorescence signal as the Y-axis, and the intensity of the fluorescence signal as the Z-axis. This is shown in the inset diagram in the upper right corner of Figure 11, which is the three-dimensional fluorescence spectrum of surface water.

[0106] As a non-limiting example, the compensation algorithm used in this application includes an interpolation algorithm. Other compensation algorithms may also be used based on the characteristics of the sampled data, which are not listed here. The specific scope of protection shall be based on the claims, and this application does not specifically limit this.

[0107] For transmissive samples, the present application can also simultaneously obtain the sample's absorption spectrum, such as the surface water mentioned above. It should be understood that the detection samples of the present application can include both transmissive samples and non-transmissive samples, and valuable absorption spectra can be generated for transmissive samples simultaneously; for non-transmissive samples, this means that the excitation light beam is completely absorbed and / or reflected by the non-transmissive sample, and the absorption spectrum obtained is meaningless.

[0108] Figure 12 is an absorption spectrum generated by detecting a sample using a three-dimensional fluorescence detection device provided in an embodiment of the present application. The excitation light emitted by the LED array light source penetrates the sample area and reaches the absorption target surface of the light intensity detection device, that is, the photodetector PIN target surface in the embodiment of the present application. After the photodetector receives the pulsed square wave light signal of 500ms emitted by each LED light source, it passes through the TIA amplification circuit and AD analog-to-digital conversion to a digital signal and transmits it to the control and data processing module. The control and data processing module averages the received transmitted light intensity data within the set time integration window to obtain the transmitted light intensity value. As a non-limiting embodiment, in order to obtain the absorption spectrum of the sample in this application, it is necessary to scan the LED array light source in the absence of a sample to obtain the initial light intensity value I0 of the excitation light emitted by each light source, and then place the sample to be tested in the sample area, scan the LED array light source again, and obtain the light intensity value I1 of the transmitted light after penetrating the sample. According to the Beer-Lambert law, the formula for calculating the sample absorbance is:

[0109] Where abs represents the absorbance of the sample. Formula (2) allows the absorption spectrum of the sample to be determined based on the measured initial light intensity value I0 and the transmitted light intensity value I1. The absorption spectrum of the surface water sample in this application is shown in Figure 12, where the abscissa represents the wavelength of the excitation light emitted by the array light source, and the ordinate corresponds to the abs absorbance value of the excitation light at each wavelength.

[0110] It should be understood that since the wavelength interval of the excitation light emitted by each LED in the array light source is 10nm to 20nm, the absorption spectrum measured by the above method is plotted as discrete points spaced 10nm to 20nm apart. The resolution of the absorption spectrum is determined by the wavelength interval of each single-wavelength light source in the array light source. For most mixture samples, the absorption spectrum of the sample exhibits a broad and smooth spectrum. The continuous absorption spectrum curve obtained by interpolating and smoothing the absorption spectrum data composed of N discrete points obtained in this application is consistent with the absorption spectrum obtained under the same conditions using high-precision laboratory absorption spectrum measurement equipment.

[0111] It should be noted that Figures 1 to 12 are merely schematic illustrations for facilitating understanding of the embodiments of the present application and do not constitute a particular limitation on the present application.

[0112] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A three-dimensional fluorescence detection device, characterized in that: include: A monochromatic array light source, a first lens group, a fluorescence detection device, a light intensity detection device, a control and data processing module, wherein: The monochromatic array light source is used to emit excitation light, and the monochromatic array light source includes N monochromatic light sources, and the monochromatic light source is used to emit light with a single wavelength, and the excitation light includes light of N wavelengths and covers a first band, wherein N is a positive integer greater than or equal to 2, and the first band has an intersection with a fluorescence excitation band of a sample to be tested; The first lens group is used to receive the excitation light and converge and overlap the excitation light to form an excitation area, wherein N beams of the excitation light are incident on the first lens group at different positions, and the sample to be tested is placed in the excitation area; The fluorescence detection device is used to receive the fluorescence signal generated by the sample to be tested and output fluorescence spectrum data. The light intensity detection device is used to receive the excitation light transmitted from the sample to be tested and output the transmitted light intensity data; The control and data processing module is used to control the monochromatic array light source to emit the excitation light, and is also used to receive the fluorescence spectrum data and the transmitted light intensity data to determine the three-dimensional fluorescence spectrum and absorption spectrum of the sample to be tested.

2. The three-dimensional fluorescence detection device according to claim 1, characterized in that: The N wavelengths of light emitted by the N monochromatic light sources are sequentially spaced apart by a first wavelength, including: When N is greater than or equal to 3, the nth monochromatic light source emits light having a first wavelength, the n+1th monochromatic light source emits light having a second wavelength, and the n+2th monochromatic light source emits light having a third wavelength, and n, n+1, and n+2 are positive integers belonging to N; The first wavelength and the second wavelength differ by a first value, the second wavelength and the third wavelength differ by a second value, and the first wavelength interval includes the first value and the second value.

3. The three-dimensional fluorescence detection device according to claim 1 or 2, characterized in that: The lights emitted by the N monochromatic light sources are directly coupled through N optical fibers respectively. The N optical fibers transmit the excitation light emitted by the monochromatic array light source to the first lens group. The output ends of the N optical fibers are arranged in a nonlinear manner.

4. The three-dimensional fluorescence detection device according to claim 1 or 2, characterized in that: The lights emitted by the N monochromatic light sources are coupled into N optical fibers through N coupling lenses respectively. The N optical fibers transmit the excitation light emitted by the monochromatic array light source to the first lens group. The output ends of the N optical fibers are arranged nonlinearly.

5. The three-dimensional fluorescence detection device according to claim 3 or 4, characterized in that: The nonlinear arrangement includes a closely packed arrangement, wherein the closely packed arrangement includes a minimum surface area of ​​an output end cross section formed by the arrangement of the N optical fibers, and the output end cross section includes a circle.

6. The three-dimensional fluorescence detection device according to any one of claims 1 to 5, characterized in that: Also includes: The second lens group is used to converge the excitation light transmitted from the sample to be tested to the receiving target surface of the light intensity detection device, and the diameter of the light spot formed by the convergence of the excitation light is less than or equal to the diameter of the photosensitive area of ​​the receiving target surface.

7. The three-dimensional fluorescence detection device according to any one of claims 1 to 6, characterized in that: The control and data processing module is used to control the monochromatic array light source to emit the excitation light, including: The control and data processing module sends a driving signal to the monochromatic array light source, wherein the driving signal includes a square wave pulse signal, and the driving signal is used to sequentially drive N monochromatic light sources to emit light in sequence, and the light emission duration of the monochromatic light source is the pulse duration of the square wave pulse signal.

8. The three-dimensional fluorescence detection device according to claim 7, characterized in that: The control and data processing module is also used to send a synchronization trigger instruction to the fluorescence detection device to start the fluorescence detection device to sequentially receive the pulse fluorescence signals generated by the excitation area.

9. The three-dimensional fluorescence detection device according to any one of claims 1 to 8, characterized in that: The fluorescence detection device includes an optical fiber probe and a spectrometer. The optical fiber probe is used to obtain the fluorescence signal generated by the excitation region. The spectrometer is used to obtain the composition of the fluorescence bands in the fluorescence signal and the light intensity of the fluorescence in each band.

10. The three-dimensional fluorescence detection device according to claim 9, characterized in that: The optical fiber probe comprises a single-core fluorescent optical fiber probe, The input end of the single-core fluorescent optical fiber probe directly detects the fluorescent signal generated by the excitation region. The output end of the single-core fluorescent optical fiber probe is directly connected to the optical fiber probe interface of the spectrometer.

11. The three-dimensional fluorescence detection device according to claim 9, characterized in that: The optical fiber probe comprises a multi-core fluorescent optical fiber probe, The multi-core fluorescent optical fiber probe comprises three or more single-core optical fibers, and the single-core optical fibers are arranged in a closely spaced manner. The rows are arranged to form the input end of the multi-core fluorescent probe, and the input end is used to detect the fluorescent signal generated by the excitation area; The single-core optical fiber is arranged in a linear manner to form the output end of the multi-core fluorescent probe, and the output end is connected to the optical fiber probe interface of the spectrometer.

12. The three-dimensional fluorescence detection device according to any one of claims 9 to 11, characterized in that: The detection distance between the input end of the optical fiber probe and the excitation region includes: 2×d×NA=D Wherein, d is the detection distance, NA is the numerical aperture of the optical fiber probe, and D is the diameter of the light spot formed by the excitation light converging in the excitation region.

13. The three-dimensional fluorescence detection device according to any one of claims 1 to 12, characterized in that: The light intensity detection device includes a photodetector and an amplifier circuit. The photodetector is used to receive the excitation light transmitted from the sample to be tested, and convert the received light signal into an electrical signal; The amplifier circuit is used to amplify the electrical signal.

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