A microfluidic chip type radioactivity spectrum detection system and a detection method

Abstract

The application provides a microfluidic chip type radioactivity energy spectrum detection system, wherein a photoelectric conversion module, an amplification circuit module, an AD sampling module, a signal processing module, a signal transmission module and a host computer terminal are sequentially connected in signal; an upper layer chip of a microfluidic chip is arranged on a lower layer chip; an outer peripheral side surface of the upper layer chip is respectively provided with an inlet and outlet sample port; a detection pool is arranged in the upper layer chip; the inlet and outlet sample ports are respectively connected in pipeline communication; and a radioactive liquid sample inlet module is connected in pipeline communication with the inlet sample port; the photoelectric conversion module is embedded in the middle of the bottom of the lower layer chip; a solid scintillator is embedded in the lower layer chip and located between the detection pool and the photoelectric conversion module and is attached to the photoelectric conversion module; and a vertical annular shielding shell is embedded in the lower layer chip and is sleeved outside the solid scintillator. A related detection method is also provided. The energy spectrum detection system can realize energy spectrum detection of trace radioisotopes, the working voltage is reduced to tens of volts, thereby reducing the detection cost and improving the portability and safety.

Description

Technical Field

[0001] This invention relates to the field of nuclear radiation detection technology, and particularly to the field of radioactive energy spectrum detection technology, specifically a microfluidic chip-based radioactive energy spectrum detection system and detection method. Background Technology

[0002] Nuclear radiation detection refers to the detection of the presence, intensity, type (such as mass number A, charge number Z, etc.), energy, and emission angular distribution of nuclear radiation using a nuclear radiation detector. Nuclear radiation detection is crucial in both basic research and practical applications. It is a tool for understanding the microscopic world, atoms, atomic nuclei, and even deeper microscopic phenomena. In practical applications, nuclear radiation detection is the foundation and an important component of various nuclear technologies and radiation protection technologies. The interaction between radiation and matter is the physical basis of nuclear radiation detection.

[0003] Currently, there are several mature detection methods in the field of nuclear radiation detection, such as liquid scintillation counting and solid scintillation detection.

[0004] For example, Chinese invention patent application (publication number CN120949289A) discloses a tritium detector and a double-layer scintillator detector array. This tritium detector mainly consists of the following key components: an outer scintillator, an inner scintillator, and a photodetector. The outer scintillator surrounds the inner scintillator and its main function is to detect beta rays; the inner scintillator is used to detect gamma rays in the environment; the photodetector is optically coupled to both the inner and outer scintillators to receive the light signals generated by the scintillators. With this structure, the device can achieve efficient measurement of tritium beta signals while effectively suppressing interference from ambient gamma rays.

[0005] Chinese invention patent application (publication number CN120522756A) discloses a scintillator detection device based on a photomultiplier tube. This device mainly consists of an electromagnetic shielding shell, a scintillator crystal, a photomultiplier tube, and back-end electronic components. The scintillator crystal is installed inside the electromagnetic shielding shell to detect radiation from the outside. The photomultiplier tube is installed inside the electromagnetic shielding shell on the side closer to the scintillator crystal to convert the light signal generated by the scintillator crystal into an electrical signal. The back-end electronic components are installed inside the electromagnetic shielding shell on the side of the photomultiplier tube away from the scintillator crystal and are electrically connected to the photomultiplier tube. To meet detection requirements, a beryllium window is provided on the end face of the scintillator crystal on the side away from the photomultiplier tube.

[0006] However, existing nuclear radiation detection devices have the following main problems: First, because liquid scintillator counters and traditional solid scintillator detectors are too heavy and bulky, they cannot be portable or lightweight for routine detection of radioactive liquids. Moreover, they rely heavily on physical shielding with heavy metals, which affects the portability of routine detection.

[0007] Secondly, liquid scintillation counters consume large quantities of samples and generate a significant amount of radioactive chemical waste that is difficult to dispose of safely, posing a high risk of contamination. Furthermore, their macroscopic and lagging measurement methods are no longer sufficient to meet the demands of modern high-frequency, real-time continuous detection of trace radioactive samples.

[0008] Furthermore, photomultiplier tubes require a power supply voltage as high as 800V to 2000V. This extremely high operating voltage not only requires a bulky, high-heat-generating high-voltage module and heavy-duty insulated shielded cables, but also poses a high risk of breakdown leakage and safety hazards in daily detection and experimental analysis scenarios.

[0009] Therefore, it is desirable to provide a radioactive energy spectrum detection system that can realize the energy spectrum detection of radioactive isotopes, reduce the detection volume to the microliter or even nanoliter level, reduce the operating voltage to the tens of volts level, achieve safe detection, save raw materials and consumables, and miniaturize the size of the energy spectrum detector, thereby reducing detection costs and improving portability and safety. Summary of the Invention

[0010] In order to overcome the shortcomings of the prior art, one object of the present invention is to provide a microfluidic chip-based radioactive energy spectrum detection system, which can realize the energy spectrum detection of radioactive isotopes and reduce the detection volume to the microliter or even nanoliter level, and reduce the operating voltage to the tens of volts level, thereby achieving safe detection, saving raw materials and consumables, and miniaturizing the size of the energy spectrum detector, thereby reducing detection costs, improving portability and safety, and making it suitable for large-scale promotion and application.

[0011] Another objective of this invention is to provide a microfluidic chip-based radiometric energy spectrum detection method, which can realize the energy spectrum detection of radioactive isotopes and reduce the detection volume to the microliter or even nanoliter level, and reduce the operating voltage to the tens of volts level, thereby achieving detection safety and saving raw material consumables, thereby reducing detection costs, improving safety, and being suitable for large-scale promotion and application.

[0012] To achieve the above objectives, in a first aspect of the present invention, a microfluidic chip-based radioactive energy spectrum detection system is provided, comprising a radioactive liquid sample introduction module, a solid scintillator, a photoelectric conversion module, an amplification circuit module, a power supply module, an AD sampling module, a signal processing module, a signal transmission module, and a host computer terminal. The photoelectric conversion module, the amplification circuit module, the AD sampling module, the signal processing module, the signal transmission module, and the host computer terminal are sequentially connected by signals. The power supply module is electrically connected to both the photoelectric conversion module and the amplification circuit module. The system is characterized in that the microfluidic chip-based radioactive energy spectrum detection system further includes a microfluidic chip and a vertical annular shielding shell, wherein: The microfluidic chip includes an upper chip and a lower chip, both of which are horizontally arranged and aligned in the left-right direction. The upper chip is disposed on the lower chip, and an inlet and an outlet are respectively provided on the outer peripheral side of the upper chip. A detection cell is disposed inside the upper chip, located between the inlet and the outlet and connected to the inlet and outlet by pipelines. The radioactive liquid injection module is connected to the inlet by pipelines to deliver the radioactive liquid to be detected into the inlet. The photoelectric conversion module is horizontally arranged along the left-right direction. The photoelectric conversion module is located below the bottom of the lower chip and embedded in the bottom of the lower chip. The solid scintillator is horizontally arranged along the left-right direction. The solid scintillator is embedded in the lower chip and located between the detection cell and the photoelectric conversion module and attached to the photoelectric conversion module. The vertical annular shielding shell is embedded in the lower chip and sleeved on the solid scintillator.

[0013] Preferably, the upper-layer chip is bonded to the lower-layer chip.

[0014] Preferably, both the upper-layer chip and the lower-layer chip are rectangular.

[0015] Preferably, the inlet and outlet are spaced apart from each other.

[0016] Preferably, the detection cell is located at the center of the bottom of the upper chip.

[0017] Preferably, the detection pool is planar spiral-shaped.

[0018] Preferably, the vertical annular shielding shell is a metal shielding shell.

[0019] Preferably, the solid-state scintillator is cuboid in shape, the vertical annular shielding shell is a vertical rectangular annular shielding shell, and the photoelectric conversion module is rectangular.

[0020] Preferably, the bottom of the lower chip is vertically provided with a groove, the groove is located below the detection cell, the photoelectric conversion module is located below the groove opening and embedded in the groove opening, the solid scintillator is embedded in the groove, and the vertical annular shielding shell is embedded in the groove.

[0021] In a second aspect of the present invention, a microfluidic chip-based radiometric energy dispersive spectroscopy detection method is provided, characterized by employing the aforementioned microfluidic chip-based radiometric energy dispersive spectroscopy detection system and comprising the following steps: (1) The radioactive liquid to be tested is delivered to the inlet through the radioactive liquid injection module, and then the radioactive liquid to be tested flows through the detection pool and flows out through the outlet; (2) During the process of the radioactive liquid to be detected flowing through the detection cell, the solid scintillator converts the γ-rays emitted by the radioactive liquid to be detected into light signals; (3) The power supply module supplies power to the photoelectric conversion module and the amplifier circuit module respectively; (4) The photoelectric conversion module captures the optical signal and converts the optical signal into a voltage signal, and then sends the voltage signal to the amplification circuit module; (5) The amplifier circuit module receives the voltage signal and converts the voltage signal into a pulse signal, and then sends the pulse signal to the AD sampling module; (6) The AD sampling module receives the pulse signal and converts the pulse signal into a digital signal, and then sends the digital signal to the signal processing module; (7) The signal processing module receives the digital signal and performs digitization processing on the digital signal to obtain a digitized signal, and then sends the digitized signal to the host computer terminal. (8) The host computer terminal receives the digitized signal and performs energy spectrum reconstruction and analysis based on the digitized signal to realize the identification of radioactive isotope types and the display of energy spectrum output.

[0022] The main beneficial effects of this invention are: 1. In the microfluidic chip-based radiometric energy spectrum detection system of the present invention, the photoelectric conversion module, amplification circuit module, AD sampling module, signal processing module, signal transmission module, and host computer terminal are sequentially connected by signals. The power supply module is electrically connected to the photoelectric conversion module and the amplification circuit module respectively. The microfluidic chip includes an upper chip and a lower chip, both of which are horizontally arranged and aligned along the left-right direction. The upper chip is disposed on the lower chip. An inlet and an outlet are respectively provided on the outer peripheral side of the upper chip. A detection cell is provided inside the upper chip, located between the inlet and the outlet, and connected to the inlet and outlet by pipelines respectively. The radiometric liquid injection module is connected to the inlet by pipelines to deliver the radiometric liquid to be detected to the inlet. The photoelectric conversion module is horizontally positioned along the left-right direction, located at the bottom of the lower chip and embedded within it. The solid-state scintillator is horizontally positioned along the left-right direction, embedded in the lower chip and located between the detection cell and the photoelectric conversion module, and attached to the photoelectric conversion module. The vertical annular shielding shell is embedded in the lower chip and sleeved on the solid-state scintillator. Therefore, it can realize the energy spectrum detection of radioactive isotopes, and reduce the detection volume to the microliter or even nanoliter level, and reduce the operating voltage to the tens of volts level, achieving safe detection, saving raw materials and consumables, and miniaturizing the size of the energy spectrum detector, thereby reducing detection costs, improving portability and safety, and making it suitable for large-scale promotion and application.

[0023] 2. The microfluidic chip-type radioactive energy spectrum detection method of the present invention is performed using the above-mentioned microfluidic chip-type radioactive energy spectrum detection system and includes the following steps: (1) The radioactive liquid to be detected is transported to the inlet through the radioactive liquid injection module, and then the radioactive liquid to be detected flows through the detection cell and flows out through the outlet; (2) During the process of the radioactive liquid to be detected flowing through the detection cell, the solid scintillator converts the γ-rays emitted by the radioactive liquid to be detected into light signals; (3) The power supply module supplies power to the photoelectric conversion module and the amplification circuit module respectively; (4) The photoelectric conversion module captures the light signal and converts the light signal into a voltage signal, and then sends the voltage signal to the amplification circuit module; (5) The amplification circuit module receives the voltage signal and converts the voltage signal into a pulse signal, and then sends the pulse signal to the AD sampling module; 6) The AD sampling module receives the pulse signal and converts the pulse signal into a digital signal, and then sends the digital signal to the signal processing module; (7) The signal processing module receives the digital signal and performs digital processing on the digital signal to obtain the digitally processed signal, and then sends the digitally processed signal to the host computer terminal; (8) The host computer terminal receives the digitally processed signal and performs energy spectrum reconstruction and analysis based on the digitally processed signal to realize the identification of radioactive isotope types and the display of energy spectrum output. Therefore, it can realize the energy spectrum detection of radioactive isotopes and reduce the detection volume to microliters or even nanoliters, and reduce the working voltage to tens of volts, so as to realize the safety of detection and the saving of raw materials and consumables, thereby reducing the detection cost and improving safety, and is suitable for large-scale promotion and application.

[0024] These and other objects, features and advantages of the present invention will be fully apparent from the following detailed description and drawings, and can be achieved by the means, devices and combinations thereof specifically pointed out in the summary of the invention. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a specific embodiment of the microfluidic chip-based radiometric energy spectrum detection system of the present invention.

[0026] Figure 2 yes Figure 1 The schematic diagram shows a front cross-sectional view of the components of the microfluidic chip, the vertical annular shielding shell, the solid scintillator, and the photoelectric conversion module in the specific embodiment shown.

[0027] Figure 3 yes Figure 1 The exploded perspective view of the components of the microfluidic chip, vertical annular shielding shell, solid scintillator, and photoelectric conversion module in the specific embodiment shown.

[0028] Figure 4 yes Figure 1 A three-dimensional perspective view of the upper layer chip of the microfluidic chip in the specific embodiment shown.

[0029] Figure 5 This is the energy dispersive spectroscopy (EDS) output diagram of the NaI-131 solution detected in Example 1.

[0030] Figure 6 This is the energy dispersive spectroscopy (EDS) output of the NaI-131 solution detected in Comparative Example 1.

[0031] Figure 7 This is the energy dispersive spectroscopy (EDS) output diagram of the F-18 labeled deoxyglucose solution detected in Example 2.

[0032] Figure 8 This is the energy dispersive spectroscopy output of the F-18 labeled deoxyglucose solution detected in Comparative Example 2.

[0033] (Explanation of reference numerals in the attached image) 1. Solid-state scintillator; 2. Photoelectric conversion module; 3 Microfluidic chip; 31 Upper chip; 311 Sample inlet; 312 Sample outlet; 313 Detection cell; 32 Lower chip; 321 Groove; 4. Vertical annular shielding shell. Detailed Implementation

[0034] To enable the detection of energy spectrum of trace amounts of radioactive liquids at a lower operating voltage, achieving safe detection, saving on raw materials and consumables, and miniaturizing the detector size, thereby reducing detection costs and improving the portability and safety of the energy spectrum detection device, the inventors, through in-depth research, discovered that by developing a microfluidic chip, the radioactive liquid to be detected is delivered to the microfluidic chip through a radioactive liquid injection module. The radioactive liquid flows through the microfluidic chip, and a solid scintillator converts the gamma rays of the radioactive liquid into an optical signal. A photoelectric conversion module converts the optical signal into a voltage signal, and an amplification circuit module converts the voltage signal into a pulse signal. The pulse signal is then subjected to a series of subsequent processing steps to finally obtain the energy spectrum of the radioactive liquid to be detected. Based on this, the present invention was completed.

[0035] This invention first provides a microfluidic chip-based radiometric energy dispersive spectroscopy detection system, please refer to [link to relevant documentation]. Figures 1-4As shown, in a specific embodiment of the microfluidic chip-based radioactive energy spectrum detection system of the present invention, it includes a radioactive liquid injection module, a solid scintillator 1, a photoelectric conversion module 2, an amplification circuit module, a power supply module, an AD sampling module, a signal processing module, a signal transmission module, and a host computer terminal. The photoelectric conversion module 2, the amplification circuit module, the AD sampling module, the signal processing module, the signal transmission module, and the host computer terminal are sequentially connected by signals. The power supply module is electrically connected to the photoelectric conversion module 2 and the amplification circuit module respectively. The microfluidic chip-based radioactive energy spectrum detection system also includes a microfluidic chip 3 and a vertical annular shielding shell 4, wherein: The microfluidic chip 3 includes an upper chip 31 and a lower chip 32. Both the upper chip 31 and the lower chip 32 are horizontally arranged and arranged along the left-right direction. The upper chip 31 is disposed on the lower chip 32. The outer peripheral side of the upper chip 31 is respectively provided with an inlet 311 and an outlet 312. A detection cell 313 is disposed inside the upper chip 31. The detection cell 313 is located between the inlet 311 and the outlet 312 and is respectively connected to the inlet 311 and the outlet 312 by pipelines. The radioactive liquid injection module is connected to the inlet 311 by pipelines to deliver the radioactive liquid to be detected to the inlet 311. The photoelectric conversion module 2 is horizontally arranged along the left-right direction. The photoelectric conversion module 2 is located below the bottom of the lower chip 32 and embedded in the bottom of the lower chip 32. The solid scintillator 1 is horizontally arranged along the left-right direction. The solid scintillator 1 is embedded in the lower chip 32 and located between the detection cell 313 and the photoelectric conversion module 2 and is attached to the photoelectric conversion module 2. The vertical annular shielding shell 4 is embedded in the lower chip 32 and sleeved on the outside of the solid scintillator 1.

[0036] The upper chip 31 is disposed on the lower chip 32 and can adopt any suitable structure. In a specific embodiment of the present invention, the upper chip 31 is bonded to the lower chip 32, and the upper chip 31 and the lower chip 32 are bonded to each other through a bonding process to achieve high-strength bonding.

[0037] The upper-layer chip 31 and the lower-layer chip 32 can have any suitable shape. Please refer to [link / reference]. Figures 3-4 As shown, in a specific embodiment of the present invention, both the upper chip 31 and the lower chip 32 are rectangular.

[0038] The inlet 311 and the outlet 312 can have any suitable relative position. Please refer to [link / reference]. Figure 2 and Figure 4As shown, in a specific embodiment of the present invention, the sample inlet 311 and the sample outlet 312 are arranged at intervals from each other.

[0039] The detection cell 313 is disposed within the upper-layer chip 31 and can be placed at any suitable location within the upper-layer chip 31. (See [link to relevant documentation]). Figures 2-4 As shown, in a specific embodiment of the present invention, the detection cell 313 is disposed at the center of the bottom of the upper chip 31.

[0040] The detection cell 313 can have any suitable shape; please refer to [link / reference]. Figure 4 As shown, in a specific embodiment of the present invention, the detection pool 313 is a planar spiral shape, similar to the planar spiral shape of a single mosquito coil.

[0041] The vertical annular shielding shell 4 is used to effectively shield external radiation interference. It can be any suitable material, but preferably, it is a metal shielding shell. In a specific embodiment of the present invention, the metal shielding shell is a copper foil shielding shell, used to intercept high-energy positrons that penetrate the thin wall of the microfluidic chip 3 and filter out stray interference from the kinetic energy of continuous positrons on the energy spectrum.

[0042] The wall thickness of the vertical annular shielding shell 4 can be determined as needed. In a specific embodiment of the present invention, the wall thickness of the vertical annular shielding shell 4 is 0.1 mm.

[0043] The solid scintillator 1 is used to convert γ-rays into optical signals. Generally, inorganic scintillators such as LYSO, CsI(TI) and NaI(TI) are used. Among them, CsI(TI) and NaI(TI) are hygroscopic materials and need to be treated with moisture protection.

[0044] The solid-state scintillator 1, the vertical annular shielding shell 4, and the photoelectric conversion module 2 can have any suitable shape. Please refer to [link / reference needed]. Figure 3 As shown, in a specific embodiment of the present invention, the solid scintillator 1 is cuboid in shape, the vertical annular shielding shell 4 is a vertical rectangular annular shielding shell, and the photoelectric conversion module 2 is rectangular.

[0045] The photoelectric conversion module 2 is embedded in the bottom of the lower-layer chip 32, the solid-state scintillator 1 is embedded in the lower-layer chip 32, and the vertical annular shielding shell 4 is embedded in the lower-layer chip 32. Any suitable structure can be used; please refer to [link / reference]. Figures 2-3As shown, in a specific embodiment of the present invention, the bottom of the lower chip 32 is provided with a groove 321, the groove 321 is located below the detection pool 313, the photoelectric conversion module 2 is located below the groove opening of the groove 321 and is embedded in the groove opening of the groove 321, the solid scintillator 1 is embedded in the groove 321, and the vertical annular shielding shell 4 is embedded in the groove 321. When the solid scintillator 1 is cuboid, the vertical annular shielding shell 4 is a vertical rectangular annular shielding shell, and the photoelectric conversion module 2 is rectangular, the groove 321 is rectangular, for example, with a length of 10.5 mm, a width of 10.5 mm, and a height of 5.5 mm. It can be milled using computer numerical control (CNC) technology to accommodate the vertical annular shielding shell 4 and the solid scintillator 1. The length, width, and height of the solid scintillator 1 can be 10 mm, 10 mm, and 5 mm, respectively. Preferably, it can be polished on all six sides, and the four sides and the top surface can be coated with reflective film or wrapped with white Teflon tape (PTFE) with a thickness of 0.1 mm to control the photons to emit light only from the bottom surface, thereby increasing the amount of light collected and achieving maximum light signal collection.

[0046] The solid scintillator 1 is attached to the photoelectric conversion module 2 and can adopt any suitable structure. In a specific embodiment of the present invention, the solid scintillator 1 is attached to the photoelectric conversion module 2 by means of an optical coupling agent.

[0047] The radioactive liquid injection module can be any suitable device. In one specific embodiment of the present invention, the radioactive liquid injection module is a radioactive liquid injection pump.

[0048] The power supply module is used to provide bias voltage to the photoelectric conversion module 2 and to power the amplifier circuit module.

[0049] The photoelectric conversion module 2 can be selected to use photoelectric detection devices such as silicon photomultiplier tube (SiPM), photodiode (PD), PIN photodiode and avalanche photodiode (APD). The photosensitive area of ​​the device needs to be close to the light-emitting area of ​​the solid scintillator 1 in order to achieve the maximum light collection efficiency. It is used to capture the light signal generated by the solid scintillator 1 excited by radiation rays and convert the light signal output by the solid scintillator 1 into photoelectrons to obtain a voltage signal.

[0050] The amplifier circuit module is used to amplify the voltage signal output by the photoelectric conversion module 2, reduce noise, perform pulse shaping, improve the overall signal-to-noise ratio of the detector, and obtain a pulse signal.

[0051] The AD sampling module can be an ADC analog-to-digital converter, used to receive the pulse signal output by the amplifier circuit module and convert it into a digital waveform sequence (i.e., a digital signal).

[0052] The signal processing module receives the digital signal from the AD sampling module and performs digital processing on the digital signal using digital processing algorithms. This digital processing includes, but is not limited to, the following methods: digital filtering (such as moving average filtering, median filtering, or Savitzky-Golay filtering) to suppress high-frequency noise; baseline restoration and zero-point drift correction; digital pulse shaping algorithms (such as trapezoidal shaping or exponential filtering) to improve the signal-to-noise ratio; pulse amplitude extraction and pile-up rejection; and normalization and time window filtering to improve the statistical stability of the energy spectrum, eliminate some of the quantization errors and white noise caused by the AD sampling module, and obtain a digitally processed signal.

[0053] The signal transmission module is used to transmit the digitized signal to the host computer terminal.

[0054] The host computer terminal is used to realize the energy spectrum reconstruction, analysis and processing of digitized signals and human-computer interaction, including real-time display of energy spectrum data, energy scale calibration, peak identification, nuclide type analysis, counting statistics, historical data storage and detection result export; it is also used to set detection parameters (such as sampling time, threshold and energy calibration parameters), and can realize remote monitoring and data uploading functions.

[0055] The AD sampling module, the signal processing module, and the signal transmission module together form a multi-channel pulse amplitude analysis system.

[0056] The present invention also provides a microfluidic chip-based radiometric energy dispersive spectroscopy detection method, which uses the above-mentioned microfluidic chip-based radiometric energy dispersive spectroscopy detection system and includes the following steps: (1) The radioactive liquid to be tested is delivered to the inlet through the radioactive liquid injection module, and then the radioactive liquid to be tested flows through the detection pool and flows out through the outlet; (2) During the process of the radioactive liquid to be detected flowing through the detection cell, the solid scintillator converts the γ-rays emitted by the radioactive liquid to be detected into light signals; (3) The power supply module supplies power to the photoelectric conversion module and the amplifier circuit module respectively; (4) The photoelectric conversion module captures the optical signal and converts the optical signal into a voltage signal, and then sends the voltage signal to the amplification circuit module; (5) The amplifier circuit module receives the voltage signal and converts the voltage signal into a pulse signal, and then sends the pulse signal to the AD sampling module; (6) The AD sampling module receives the pulse signal and converts the pulse signal into a digital signal, and then sends the digital signal to the signal processing module; (7) The signal processing module receives the digital signal and performs digitization processing on the digital signal to obtain a digitized signal, and then sends the digitized signal to the host computer terminal. (8) The host computer terminal receives the digitized signal and performs energy spectrum reconstruction and analysis based on the digitized signal to realize the identification of radioactive isotope types and the display of energy spectrum output. The above-mentioned energy spectrum reconstruction and analysis process includes: energy calibration conversion of digital pulse amplitude data to construct a count-energy distribution spectrum; smoothing filtering and background subtraction processing of the count-energy distribution spectrum; spectral line broadening correction of the count-energy distribution spectrum based on the multichannel analysis (MCA) algorithm; peak search and Gaussian fitting of the characteristic peaks of the count-energy distribution spectrum to extract the characteristic energy peak positions; and nuclide identification and activity quantification analysis based on the nuclide database preset in the host computer terminal, ultimately realizing the identification of radioactive isotope types and the display of energy spectrum output. The results can also be stored locally and transmitted remotely.

[0057] To better understand the technical content of this invention, the following embodiments are provided for detailed description. In the following embodiments, the microfluidic chip-based radiometric energy dispersive spectroscopy detection system of this invention is used.

[0058] Example 1 (1) 50 μL of the radioactive liquid to be tested - NaI-131 solution (activity concentration 3.7 MBq / mL) is delivered to the inlet of the microfluidic chip through the radioactive liquid injection module (radioactive liquid injection pump) (flow rate: 10 μL / min, transport method: continuous and stable push transport, control accuracy: within ±1%, pressure range: 0.1MPa). Then the radioactive liquid to be tested flows through the detection cell and flows out through the sample outlet. The sample outlet is connected to a closed radioactive waste collection tank through a pipeline. The radioactive liquid to be tested flowing through the detection cell is centrally recycled to reduce the risk of environmental pollution and meet the requirements of radiation safety regulations.

[0059] (2) During the process of the radioactive liquid to be detected flowing through the detection cell, the solid scintillator converts the γ-rays emitted by the radioactive liquid to be detected into light signals. The sampling time is 200s and the energy range of the energy spectrum acquisition is 100keV. (3) The power supply module provides bias voltage (35V) to the photoelectric conversion module (using silicon photomultiplier tube) and power to the amplifier circuit module; (4) The photoelectric conversion module captures the optical signal and converts it into a voltage signal, and then sends the voltage signal to the amplifier circuit module; (5) The amplifier circuit module receives the voltage signal and converts the voltage signal into a pulse signal, and then sends the pulse signal to the AD sampling module; (6) The AD sampling module receives the pulse signal and converts the pulse signal into a digital signal. The sampling rate is 200 MS / s. Then the digital signal is sent to the signal processing module. (7) The signal processing module receives the digital signal and performs digital processing on the digital signal (performs digital filtering (moving average filtering), baseline restoration and zero drift correction, adopts digital pulse shaping algorithm (trapezoidal shaping), performs pulse amplitude extraction and destacking; performs normalization and time window filtering), obtains the digitally processed signal, and then sends the digitally processed signal to the host computer terminal (specifically, a computer). (8) The host computer terminal receives the digitized signal and performs energy spectrum reconstruction and analysis based on the digitized signal, including: energy calibration conversion of digital pulse amplitude data to construct a count-energy distribution spectrum; smoothing filtering and background subtraction processing of the count-energy distribution spectrum; spectral line broadening correction of the count-energy distribution spectrum based on the multichannel analysis (MCA) algorithm, with 1024 channels; peak search and Gaussian fitting of the characteristic peaks of the count-energy distribution spectrum to extract characteristic energy peak positions; and nuclide identification and activity quantification analysis based on the nuclide database preset in the host computer terminal, ultimately realizing the identification of radioactive isotope types and the display of energy spectrum output. The results are shown in [link to results]. Figure 5 As shown.

[0060] Comparative Example 1 A standard gamma-ray spectrometer (GRAS) using a conventional photomultiplier tube (PMT) coupled to a NaI(Tl) scintillator (a conventional scintillation detector consisting of a NaI(Tl) scintillator and a PMT, manufactured by Shanghai Shuojie Crystal Materials Co., Ltd.) was used to detect the same radioactive sample as in Example 1. Specific conditions were as follows: radioactive sample volume was 10 mL; PMT operating voltage was 600 V; NaI-131 solution was placed in a glass sample vial, which was then placed in front of the detection window of the conventional NaI(Tl) / PMT gamma-ray spectrometer, ensuring close contact between the detector crystal and the bottom of the vial for gamma-ray spectrum measurement; a standard multichannel analyzer (MCA) was used for spectrum acquisition, with 1024 channels; the acquisition time was the same as in Example 1. Results can be found in [link to Example 1]. Figure 6 As shown. By comparing the detection results with those of Example 1, the energy resolution, signal-to-noise ratio, and peak position deviation are basically the same, verifying the detection accuracy and stability of the present invention.

[0061] Example 2 (1) Add 100 μL of the radioactive liquid to be tested - F-18 labeled deoxyglucose solution (¹) 8 F-FDG (activity concentration 7.4 MBq / mL) is delivered to the inlet of the microfluidic chip through the radioactive liquid injection module (radioactive liquid injection pump) (flow rate: 100 μL / min, transport method: continuous and stable push delivery, control accuracy: within ±1%, pressure range: 0.5 MPa). The radioactive liquid to be tested then flows through the detection cell and exits through the sample outlet. The sample outlet is connected to a closed radioactive waste collection tank through a pipeline to centrally recover the radioactive liquid to be tested that has flowed through the detection cell, thereby reducing the risk of environmental pollution and meeting the requirements of radiation safety regulations.

[0062] (2) During the process of the radioactive liquid to be detected flowing through the detection cell, the solid scintillator converts the γ-rays emitted by the radioactive liquid to be detected into light signals. The sampling time is 100s and the energy range of the energy spectrum acquisition is 200keV. (3) The power supply module provides bias voltage (35V) to the photoelectric conversion module (using silicon photomultiplier tube) and power to the amplifier circuit module; (4) The photoelectric conversion module captures the optical signal and converts it into a voltage signal, and then sends the voltage signal to the amplifier circuit module; (5) The amplifier circuit module receives the voltage signal and converts the voltage signal into a pulse signal, and then sends the pulse signal to the AD sampling module; (6) The AD sampling module receives the pulse signal and converts the pulse signal into a digital signal. The sampling rate is 100 MS / s. Then the digital signal is sent to the signal processing module. (7) The signal processing module receives the digital signal and performs digital processing on the digital signal (performs digital filtering (moving average filtering), baseline restoration and zero drift correction, adopts digital pulse shaping algorithm (trapezoidal shaping), performs pulse amplitude extraction and destacking; performs normalization and time window filtering), obtains the digitally processed signal, and then sends the digitally processed signal to the host computer terminal (specifically, a computer). (8) The host computer terminal receives the digitized signal and performs energy spectrum reconstruction and analysis based on the digitized signal, including: energy calibration conversion of digital pulse amplitude data to construct a count-energy distribution spectrum; smoothing filtering and background subtraction processing of the count-energy distribution spectrum; spectral line broadening correction of the count-energy distribution spectrum based on the multichannel analysis (MCA) algorithm, with 2048 channels; peak search and Gaussian fitting of the characteristic peaks of the count-energy distribution spectrum to extract characteristic energy peak positions; and nuclide identification and activity quantification analysis based on the nuclide database preset in the host computer terminal, ultimately realizing the identification of radioactive isotope types and the display of energy spectrum output. The results are shown in [link to results]. Figure 7 As shown.

[0063] Comparative Example 2 A standard gamma-ray spectrometer (using a conventional scintillation detector composed of a NaI(Tl) scintillator coupled with a photomultiplier tube (PMT) and a NaI(Tl) scintillator (model ENAI-D25H25 / 1T01 manufactured by Shanghai Shuojie Crystal Materials Co., Ltd.) was used to detect the same radioactive sample as in Example 2. Specific conditions were as follows: radioactive sample volume was 5 mL; photomultiplier tube operating voltage was 800 V; (F-18 labeled deoxyglucose solution was placed in a glass sample vial, which was placed in front of the detection window of the conventional NaI(Tl) / PMT gamma-ray spectrometer, ensuring close contact between the detector crystal end face and the bottom of the sample vial for gamma-ray spectrum measurement; a standard multichannel analyzer (MCA) was used for spectrum acquisition, with 2048 channels; the acquisition time was the same as in Example 2; results can be found in [link to Example 2]. Figure 8 As shown. By comparing the detection results with those of Example 2, the energy resolution, signal-to-noise ratio, and peak position deviation are basically the same, verifying the detection accuracy and stability of the present invention.

[0064] Therefore, this invention discloses a microfluidic chip-based radioactive energy spectrum detection system, which combines a microfluidic chip with a solid scintillator through an embedded method to realize the energy spectrum detection of radioactive isotopes. It adopts a structure of "vertical annular shielding shell + scintillator crystal (solid scintillator)", which utilizes the vertical annular shielding shell to absorb the kinetic energy of positrons, reduce the background noise of the environment, and improve the signal-to-noise ratio of the detector. It adopts a small photodetector design, which reduces the detector's operating voltage, reduces the detector's working volume, and improves the portability and safety of the energy spectrum detection device.

[0065] Compared with the prior art, the present invention has the following beneficial effects: 1) This invention reduces the detection volume to the microliter (μL) or even nanoliter (nL) level through a microfluidic chip architecture, thereby saving raw materials and improving cost-effectiveness.

[0066] 2) This invention can reduce the size of the detector, thereby enabling the use of miniaturized photodetector design. Compared with traditional energy spectrum detection equipment, it realizes the miniaturization of the energy spectrum detector and improves the portability of the equipment.

[0067] 3) The operating voltage of the present invention can be reduced to tens of volts, thereby reducing the operating voltage of the detector and improving the safety of the energy spectrum detection device.

[0068] 4) This invention introduces a structural mechanism of “vertical annular shielding shell + scintillation crystal (solid scintillator)”: by utilizing the vertical annular shielding shell to silently absorb the continuous random kinetic energy of positrons, the dark counting noise and environmental background are suppressed and reduced, thereby improving the signal-to-noise ratio and outputting a pure γ photon energy spectrum.

[0069] In summary, the microfluidic chip-based radioactive energy spectrum detection system of the present invention can realize the energy spectrum detection of radioactive isotopes, and reduce the detection volume to the microliter or even nanoliter level, and reduce the operating voltage to the tens of volts level. This achieves safe detection, saves raw materials and consumables, and miniaturizes the size of the energy spectrum detector, thereby reducing detection costs, improving portability and safety, and making it suitable for large-scale application.

[0070] Therefore, it is evident that the objective of this invention has been fully and effectively achieved. The function and structural principles of this invention have been demonstrated and explained in the embodiments. Any modifications can be made to the implementation methods without departing from these principles. Therefore, this invention includes all modified embodiments based on the spirit and scope of the claims.

Claims

1. A microfluidic chip-based radiometric energy dispersive spectroscopy (RFES) detection system, comprising a radioactive liquid injection module, a solid-state scintillator, a photoelectric conversion module, an amplification circuit module, a power supply module, an analog-to-digital (AD) sampling module, a signal processing module, a signal transmission module, and a host computer terminal, wherein the photoelectric conversion module, the amplification circuit module, the AD sampling module, the signal processing module, the signal transmission module, and the host computer terminal are sequentially signal-connected, and the power supply module is electrically connected to both the photoelectric conversion module and the amplification circuit module, characterized in that... The microfluidic chip-based radiometric energy dispersive spectroscopy detection system further includes a microfluidic chip and a vertical annular shielding shell, wherein: The microfluidic chip includes an upper chip and a lower chip, both of which are horizontally arranged and aligned in the left-right direction. The upper chip is disposed on the lower chip, and an inlet and an outlet are respectively provided on the outer peripheral side of the upper chip. A detection cell is disposed inside the upper chip, located between the inlet and the outlet and connected to the inlet and outlet by pipelines. The radioactive liquid injection module is connected to the inlet by pipelines to deliver the radioactive liquid to be detected into the inlet. The photoelectric conversion module is horizontally arranged along the left-right direction. The photoelectric conversion module is located below the bottom of the lower chip and embedded in the bottom of the lower chip. The solid scintillator is horizontally arranged along the left-right direction. The solid scintillator is embedded in the lower chip and located between the detection cell and the photoelectric conversion module and attached to the photoelectric conversion module. The vertical annular shielding shell is embedded in the lower chip and sleeved on the solid scintillator.

2. The microfluidic chip-based radiometric energy dispersive spectroscopy detection system as described in claim 1, characterized in that, The upper-layer chip is bonded to the lower-layer chip.

3. The microfluidic chip-based radiometric energy dispersive spectroscopy detection system as described in claim 1, characterized in that, Both the upper-layer chip and the lower-layer chip are rectangular.

4. The microfluidic chip-based radiometric energy dispersive spectroscopy detection system as described in claim 1, characterized in that, The inlet and outlet are spaced apart from each other on the left and right.

5. The microfluidic chip-based radiometric energy dispersive spectroscopy detection system as described in claim 1, characterized in that, The detection cell is located at the center of the bottom of the upper chip.

6. The microfluidic chip-based radiometric energy dispersive spectroscopy detection system as described in claim 1, characterized in that, The detection pool is a planar spiral shape.

7. The microfluidic chip-based radiometric energy dispersive spectroscopy detection system as described in claim 1, characterized in that, The vertical annular shielding shell is a metal shielding shell.

8. The microfluidic chip-based radiometric energy dispersive spectroscopy detection system as described in claim 1, characterized in that, The solid-state scintillator is cuboid in shape, the vertical annular shielding shell is a vertical rectangular annular shielding shell, and the photoelectric conversion module is rectangular.

9. The microfluidic chip-based radiometric energy dispersive spectroscopy detection system as described in claim 1, characterized in that, The bottom of the lower chip has a vertically oriented groove located below the detection cell. The photoelectric conversion module is located below the groove opening and is embedded in the groove opening. The solid scintillator is embedded in the groove, and the vertical annular shielding shell is embedded in the groove.

10. A microfluidic chip-based method for detecting radioactive energy dispersive spectroscopy, characterized in that, The process is performed using the microfluidic chip-based radiometric energy dispersive spectroscopy detection system as described in claim 1, and includes the following steps: (1) The radioactive liquid to be tested is delivered to the inlet through the radioactive liquid injection module, and then the radioactive liquid to be tested flows through the detection pool and flows out through the outlet; (2) During the process of the radioactive liquid to be detected flowing through the detection cell, the solid scintillator converts the γ-rays emitted by the radioactive liquid to be detected into light signals; (3) The power supply module supplies power to the photoelectric conversion module and the amplifier circuit module respectively; (4) The photoelectric conversion module captures the optical signal and converts the optical signal into a voltage signal, and then sends the voltage signal to the amplification circuit module; (5) The amplifier circuit module receives the voltage signal and converts the voltage signal into a pulse signal, and then sends the pulse signal to the AD sampling module; (6) The AD sampling module receives the pulse signal and converts the pulse signal into a digital signal, and then sends the digital signal to the signal processing module; (7) The signal processing module receives the digital signal and performs digitization processing on the digital signal to obtain a digitized signal, and then sends the digitized signal to the host computer terminal. (8) The host computer terminal receives the digitized signal and performs energy spectrum reconstruction and analysis based on the digitized signal to realize the identification of radioactive isotope types and the display of energy spectrum output.

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