A photosensitizer and tissue oxygen synchronous measurement device and a measurement method thereof

Abstract

The application discloses a photosensitizer and tissue oxygen synchronous measurement device, and belongs to the technical field of photoelectric measurement. The application uses a semiconductor diode laser as an excitation source, the emission wavelength of which is determined according to the absorption characteristics of oxygen sensing material and photosensitizer, a laser beam is coupled into a detection optical fiber to form excitation light through optical components, so that the excitation light can excite the oxygen sensing material and the photosensitizer at the same time, the oxygen sensing material with near-infrared emission is used, the phosphorescence emission wavelength of which is far away from the fluorescence of the photosensitizer, the spectral intensity of near-infrared is used to determine the tissue oxygen concentration, the spectral intensity of red light is used to determine the concentration of the photosensitizer, in addition, the fluorescence and phosphorescence of the oxygen probe are both oxygen-dependent, so that the fluorescence intensity of the oxygen probe in the red light region can be accurately removed, thereby avoiding the influence of the fluorescence intensity of the oxygen probe on the detection of the photosensitizer fluorescence, and then realizing that the fluorescence for characterizing the photosensitizer concentration and the phosphorescence for characterizing the oxygen concentration are not overlapped, and realizing the synchronous measurement of the photosensitizer and the tissue oxygen.

Description

Technical Field

[0001] This invention relates to a device for simultaneously measuring photosensitizer and tissue oxygen, belonging to the field of photoelectric measurement technology. Background Technology

[0002] Photodynamic therapy (PDT) is an advanced tumor treatment technology based on photochemical reactions. The cell-killing mechanism involves first applying excitation light of a specific wavelength to the treatment site. Photosensitizer molecules within the tissue are excited and transition from the ground state to a singlet excited state. During their return to the ground state, the excited photosensitizer has a certain probability of transferring energy to surrounding oxygen molecules, generating highly oxidizing singlet oxygen. This singlet oxygen reacts with adjacent biomolecules, producing toxic effects on cells, ultimately leading to cell damage or death. Studies have shown that cell viability under PDT is regulated by photosensitizer and oxygen concentrations, exhibiting an exponential (e) relationship with their product. Therefore, during PDT, the photosensitizer and oxygen concentrations at the tumor and peritumoral sites need to be monitored to ensure controllable PDT efficacy.

[0003] Existing technologies utilize fluorescence spectroscopy to measure photosensitizer and oxygen concentrations in tissues. However, these methods typically employ separate measurements, making it impossible to obtain numerical values ​​for photosensitizer and oxygen concentrations at the same location within the tissue. A challenge in implementing simultaneous measurements lies in the spectral overlap between commonly used photosensitizers and oxygen sensing materials around 630 nm. Spectral interpretation methods cannot guarantee measurement accuracy, and when using a single fiber optic probe, the spectral interference between photosensitizer and oxygen measurements needs to be addressed. Therefore, this invention proposes a method for single-wavelength excitation, single-fiber transmission, and detection to simultaneously measure photosensitizer and tissue oxygen concentrations at the same location within tissue. Summary of the Invention

[0004] To address the problem of simultaneous measurement of photosensitizers and tissue oxygen caused by spectral overlap, this invention provides a device and method for simultaneous measurement of photosensitizers and tissue oxygen.

[0005] The technical method of the present invention:

[0006] One objective of this invention is to provide a device for simultaneous measurement of photosensitizer and tissue oxygen, which includes an optical module and an electrical module. The electrical module performs photoelectric conversion and signal processing on the optical information collected and transmitted by the optical module.

[0007] The optical module is a rectangular dark box divided into left and right compartments. The left compartment contains a laser 1, a first optical component 9, a first convex lens 10, and a fiber optic coupler 11. The right compartment contains a first photomultiplier tube 3, a second convex lens 4, a second photomultiplier tube 5, a third convex lens 6, and a second optical component 7. The fiber optic coupler 11, the first convex lens 10, the first optical component 9, the second optical component 7, the third convex lens 6, and the second photomultiplier tube 5 are arranged sequentially on the same horizontal straight line a. The laser 1 is located directly above the first optical component 9, the first photomultiplier tube 3 is located directly above the second optical component 7, and the second convex lens 4 is positioned between the first photomultiplier tube 3 and the second optical component 7. The fiber optic coupler 11 connects the inner and outer sides of the dark box. The detection fiber is located outside the dark box and one end is screwed onto the fiber optic coupler 11. Oxygen sensing material is coated on the exit end face of the detection fiber to form an oxygen sensing film. The left and right compartments are separated by a black aluminum alloy partition plate 2, and a glass window is located on the black aluminum alloy partition plate 2 at the position corresponding to the horizontal straight line a.

[0008] The electrical module includes a high-voltage source, a laser driver, a preamplifier, a data acquisition card, and an industrial computer. The high-voltage source powers the first photomultiplier tube 3 and the second photomultiplier tube 5. The laser driver controls the laser. The photomultiplier tubes convert the optical signal into a current signal and send it to the preamplifier. The preamplifier converts the current signal into a voltage signal and amplifies and filters it. The data acquisition card collects data, and the industrial computer processes the electrical signals to calculate the sensitizer and tissue oxygen concentration.

[0009] Further specifying, laser 1 is a semiconductor diode laser with a center wavelength of 425 nm.

[0010] Further defined, the beam emitted by the laser 1 is coupled into the detection fiber through the first optical component 9 and the first convex lens 10 to form excitation light.

[0011] Further defined, the first optical component 9 is a combination of multiple lenses, with a glass window on the side facing the laser 1, a glass window on the side facing the first convex lens 10, a 475 nm long-pass filter on the side facing the right compartment, and a beam splitter placed at 45° in the middle.

[0012] Furthermore, the beam splitter in the first optical component 9 is a 450 nm long-wavelength pass.

[0013] Further specifying, the output end face of the detection fiber is coated with an oxygen-sensing coating, which is a tetraphenyl-benzoporphyrin palladium based on silica gel.

[0014] Further defined, the second optical component 7 is a combination of multiple lenses, with a 500 nm long-pass filter on the side facing the left chamber, a 790 nm narrow-band filter on the side facing the third convex lens 6, a 630 nm narrow-band filter on the side facing the second convex lens 4, and a beam splitter placed at 45° in the middle.

[0015] Furthermore, the beam splitter in the second optical component 7 is a 730 nm long-wavelength pass.

[0016] Furthermore, the optical module is located above the electrical module, and the optical module and the electrical module are separated by a copper plate.

[0017] The second objective of this invention is to provide a method for simultaneous detection of photosensitizer and oxygen concentration using a single optical fiber. This method utilizes a simultaneous photosensitizer and tissue oxygen measurement device, and the specific steps are as follows:

[0018] S1, Insert the puncture fiber with an oxygen-sensing film into the tissue to be tested, which has been injected with photosensitizer, and fix it.

[0019] S2, turn on laser 1, first photomultiplier tube 3 and second photomultiplier tube 5;

[0020] S3, generated by an oxygen-sensing thin film in the near-infrared band λ The phosphorescence emission intensity of 1 was used to calculate the tissue oxygen concentration based on calibration curve I. C 1. The equation of calibration curve I is as follows:

[0021] (1)

[0022] In the formula, optical parameters OP 1 indicates phosphorescence emitted by the oxygen sensing film. I (λ1) The intensity ratio in anaerobic and aerobic environments, I 0(λ1) It is the phosphorescence intensity in an oxygen-free environment; a 1. b 1. t 1 are all fitting parameters of exponential equation I;

[0023] S4, determined by tissue oxygen concentration C 1. Calculate the oxygen sensing film under red light based on calibration curve II. λ Fluorescence intensity value near wavelength 2 I f2 The equation of calibration curve II is as follows:

[0024] (2)

[0025] In the formula, optical parameters OP 2 represents the fluorescence emitted by the oxygen sensing film.I (λ2) The intensity ratio in anaerobic and aerobic environments, I 0(λ2) It is the fluorescence intensity in an oxygen-free environment; a 2. b 2. t 2 are the fitting parameters of exponential equation II;

[0026] S5, by subtracting the oxygen sensing film in λ The fluorescence intensity at wavelength 2 is used to obtain the true fluorescence intensity value of the photosensitizer in this wavelength band, and the photosensitizer concentration is calculated according to calibration curve III. C 2, OP 3 is λ The fluorescence intensity of the photosensitizer at wavelength 2;

[0027] (3)

[0028] In the formula, a 3. b 3 represents the fitting parameters for linear equation III;

[0029] S6. Repeat steps S3 to S5 to continuously measure the photosensitizer and oxygen concentration.

[0030] Further specifying, the photosensitizer is protoporphyrin IX (PpIX).

[0031] Compared with the prior art, the present invention has the following advantages:

[0032] (1) The present invention uses a semiconductor diode laser as the excitation source. Its emission wavelength is determined according to the absorption characteristics of the oxygen sensing material and the photosensitizer. The laser beam is coupled into the detection fiber through an optical component to form an excitation light, ensuring that the excitation light can simultaneously excite the oxygen sensing film and the photosensitizer. The oxygen sensing film with near-infrared emission has a phosphorescence emission wavelength far away from the photosensitizer fluorescence, so that the tissue oxygen concentration can be determined by the near-infrared spectral intensity and the photosensitizer concentration can be determined by the spectral intensity in the red region. In addition, the oxygen sensing film not only has near-infrared phosphorescence emission, but also fluorescence emission in the red region. Studies have found that the fluorescence and phosphorescence of this oxygen sensing film are both oxygen-dependent. Therefore, the fluorescence intensity of the oxygen sensing film in the red region can be accurately eliminated, thereby avoiding its influence on the detection of photosensitizer fluorescence. This achieves non-overlapping fluorescence used to characterize photosensitizer concentration and phosphorescence used to characterize oxygen concentration, realizing the synchronous measurement of photosensitizer and tissue oxygen.

[0033] (2) The present invention utilizes the fact that the fluorescence and phosphorescence intensity of the oxygen sensing film are both oxygen-dependent, thus the photosensitizer fluorescence can be quantitatively separated, thereby ensuring the measurement accuracy of the photosensitizer concentration. Attached Figure Description

[0034] Figure 1 A schematic diagram of the single-fiber synchronous detection and oxygen concentration measurement device provided by the present invention;

[0035] Figure 2 This is a schematic diagram of the optical module in the single-fiber synchronous detection and oxygen concentration measurement device provided by the present invention.

[0036] Figure 3 The absorption and emission spectra of photosensitizers PpIX and PdTPTBP are shown.

[0037] Figure 4 Calibration curve for tissue oxygen concentration;

[0038] Figure 5 This is a calibration curve for the concentration of the photosensitizer;

[0039] In the figure, 1-laser, 2-aluminum alloy partition plate, 3-first photomultiplier tube, 4-second convex lens, 5-second photomultiplier tube, 6-third convex lens, 7-second optical component, 8-glass window, 9-first optical component, 10-first convex lens, 11-fiber optic coupler. Detailed Implementation

[0040] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0042] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0044] Example 1

[0045] Reference Figure 1 and 2 This embodiment specifically describes a single-fiber synchronous detection method for photosensitizer and oxygen concentration measurement, based on the following device. This device's housing comprises upper and lower layers: an upper optical module and a lower electrical module. The optical and electrical modules are separated by a copper plate to achieve electromagnetic shielding. Figure 2 As shown, the specific optical detection module is a cuboid dark box divided into a left compartment and a right compartment. The left compartment contains a laser 1, a first optical component 9, a first convex lens 10, and a fiber optic coupler 11. The right compartment contains a first photomultiplier tube 3, a second convex lens 4, a second photomultiplier tube 5, a third convex lens 6, and a second optical component 7. The fiber optic coupler 11, the first convex lens 10, the first optical component 9, the second optical component 7, the third convex lens 6, and the second photomultiplier tube 5 are arranged sequentially on the same horizontal straight line a. The laser 1 is located directly above the first optical component 9, the first photomultiplier tube 3 is located directly above the second optical component 7, and the second convex lens 4 is positioned between the first photomultiplier tube 3 and the second optical component 7. The fiber optic coupler 11 connects the inner and outer sides of the dark box. The detection fiber is located outside the dark box with one end screwed onto the fiber optic coupler 11, and the other end of the detection fiber is coated with an oxygen sensing film. The left and right compartments are separated by a black aluminum alloy partition plate 2, and a glass window 8 is located on the black aluminum alloy partition plate 2 at the position corresponding to the horizontal straight line a. Laser 1 is a semiconductor diode laser with a wavelength of 425 nm. This configuration ensures that the emission wavelength of laser 1, being a semiconductor diode laser, is determined based on the absorption characteristics of the oxygen sensing material and the photosensitizer, thus guaranteeing that the excitation light can simultaneously excite both the oxygen sensing film and the photosensitizer.

[0046] The first optical component 9 is an assembly containing multiple lenses. The side facing the laser 1 has a glass window, the side facing the first convex lens 10 has a glass window, the side facing the right chamber has a 475 nm long-pass filter, and the middle section has a 450 nm long-pass beam splitter placed at a 45° angle. The second optical component 7 is also an assembly containing multiple lenses. The side facing the left chamber has a 500 nm long-pass filter, the side facing the third convex lens 6 has a 790 nm narrowband filter, the side facing the second convex lens 4 has a 630 nm narrowband filter, and the middle section has a 730 nm long-pass beam splitter placed at a 45° angle.

[0047] The output end face of the detection fiber is coated with an oxygen-sensing thin film, which is a tetraphenyl-benzoporphyrin palladium film based on silica gel. With this configuration, the beam emitted by the laser 1 is coupled into the detection fiber through the first optical component 9 and the first convex lens 10 to form excitation light. The excitation light excites the fluorescence emitted by the photosensitizer. The fluorescence collected by the detection fiber is paralleled by the fiber coupler 11 and the first convex lens 10, passes through the glass window 8 on the black aluminum alloy partition plate 2, and is transmitted to the second optical component 7. After being split and filtered by the second optical component 7, it is converged by the second convex lens 4 and the third convex lens 6 to the first photomultiplier tube 3 and the second photomultiplier tube 5, respectively.

[0048] The output end of the probe fiber is coated with an oxygen-sensing thin film, which is a tetraphenyl-benzoporphyrin palladium based on silica gel. With this setup, taking the measurement of the photosensitizer protoporphyrin IX (PpIX) as an example, the absorption and emission spectra of PpIX and PdTPTBP are as follows: Figure 3 Both exhibit strong absorption around 425 nm, therefore laser 1 is a semiconductor laser with a center wavelength of 425 nm. The fluorescence emission spectrum shows that PdTPTBP exhibits phosphorescence emission in the near-infrared region (790 nm), with the phosphorescence intensity depending on the oxygen concentration of the probe's environment. PdTPTBP also exhibits fluorescence emission around 630 nm, with its intensity similarly dependent on the oxygen concentration of the probe's environment. Oxygen sensing materials are not limited to PdTPTBP, but the material used should possess two characteristics: near-infrared emission and the ability to accurately measure fluorescence changes at 630 nm.

[0049] The single-fiber synchronous detection method for photosensitizer and oxygen concentration measurement in this embodiment is as follows:

[0050] S1, insert the probe puncture fiber with oxygen sensing film (PdTPTBP&Sol-gel) into the tissue to be tested injected with photosensitizer protoporphyrin IX (PpIX) and fix it;

[0051] S2, turn on laser 1, first photomultiplier tube 3 and second photomultiplier tube 5;

[0052] S3, the wavelengths to be measured are 630 nm and 790 nm, respectively, determined by the emission spectra of PpⅨ and PdTPTBP;

[0053] Tissue oxygen concentration was calculated from calibration curve I based on the phosphorescence emission intensity of the PdTPTBP oxygen sensing film at 790 nm in the near-infrared band. C 1. The equation of calibration curve I is as follows:

[0054] (4)

[0055] In the formula, optical parameters OP 1 indicates phosphorescence emitted by the oxygen sensing film. I (790nm) The intensity ratio in anaerobic and aerobic environments, I 0(790nm) It is the phosphorescence intensity in an oxygen-free environment, and the recording wavelength of the phosphorescence intensity is 790 nm; a 1. b 1. t 1 are all fitting parameters of exponential equation I;

[0056] S4, the oxygen sensing film is calculated based on the tissue oxygen concentration according to calibration curve II. λ Fluorescence intensity value near 2 (630 nm) I f2 The equation of calibration curve II is as follows:

[0057] (5)

[0058] In the formula, optical parameters OP 2 represents the fluorescence emitted by the oxygen sensing film. I (630nm) The intensity ratio in anaerobic and aerobic environments, I 0(630nm) It is the fluorescence intensity in an oxygen-free environment, and the recording wavelength of the fluorescence intensity is 630 nm; a 2. b 2. t 2 are the fitting parameters of exponential equation II.

[0059] S5, by subtracting the oxygen sensing film in λ The fluorescence intensity at point 2 is used to obtain the true fluorescence intensity value of the photosensitizer in this wavelength band, and the photosensitizer concentration is calculated based on calibration curve III. C 2.

[0060] (6)

[0061] In the formula, a 3. b 3 represents the fitting parameters for linear equation III;

[0062] S6. Repeat steps S3 to S5 to continuously measure the photosensitizer and oxygen concentration.

[0063] The test tissue used was a simulated tissue fluid, which was a diluted fat emulsion solution. A cuvette containing 3 mL of the simulated tissue fluid was used. 0.2 mL of an aqueous solution of sodium sulfite was added to the cuvette. Sodium sulfite consumes oxygen in the solution, and the oxygen concentration can be controlled by adjusting the amount of sodium sulfite added. Simultaneously, 0.2 mL of ethanol solutions of different concentrations of PpIX were added to the cuvette.

[0064] The concentrations of photosensitizer and oxygen in simulated tissue fluid were detected using the aforementioned measuring device and method. OP 1. OP 2 and oxygen concentration C The relationship curve of 1 is as follows Figure 4 As shown, the two are related by an e-exponential relationship, and their calibration equations are Equation (7) and Equation (8), respectively. (7)

[0065] (8)

[0066] OP 3 and PpIX concentration C The relationship curve of 2 is as follows Figure 5 As shown, the two are linearly related, and the calibration equation is formula (9).

[0067] (9)

[0068] Finally, it should be noted that the above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for simultaneous measurement of photosensitizer and tissue oxygen, characterized in that, It includes an optical module and an electrical module. The electrical module performs photoelectric conversion and signal processing on the optical information collected and transmitted by the optical module. The optical module is a rectangular dark box divided into a left compartment and a right compartment. The left compartment contains a laser (1), a first optical component (9), a first convex lens (10), and a fiber coupler (11); the right compartment contains a first photomultiplier tube (3), a second convex lens (4), a second photomultiplier tube (5), a third convex lens (6), and a second optical component (7). The fiber coupler (11), the first convex lens (10), the first optical component (9), the second optical component (7), the third convex lens (6), and the second photomultiplier tube (5) are arranged sequentially in the left compartment and right compartment. On the same horizontal straight line a, the laser (1) is located directly above the first optical component (9), the first photomultiplier tube (3) is located directly above the second optical component (7), and the second convex lens (4) is located between the first photomultiplier tube (3) and the second optical component (7); the fiber optic coupler (11) connects the inner and outer sides of the dark box, the detection fiber is located outside the dark box and one end is screwed on the fiber optic coupler (11), and the other end of the detection fiber is coated with an oxygen sensing film, which has near-infrared phosphorescence emission and fluorescence emission in the red light region of 630 nm; the left and right compartments are separated by a black aluminum alloy partition plate (2), and a glass window (8) is located on the black aluminum alloy partition plate (2) at the position corresponding to the horizontal straight line a. The electrical module includes a high-voltage source, a laser driver, a preamplifier, a data acquisition card, and an industrial computer. The high-voltage source powers the first photomultiplier tube (3) and the second photomultiplier tube (5). The laser driver controls the laser. The photomultiplier tube converts the light signal into a current signal and sends it to the preamplifier. The preamplifier converts the current signal into a voltage signal and amplifies and filters it. The data acquisition card collects data, and the industrial computer processes the electrical signal to calculate the sensitizer and tissue oxygen concentration.

2. The photosensitizer and tissue oxygen simultaneous measurement device according to claim 1, characterized in that, The laser (1) is a semiconductor diode laser with a center wavelength of 425 nm.

3. The photosensitizer and tissue oxygen simultaneous measurement device according to claim 1, characterized in that, The beam emitted by the laser (1) is coupled into the detection fiber through the first optical component (9) and the first convex lens (10) to form excitation light.

4. The photosensitizer and tissue oxygen synchronous measurement device according to claim 1, characterized in that, The first optical component (9) is a combination of multiple lenses. The side facing the laser (1) is a glass window, the side facing the first convex lens (10) is a glass window, the side facing the right compartment is a 475 nm long-pass filter, and the middle is a beam splitter placed at 45°.

5. The photosensitizer and tissue oxygen simultaneous measurement device according to claim 4, characterized in that, The beam splitter in the first optical component (9) is a 450 nm long-wavelength pass.

6. The photosensitizer and tissue oxygen simultaneous measurement device according to claim 1, characterized in that, The output end face of the detection fiber is coated with an oxygen sensing film, which is a tetraphenyl-benzoporphyrin palladium based on silica gel.

7. The photosensitizer and tissue oxygen simultaneous measurement device according to claim 1, characterized in that, The second optical component (7) is a combination of multiple lenses. The side facing the left compartment is a 500nm long-pass filter, the side facing the third convex lens (6) is a 790nm narrow-band filter, the side facing the second convex lens (4) is a 630nm narrow-band filter, and the middle part is a beam splitter placed at 45°.

8. The photosensitizer and tissue oxygen simultaneous measurement device according to claim 7, characterized in that, The beam splitter in the second optical component (7) is a 730 nm long-wavelength pass.

9. The photosensitizer and tissue oxygen simultaneous measurement device according to claim 1, characterized in that, The optical module is located above the electrical module, and the optical module and the electrical module are separated by a copper plate.

10. A method for simultaneous detection of photosensitizer and oxygen concentration using a single optical fiber, characterized in that, Using the photosensitizer and tissue oxygen synchronous measurement device according to any one of claims 1 to 9, the method is as follows: S1, Insert one end of the detection optical fiber coated with an oxygen sensing film into the tissue to be tested, which has been treated with a photosensitizer, and fix it in place; S2, turn on the laser (1), the first photomultiplier tube (3), and the second photomultiplier tube (5); S3, generated by an oxygen-sensing thin film in the near-infrared band λ The phosphorescence emission intensity of 1 was used to calculate the tissue oxygen concentration based on calibration curve I. C 1. The equation of calibration curve I is as follows: (1) In the formula, optical parameters OP 1 indicates phosphorescence emitted by the oxygen sensing film. I (λ1) The intensity ratio in anaerobic and aerobic environments, I 0(λ1) It is the phosphorescence intensity in an oxygen-free environment; a 1. b 1. t 1 are all fitting parameters of exponential equation I; S4, determined by tissue oxygen concentration C 1. Calculate the oxygen sensing film under red light based on calibration curve II. λ Fluorescence intensity value near wavelength 2 I f2 The equation of calibration curve II is as follows: (2) In the formula, optical parameters OP 2 represents the fluorescence emitted by the oxygen sensing film. I (λ2) The intensity ratio in anaerobic and aerobic environments, I 0(λ2) It is the fluorescence intensity in an oxygen-free environment; a 2. b 2. t 2 are the fitting parameters of exponential equation II; S5, by subtracting the oxygen sensing film in λ The fluorescence intensity at wavelength 2 is used to obtain the true fluorescence intensity value of the photosensitizer in this wavelength band, and the photosensitizer concentration is calculated according to calibration curve III. C 2, OP 3 is λ The fluorescence intensity value of the photosensitizer in the region at wavelength 2; (3) In the formula, a 3. b 3 represents the fitting parameters for linear equation III; S6. Repeat steps S3 to S5 to continuously measure the photosensitizer and oxygen concentration.

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