A dual-mode fluorescence sensing chip and system based on micro-ring resonance enhancement

Abstract

The application relates to a double-mode fluorescence sensing chip and system based on micro-ring resonance enhancement, which comprises a chip body, the chip body is provided with a micro-ring resonator, a to-be-measured substance flow channel, an input grating coupler and an output grating coupler; the micro-ring resonator is a ring-shaped optical waveguide, and an organic fluorescent material sensitive film is arranged on the upper surface of the micro-ring resonator; the to-be-measured substance flow channel is arranged above the organic fluorescent material sensitive film, the organic fluorescent material sensitive film is located in a reaction cavity, and the reaction cavity is communicated with the to-be-measured substance flow channel. The high-Q characteristic of the micro-ring resonator cavity is utilized to convert wide-spectrum fluorescence into a sharp resonance peak, the signal strength is greatly improved, and wide-spectrum background noise is effectively filtered out. Nonlinear response is generated through the synergistic effect of fluorescence quenching and resonance wavelength shift, the detection limit reaches the sub-ppb level, the detection sensitivity is significantly improved, and the trace analysis requirement is met.

Description

Technical Field

[0001] This invention belongs to the field of gas sensing and photonic integrated device technology, and in particular relates to a dual-mode fluorescence sensing chip and system based on microring resonance enhancement. Background Technology

[0002] Fluorescent gas sensing technology holds an important position in the field of trace gas detection due to its excellent specificity and selectivity for target gases. However, traditional fluorescent gas sensing systems often use discrete optical elements to construct the optical path, resulting in a large overall system size, low integration, complex optical path adjustment, and poor stability. This makes it difficult to meet the application requirements of modern analytical instruments for miniaturization, portability, low cost, and high stability.

[0003] To overcome the aforementioned problems, the integration of fluorescence sensing technology and on-chip photonic integration technology has become an important development trend. On-chip photonic integration technology can achieve miniaturized integration of sensing units, significantly improving system integration. However, current fluorescence sensing solutions based on on-chip integration generally face the bottleneck of insufficient fluorescence signal gain. Under low-concentration gas detection conditions, the fluorescence signal is easily drowned out by background noise, making it difficult to meet the requirements of trace analysis in terms of detection sensitivity. Summary of the Invention

[0004] The main objective of this invention is to propose a dual-mode fluorescence sensing chip and system based on microring resonance enhancement, which can effectively solve the problems in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A dual-mode fluorescence sensing chip based on microring resonance enhancement includes a chip body, the chip body having:

[0007] The microring resonator is a ring-shaped optical waveguide, and an organic fluorescent material sensitive film is disposed on the upper surface of the microring resonator.

[0008] The analyte flow channel is positioned above the organic fluorescent material sensitive film, which is located in the reaction chamber. The reaction chamber is connected to the analyte flow channel. When the analyte flows through the reaction chamber, it can interact chemically and physically with the organic fluorescent material sensitive film, causing fluorescence quenching and fluorescence resonance wavelength shift.

[0009] An input grating coupler is used to guide incident light to the microring resonator;

[0010] An output grating coupler is used to export the fluorescence signal after resonance enhancement by the microring resonator.

[0011] Preferably, the chip body also has a multimode interference coupler and a reference straight waveguide. The surface of the reference straight waveguide is also provided with an organic fluorescent material sensitive film. The input grating coupler couples the incident light to the multimode interference coupler. The multimode interference coupler uniformly distributes the light to multiple optical waveguides. The multiple optical waveguides include at least a first optical waveguide connected to the microring resonator and a second optical waveguide connected to the reference straight waveguide.

[0012] Preferably, the thickness of the microring resonator is in the range of 170-180 nm, and the width is in the range of 200-300 nm.

[0013] Preferably, the grating period of the input grating coupler and the output grating coupler is 360-450nm, and the duty cycle is 0.5.

[0014] Preferably, the width of the channel for the substance to be tested is 10-50 μm and the height is 5-20 μm.

[0015] Preferably, the thickness of the organic fluorescent material sensitive film is 30-100 nm, wherein the organic fluorescent material is selected from rhodamine-based, coumarin-based, or BODIPY-based fluorescent materials.

[0016] Preferably, the chip body comprises, from bottom to top, a substrate layer, a lower cladding layer, a waveguide layer, an upper cladding layer, and a packaging plate. The micro-ring resonator is formed in the waveguide layer, the material under test (MTBT) channel is formed between the upper cladding layer and the packaging plate, and the packaging plate is further provided with an incident port and an exit port that communicate with the MTBT channel. The reaction chamber is formed in the upper cladding layer and communicates with the MTBT channel.

[0017] Preferably, the substrate layer is made of glass, aluminum nitride, ceramic, metal or plastic, the waveguide layer is made of silicon nitride, and the upper cladding layer, lower cladding layer and encapsulation plate are made of silicon dioxide and silicon oxynitride, or any combination of one or more of these materials.

[0018] The present invention also provides an enhanced fluorescence sensing system based on a microring resonator, comprising the dual-mode fluorescence sensing chip described above, and:

[0019] A laser source is used to generate and introduce excitation light to the input grating coupler of the dual-mode fluorescence sensing chip;

[0020] The flow control module is used to control the flow rate and velocity of the analyte flowing into the analyte channel of the dual-mode fluorescence sensor chip.

[0021] The detection system is used to receive and process the fluorescence signal exported from the output grating coupler, and analyze it to obtain the detection result;

[0022] The display module is used to display and record the detection results.

[0023] This invention provides a dual-mode fluorescence sensing chip and system based on microring resonance enhancement, which has the following advantages:

[0024] 1. This invention utilizes the high Q characteristics of a micro-ring resonator to enhance and shape the fluorescence signal at a specific wavelength, transforming the broadband fluorescence into a sharp resonant peak, which significantly improves the signal intensity while effectively filtering out broadband background noise.

[0025] 2. In this invention, the analyte interacts with the sensitive film of the organic fluorescent material in the reaction chamber, causing fluorescence quenching (chemical mechanism) and resonant wavelength shift (physical mechanism). The synergistic effect of these two mechanisms produces a nonlinear response, enabling the detection limit to reach the sub-ppb level, significantly improving detection sensitivity and meeting the needs of trace analysis. Simultaneously, by constructing a dual-mode response fingerprint through simultaneous demodulation of fluorescence intensity and wavelength shift, highly selective identification of the target analyte is achieved.

[0026] 3. The laser is coupled from the input grating into the multimode interference coupler, which uniformly distributes the light. The light is then guided through the first optical waveguide to the microring resonator and through the second optical waveguide to the reference straight waveguide. This excites the organic fluorescent material sensitive film on the surface of the microring resonator and the reference straight waveguide to generate fluorescence signals. The enhanced fluorescence signal from the microring resonator is compared and analyzed with the ordinary fluorescence signal from the straight waveguide. The common interference signals of the two are subtracted, and only the specific signals generated by the interaction between the target material and the fluorescent film (fluorescence quenching, wavelength shift) are retained, which greatly reduces the detection error and improves the reliability of the results. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the planar structure of the dual-mode fluorescence sensing chip of the present invention.

[0028] Figure 2 This is a cross-sectional structural diagram of the dual-mode fluorescence sensing chip of the present invention.

[0029] Figure 3 This is a schematic diagram illustrating the working principle of the dual-mode fluorescence sensor chip of the present invention.

[0030] Figure 4 This is the fluorescence resonance spectrum output by the microring resonator of this invention.

[0031] Figure 5 This is a schematic diagram showing the changes in fluorescence spectra (wavelength and intensity) before and after the application of different concentrations of the analyte in this invention.

[0032] Figure 6 This is a schematic diagram illustrating the functional relationship between the fluorescence quenching rate and offset of the present invention and the concentration of the substance to be detected.

[0033] In the figure: 101, incident light; 102, input grating coupler; 103, multimode interference coupler; 104, material under test flow channel; 1041, incident port; 1042, output port; 105, micro-ring resonator; 106, reference straight waveguide; 107, output grating coupler; 201, fluorescence signal; 202, organic fluorescent material sensitive film; 203, photosensitive element; 2031, filter; 204, reaction cavity; 301, substrate layer; 302, lower cladding layer; 303, waveguide layer; 304, upper cladding layer; 305, packaged plate. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0035] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," 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 this invention and 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 limiting this invention.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may 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.

[0037] Reference Figure 1-3This invention provides a dual-mode fluorescence sensing chip based on microring resonance enhancement, comprising a chip body, the chip body having:

[0038] The microring resonator 105 is a ring optical waveguide, and an organic fluorescent material sensitive film 202 is disposed on the upper surface of the microring resonator 105.

[0039] The test substance flow channel 104 is disposed above the organic fluorescent material sensitive film 202, which is located in the reaction chamber 204. The reaction chamber 204 is connected to the test substance flow channel 104. When the test substance flows through the reaction chamber 204, it can have chemical and physical interactions with the organic fluorescent material sensitive film 202, causing fluorescence quenching and fluorescence resonance wavelength shift.

[0040] An input grating coupler 102 is used to guide incident light 101 to the microring resonator 105;

[0041] The output grating coupler 107 is used to export the fluorescence signal 201 after being enhanced by the resonance of the microring resonator 105.

[0042] In use, the dual-mode fluorescence sensing chip of the present invention introduces incident light 101 (laser) into a microring resonator 105 via an input grating coupler 102. The laser excites the organic fluorescent material sensitive film 202 on the upper surface of the microring resonator 105 through an evanescent field, generating a fluorescence signal 201. This fluorescence signal 201 is then coupled back into the microring resonator 105 for transmission via the surface evanescent field effect. Within the microring resonator 105, the fluorescence component with a wavelength matching the resonant mode of the microring resonator 105 resonates cyclically and accumulates energy, achieving selective enhancement and spectral shaping, forming discrete high-Q resonance peaks (see reference). Figure 4 This invention utilizes the high Q characteristics of a microring resonator to enhance and shape the spectrum of fluorescence signals at specific wavelengths, transforming broad-spectrum fluorescence into sharp resonant peaks, significantly improving signal intensity, and effectively filtering out broad-spectrum background noise. The fluorescence signal 201, enhanced by the microring resonator 105, can be exported through the output grating coupler 107 and subsequently received by the photosensitive element 203, which can be a fluorescence spectrometer or a single-pixel image sensor. To improve the signal-to-noise ratio, a filter 2031 can be added in front of the photosensitive element 203 to filter out stray light of non-target wavelengths.

[0043] When the analyte flows through the analyte flow channel 104, it interacts with the organic fluorescent material sensitive film 202 in the reaction chamber 204, resulting in two simultaneous sensitive effects: First, the analyte reacts chemically with the organic fluorescent material sensitive film 202, causing quenching of fluorescence intensity; the degree of brightness change is related to the concentration of the analyte. Second, the analyte adsorbs onto the organic fluorescent material sensitive film 202, causing a change in its refractive index, which in turn causes a shift in the fluorescence resonance wavelength; the magnitude of this shift is also related to the concentration of the analyte (see reference). Figure 5 , Figure 6 In this invention, the analyte interacts with the sensitive film 202 of the organic fluorescent material in the reaction chamber 204, causing fluorescence quenching (chemical mechanism) and resonant wavelength shift (physical mechanism). The synergistic effect of these two mechanisms produces a nonlinear response, enabling the detection limit to reach the sub-ppb level, significantly improving detection sensitivity and meeting the needs of trace analysis. Simultaneously, by constructing a dual-mode response fingerprint through simultaneous demodulation of fluorescence intensity and wavelength shift, highly selective identification of target analytes (such as MPEA) is achieved.

[0044] In a preferred embodiment, the chip body also includes a multimode interference coupler 103 and a reference straight waveguide 106. The surface of the reference straight waveguide 106 is also provided with an organic fluorescent material sensitive film 202, which is also located in the corresponding reaction cavity 204. The reaction cavity 204 is connected to the test material flow channel 104. The input grating coupler 102 couples the incident light 101 to the multimode interference coupler 103. The multimode interference coupler 103 uniformly distributes the light to multiple optical waveguides. The multiple optical waveguides include at least a first optical waveguide connected to the micro-ring resonator 105 and a second optical waveguide connected to the reference straight waveguide 106.

[0045] A laser beam is coupled from the input grating into a multimode interference coupler 103, which uniformly distributes the light. The light is then guided through a first optical waveguide to a micro-ring resonator 105 and through a second optical waveguide to a reference straight waveguide 106, respectively, to excite the organic fluorescent material sensitive films 202 on the surfaces of the micro-ring resonator 105 and the reference straight waveguide 106 to generate fluorescence signals 201. Similarly, when the analyte flows through the channel, it also interacts with the organic fluorescent material sensitive films 202 on the surfaces of the micro-ring resonator 105 and the reference straight waveguide 106. Non-target factors such as ambient temperature, humidity, fluorescent material aging, and laser intensity fluctuations have the same effect on the fluorescence signals of both. By comparing and analyzing the enhanced fluorescence signal of the micro-ring resonator 105 with the ordinary fluorescence signal of the straight waveguide, the common interference signals are subtracted, and only the specific signals generated by the interaction between the target material and the fluorescent film (fluorescence quenching, wavelength shift) are retained, significantly reducing detection errors and improving the reliability of the results.

[0046] As a preferred embodiment, the thickness of the microring resonator 105 ranges from 170 to 180 nm, and the width ranges from 200 to 300 nm.

[0047] In a preferred embodiment, the grating period of the input grating coupler 102 and the output grating coupler 107 is 360-450nm, and the duty cycle is 0.5.

[0048] As a preferred embodiment, the width of the test material flow channel 104 is 10-50 μm and the height is 5-20 μm.

[0049] As a preferred embodiment, the thickness of the organic fluorescent material sensitive film 202 is 30-100 nm, wherein the organic fluorescent material is selected from rhodamine-based, coumarin-based, or BODIPY-based fluorescent materials.

[0050] In a preferred embodiment, the chip body comprises, from bottom to top, a substrate layer 301, a lower cladding layer 302, a waveguide layer 303, an upper cladding layer 304, and a package plate 305. The micro-ring resonator 105 is formed in the waveguide layer 303. The material under test channel 104 is formed between the upper cladding layer 304 and the package plate 305. The package plate 305 is also provided with an incident port 1041 and an exit port 1042 that communicate with the material under test channel 104. The reaction cavity 204 is formed in the upper cladding layer 304 and communicates with the material under test channel 104.

[0051] This invention is fabricated using standard silicon-based photonic integration technology, integrating optical paths, sensing units, and microchannels onto a single chip, resulting in a compact structure, small size, portability, and low cost.

[0052] In a preferred embodiment, the substrate layer 301 is made of glass, aluminum nitride, ceramic, metal or plastic, the waveguide layer 303 is made of silicon nitride, and the upper cladding layer 304, the lower cladding layer 302 and the encapsulation plate 305 are made of silicon dioxide and silicon oxynitride, or any combination of one or more of these materials.

[0053] The present invention also provides an enhanced fluorescence sensing system based on a microring resonator, comprising the above-mentioned dual-mode fluorescence sensing chip, and:

[0054] A laser source is used to generate and guide laser light to the input grating coupler 102 of the dual-mode fluorescence sensing chip;

[0055] The flow control module is used to control the flow rate and velocity of the analyte flowing into the analyte flow channel 104 of the dual-mode fluorescence sensor chip.

[0056] The detection system is used to receive and process the fluorescence signal 201 derived from the output grating coupler 107, and analyze it to obtain the detection result;

[0057] The display module is used to display and record the detection results.

[0058] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. 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 of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dual-mode fluorescence sensing chip based on microring resonance enhancement, characterized in that, Includes a chip body, the chip body having: The microring resonator is a ring-shaped optical waveguide, and an organic fluorescent material sensitive film is disposed on the upper surface of the microring resonator. The analyte flow channel is positioned above the organic fluorescent material sensitive film, which is located in the reaction chamber. The reaction chamber is connected to the analyte flow channel. When the analyte flows through the reaction chamber, it can interact chemically and physically with the organic fluorescent material sensitive film, causing fluorescence quenching and fluorescence resonance wavelength shift. An input grating coupler is used to guide incident light to the microring resonator; An output grating coupler is used to export the fluorescence signal after resonance enhancement by the microring resonator.

2. The dual-mode fluorescence sensing chip based on microring resonance enhancement according to claim 1, characterized in that, The chip body also has a multimode interference coupler and a reference straight waveguide. The surface of the reference straight waveguide is also provided with an organic fluorescent material sensitive film. The input grating coupler couples the incident light to the multimode interference coupler. The multimode interference coupler uniformly distributes the light to multiple optical waveguides. The multiple optical waveguides include at least a first optical waveguide connected to the micro-ring resonator and a second optical waveguide connected to the reference straight waveguide.

3. A dual-mode fluorescence sensing chip based on microring resonance enhancement according to claim 1 or 2, characterized in that, The thickness of the microring resonator ranges from 170 to 180 nm, and the width ranges from 200 to 300 nm.

4. A dual-mode fluorescence sensing chip based on microring resonance enhancement according to claim 1 or 2, characterized in that, The grating period of the input grating coupler and the output grating coupler is 360-450nm, and the duty cycle is 0.

5.

5. A dual-mode fluorescence sensing chip based on microring resonance enhancement according to claim 1 or 2, characterized in that, The width of the channel for the substance to be tested is 10-50 μm, and the height is 5-20 μm.

6. A dual-mode fluorescence sensing chip based on microring resonance enhancement according to claim 1 or 2, characterized in that, The thickness of the organic fluorescent material sensitive film is 30-100 nm, wherein the organic fluorescent material is selected from rhodamine-based, coumarin-based, or BODIPY-based fluorescent materials.

7. A dual-mode fluorescence sensing chip based on microring resonance enhancement according to claim 1 or 2, characterized in that, The chip body comprises, from bottom to top, a substrate layer, a lower cladding layer, a waveguide layer, an upper cladding layer, and a packaging plate. The micro-ring resonator is formed in the waveguide layer. The material under test (MTBT) channel is formed between the upper cladding layer and the packaging plate. The packaging plate also has an incident port and an exit port that communicate with the MTBT channel. The reaction chamber is formed in the upper cladding layer and communicates with the MTBT channel.

8. A dual-mode fluorescence sensing chip based on microring resonance enhancement according to claim 7, characterized in that, The substrate layer is made of glass, aluminum nitride, ceramic, metal or plastic, the waveguide layer is made of silicon nitride, and the upper cladding layer, lower cladding layer and encapsulation plate are made of silicon dioxide and silicon oxynitride, or any combination of one or more of these materials.

9. An enhanced fluorescence sensing system based on a microring resonator, characterized in that, Including the dual-mode fluorescence sensing chip according to any one of claims 1-8, and: A laser source is used to generate and introduce excitation light to the input grating coupler of the dual-mode fluorescence sensing chip; The flow control module is used to control the flow rate and velocity of the analyte flowing into the analyte channel of the dual-mode fluorescence sensor chip. The detection system is used to receive and process the fluorescence signal exported from the output grating coupler, and analyze it to obtain the detection result; The display module is used to display and record the detection results.

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