Method and system for free state molecule interaction analysis of mach-zehnder interferometric structures

Abstract

The application provides a Mach-Zehnder interference structure free-state molecule interaction analysis method and system, in a free system, a light intensity imaging module is used to perform molecule interaction monitoring, through a Mach-Zehnder interference optical path, a refractive index change caused by free system biomolecule combination is converted into a phase difference between two different polarization components formed by a detection light at a detection arm and a reference arm; subsequently, a weak value amplification effect is introduced by near-orthogonal post-selection, so that the small phase difference is converted into a light intensity change, and system noise interference is reduced through light intensity image processing, baseline correction and background subtraction; the application can solve the problems of spatial steric hindrance, limited mass transfer, complex detection process, difficulty in truly reflecting the molecule interaction process in the free system, insufficient sensitivity to weak signals, and easy environmental noise interference in the existing fixed system label-free detection technology, and can realize high-sensitivity, real-time and high-throughput detection of biomolecule interaction in a free solution system.

Description

Technical Field

[0001] This invention relates to the fields of photoelectric sensing and biomedical detection technology, and in particular to a method and system for analyzing the interaction of free-state molecules in Mach-Zehnder interferometer structures. Specifically, it relates to a method and system for analyzing the interaction of free-state molecules in Mach-Zehnder interferometer structures based on the weak measurement principle. Background Technology

[0002] In recent years, with the development of precision medicine, bioanalysis, and point-of-care testing technologies, biomarker detection has placed higher demands on sensitivity, specificity, and detection efficiency. Optical biosensing technology, due to its advantages such as non-invasiveness, resistance to electromagnetic interference, and ability to achieve label-free detection, has become one of the important technical routes in the field of biomolecular detection.

[0003] In existing label-free optical biosensing technologies, methods such as surface plasmon resonance (SPR) mostly employ solid-phase detection, where receptor molecules are pre-fixed onto the surface of the sensor chip before recognizing and binding with the analyte. While this type of method has been widely used, it still suffers from the following drawbacks: First, the fixation of receptor molecules onto the solid surface can lead to steric hindrance, potentially obscuring effective binding sites and affecting the native conformation and biological activity of the receptor molecules. Second, a liquid boundary layer easily forms at the solid-liquid interface, causing mass transfer limitation. When the diffusion rate of the analyte to the interface is lower than its surface binding rate, the measured binding kinetic parameters are prone to deviation, making it difficult to accurately reflect the true interaction process of biomolecules in their free state. Third, the chip surface modification, sealing, cleaning, and regeneration processes are relatively complex, which is detrimental to improving detection throughput and batch-to-batch repeatability.

[0004] Compared to solid-phase detection, molecular interaction detection in free systems eliminates the need for surface fixation of the recognition element. Molecules can diffuse and collide freely in the solution, more closely resembling their natural physiological state. This helps reduce the impact of steric hindrance and mass transfer limitations on the detection results and simplifies the detection process. Therefore, label-free detection in free systems shows promising application prospects in high-throughput screening, point-of-care testing, and analysis of real molecular interactions.

[0005] However, signal changes caused by molecular binding in free systems are usually small, placing high demands on the sensitivity and anti-interference capabilities of the sensing system. Although traditional interferometric sensing methods can detect changes in refractive index, in practical applications, weak phase signals are often difficult to read directly and accurately, and are easily affected by environmental factors such as temperature drift and mechanical vibration, leading to decreased detection stability and repeatability.

[0006] Quantum weak measurement techniques, by constructing approximately orthogonal pre-selected and post-selected states, can amplify and detect weak signals under weak coupling conditions, thus exhibiting high sensitivity in the measurement of small phase, optical rotation, and other physical quantities. In recent years, weak measurement methods have also begun to be used in the field of label-free biomolecule detection. However, most existing weak measurement biosensing schemes are still based on fixed systems, and the recognition process relies on the surface fixation of the sensing interface, which still suffers from problems such as spatial steric hindrance, limited mass transfer, and complex detection procedures. Furthermore, existing frequency domain weak measurement detection methods are mostly based on single-point readout, and still have certain limitations in high-throughput detection and real-time dynamic detection.

[0007] Therefore, there is an urgent need to provide a weak measurement optical biosensing method and system suitable for free homogeneous systems, so as to achieve high sensitivity, low noise and real-time detection of weak signals caused by molecular interactions without the need for fixed recognition elements. Summary of the Invention

[0008] This invention proposes a method and system for analyzing free-state molecular interactions using Mach-Zehnder interference structures. It can solve the problems of steric hindrance, limited mass transfer, complex detection process, and difficulty in accurately reflecting the molecular interaction process in free systems in existing label-free detection technologies for fixed systems, as well as the problems of insufficient sensitivity of traditional interferometric detection methods to weak signals and susceptibility to environmental noise interference. It can achieve highly sensitive, real-time, and high-throughput detection of biomolecular interactions in free solution systems.

[0009] The present invention adopts the following technical solution.

[0010] This invention employs a Mach-Zehnder interferometer-based method for analyzing molecular interactions in ionized states. Based on the principle of weak measurement, this method utilizes an intensity imaging module, replacing the traditional spectrometer with an area array intensity camera, to perform high-precision, real-time, and high-throughput biomolecular interaction monitoring in a ionized system approaching real-world physiological conditions. Specifically, by constructing an improved Mach-Zehnder interferometer optical path, the minute refractive index change caused by biomolecular binding in the ionized system is transformed into a phase difference between two different polarization components of the probe light at the probe arm and reference arm. Subsequently, based on the principle of weak measurement, a weak amplification effect is introduced using near-orthogonal post-selection, converting this minute phase difference into a significant change in light intensity. Simultaneously, dual-channel differential measurement effectively reduces common-mode noise interference. This invention achieves high-precision, real-time molecular interaction monitoring in a ionized system approaching real-world physiological conditions and possesses the capability to extend to multi-channel parallel detection. It effectively overcomes the shortcomings of traditional solid-phase detection, such as kinetic bias and low throughput caused by steric hindrance and limited mass transfer due to molecular fixation. This method can be applied to fields such as new drug target screening, clinical in vitro diagnostics, and basic life science research.

[0011] The analytical method detects biomolecules in a free system, including macromolecular proteins and nucleic acids.

[0012] When it is necessary to avoid the steric hindrance and mass transfer limitations introduced by molecular fixation in order to overcome the resulting problems such as kinetic deviation and insufficient flux, the free system does not modify the probe molecules on the sensing surface of the analytical system.

[0013] The analytical method includes the following steps:

[0014] Step a: Construct an improved Mach-Zehnder interferometer optical path, which includes a detector arm and a reference arm, corresponding to two different polarization components of the detector beam, respectively;

[0015] Step b: Introduce the test solution and the corresponding buffer solution or blank control solution into the probe arm and the reference arm respectively to form the sample channel of the probe arm and the reference channel of the reference arm.

[0016] The test solution uses the buffer solution as the base solvent system and contains the analyte molecules. When used for molecular interaction detection, the test solution contains at least two analyte molecules that can interact, or contains analyte molecules that can undergo binding, dissociation, conformational change, or aggregation. When biomolecules in the test solution interact, they cause a change in the refractive index of the solution, thereby generating a phase difference change between two different polarized lights passing through the sample channel and the reference channel.

[0017] Step c: Recombine the two different polarization components that have passed through the probe arm and the reference arm, and adjust the polarization state combination and relative phase relationship of the two polarization components through the Soray-Barbiner SBC phase compensator. Then, prepare a post-selected state that is nearly orthogonal to the pre-selected state through a post-selected polarizer, so that the small phase difference caused by the change in the refractive index of the solution under test is weakly measured and amplified at the post-selected output end, and converted into a change in light intensity that can be collected by the imaging detector.

[0018] Step d: Use the light intensity imaging module to acquire two-dimensional light intensity images of the molecular binding process in real time, and use the imaging detector to record the dynamic changes in the light intensity of the output beam in real time.

[0019] Step e: Perform self-reference differential processing on the sample channel output signal using the reference channel output signal to achieve highly sensitive real-time detection of biomolecular interaction processes.

[0020] The two-dimensional light intensity image is processed to extract the average light intensity of the region of interest at the output end. The average light intensity is then combined with the initial baseline light intensity for background subtraction and quantitative analysis to achieve real-time detection of biomolecular interaction processes.

[0021] In step b, the buffer solution or blank control solution and the base solvent system of the test solution are consistent or substantially consistent with each other in at least one of the following parameters: pH, ionic strength, osmotic pressure, temperature, viscosity and initial background refractive index.

[0022] In step c, the polarization state combination and relative phase relationship of the two different polarization components are adjusted by using the SBC phase compensator so that the system operates in a linear response with high weak measurement sensitivity.

[0023] In step c, after beam combining, a post-selection state that is nearly orthogonal to the pre-selection state is prepared by the post-selection module to achieve weak measurement amplification of the phase difference change.

[0024] The image processing method in step e includes region of interest selection, average light intensity calculation, initial baseline subtraction, light intensity change extraction, and quantitative calibration based on the relationship between light intensity change and refractive index or concentration.

[0025] Background subtraction includes subtracting camera dark noise, initial baseline drift, light source intensity fluctuations, and background light intensity changes caused by liquid flow.

[0026] The analytical method uses broadband low-coherence continuous light as the incident probe light, which is generated by light-emitting diodes (LEDs) or superluminescent light-emitting diodes (SLDs), preferably light generated by SLDs in the near-infrared band.

[0027] Before the probe beam enters the probe arm and the reference arm, the incident light is pre-selected for polarization to prepare an initial polarization state as a pre-selected state; the initial polarization state is one of linear polarization, elliptic polarization, or circular polarization.

[0028] The analytical method is applicable to real-time label-free detection of molecular interactions in free systems. These molecular interactions include interactions between biomacromolecules and small molecules, interactions between biomacromolecules, interactions between small molecules, and molecular interactions in multi-component systems.

[0029] A free-state molecular interaction analysis system for Mach-Zehnder interferometer structures, used to perform the free-state molecular interaction analysis method for Mach-Zehnder interferometer structures described above, includes:

[0030] Light source module: used to generate broadband, low-coherence continuous light;

[0031] Polarization preselection module: used to polarize the broadband low-coherence continuous light to prepare a preselected state;

[0032] Interference sensing module: It adopts an improved Mach-Zehnder interferometer structure, including a front beam splitter, a probe arm, a reference arm, and a rear beam combiner. The front beam splitter is used to separate the incident light after polarization preselection into probe light and reference light according to orthogonal polarization states, and introduce them into the probe arm and reference arm respectively. The probe arm is used to introduce the test solution to form a sample channel. The reference arm is used to introduce buffer solution or blank control solution to form a reference channel. The rear beam combiner is used to re-combine the beams in the probe arm and reference arm.

[0033] Polarization phase adjustment component: used to adjust the combination of polarization states and relative phase relationship of two different polarization components, and to make the system work in the weak measurement linear response region;

[0034] Post-selection module: Used to prepare post-selection states that are nearly orthogonal to the pre-selection states in order to achieve weak measurement amplification;

[0035] Light intensity imaging module: used to acquire two-dimensional light intensity images of the output beam in real time;

[0036] Data processing module: Used to process the two-dimensional light intensity image acquired by the light intensity imaging module, extract the average light intensity or light intensity change of the region of interest at the output end, and perform background subtraction, quantitative calibration and parameter analysis;

[0037] The half-wave plate is used to rotate the polarization directions of the horizontally polarized light and the vertically polarized light output from the front beam splitter by 90°, so as to satisfy the beam combining condition of the two orthogonal polarization components in the rear beam combiner. The SBC phase compensator is used to adjust the relative phase relationship between the two polarization components after beam combining, and works with the rear selection module to realize weak measurement output.

[0038] The light intensity imaging module includes an area array camera; the area array camera is an industrial camera (11) used to acquire and select two-dimensional light intensity images at the output end in real time.

[0039] The analysis system is as follows Figure 1 As shown, the sample arm includes a superluminescent diode (1), a collimating lens (2), a front selective polarizer (3), a front cleaving beam splitter (4), and a half-wave plate (5) arranged sequentially in the light emission direction of the light source module. It also includes a sample cell or microchannel assembly, and a rear cleaving beam combiner (8), an SBC phase compensator (9), a rear selective polarizer (10), and an industrial camera (11) of the reference arm behind the assembly. The sample cell or microchannel includes a sensing channel (6) and a reference channel (7).

[0040] The light emitted by the superluminescent diode is collimated by a collimating lens, and then pre-selected into a specific polarization state by a front polarizer. It is then split into a horizontally polarized measurement light and a vertically polarized reference light by a front beam splitter (3). The two beams are modulated by a half-wave plate and then pass through the sensing channel and the reference channel, respectively.

[0041] The measurement light from the sensing channel and the reference light from the reference channel are first recombined and interfered by a rear beam combiner, then the output is selected by a weak measurement enhancement module consisting of an SBC phase compensator and a post-selection polarizer. Finally, an industrial camera acquires a two-dimensional light intensity image of the output beam and its dynamic changes.

[0042] The analytical system's sample analysis process includes the following steps:

[0043] Step 1: Establish a dual-polarization component interferometric sensing optical path;

[0044] Broadband low-coherence continuous light is collimated and then fed into a polarization pre-selection module to form a preset pre-selected polarization state. Subsequently, a pre-splitter and a half-wave plate decompose the incident light into two spatially separated beams with different polarization states. One beam serves as the probe light entering the sensing channel, and the other serves as the reference light entering the reference channel. A free-state test solution containing the analyte molecules is introduced into the sensing channel, while a buffer solution or blank control solution corresponding to the test solution is introduced into the reference channel. Preferably, the test solution uses the buffer solution in the reference channel as the base solvent system, with one or more additives. The test solution contains a target molecule; the buffer solution or blank control solution and the test solution are kept consistent or substantially consistent in terms of pH, ionic strength, osmotic pressure, temperature, viscosity and initial background refractive index, so that the reference channel can reflect the common-mode background changes caused by light source fluctuations, ambient temperature drift, mechanical vibration and fluid disturbance; the main difference between the test solution and the buffer solution or blank control solution is that the test solution contains a component that can interact with the target molecule, while the buffer solution or blank control solution does not contain the target interacting component, or contains a control component that does not interact specifically.

[0045] Step two: Convert the refractive index change caused by molecular interactions into a phase difference change;

[0046] When two or more biomolecules in the test solution combine, dissociate, or undergo conformational changes within the sensing channel, the overall refractive index or local effective refractive index of the solution undergoes a slight change. Since the probe light passes through the sensing channel and the reference light passes through the reference channel, the two beams of light acquire different optical path changes during propagation, thus forming a phase difference change related to molecular interactions when they are recombined.

[0047] Step 3: Adjust the polarization phase adjustment component to bring the system into the weak measurement linear response region;

[0048] Before formal testing, buffer solutions are introduced into the sensing channel and the reference channel respectively to bring the two channels to baseline. By using the SBC phase compensator to adjust the polarization state combination and relative phase relationship of the two different polarization components, the system output is made to be in the working range that is sensitive to small phase perturbations. Preferably, the post-selection polarizer is used to adjust the post-selection state to a state that is close to orthogonal but not completely orthogonal to the pre-selection state, so that the system can produce a weak amplification effect while maintaining sufficient output light intensity, which is convenient for stable acquisition by the area array camera.

[0049] Step four: After weak measurement, select to convert the small phase difference into a change in light intensity;

[0050] The two beams of light propagating through the sensing channel and the reference channel are re-combined by a post-beam combiner. The combined light then passes through an SBC phase compensator and a post-selected polarizer. The SBC phase compensator is used to adjust the relative phase relationship between the two different polarization components, and the post-selected polarizer is used to prepare a post-selected state that is nearly orthogonal to the pre-selected state. Since the post-selected state is nearly orthogonal to the pre-selected state, the tiny phase difference introduced by molecular interactions in the sensing channel will be amplified as a change in light intensity at the post-selected output. Therefore, the tiny changes in refractive index and phase that are originally difficult to read directly are converted into a two-dimensional light intensity change signal that can be recorded by the camera in real time.

[0051] Step 5: Acquire two-dimensional light intensity images in real time and extract response curves;

[0052] Two-dimensional light intensity images are continuously acquired using an area array camera and then selected for output. For each frame of the image, a sensing area and a reference area are selected respectively, and the average light intensity, total light intensity or other characterization values ​​of the corresponding areas are calculated to obtain the light intensity variation curves of the sensing channel and the reference channel over time.

[0053] Step six: Extract light intensity signals and subtract background;

[0054] The output signal of the sensing channel is differentially processed with the output signal of the reference channel to obtain the net response signal. Specifically, the initial baseline light intensity under buffer conditions can be recorded first, and then the light intensity changes of the sensing channel and the reference channel relative to the baseline can be calculated separately. Finally, the weighted difference is performed according to the response ratio of the two channels to obtain the net light intensity change caused by molecular interaction. This processing method can deduct common-mode noise such as light source power fluctuations, ambient temperature drift, mechanical vibration, liquid flow rate fluctuations, and camera background drift.

[0055] Step 7: Establish calibration relationships and perform interaction analysis;

[0056] Before detecting an unknown sample, a standard solution with a known refractive index or concentration can be sequentially introduced into the sensing channel, and the light intensity changes in the sensing channel and the reference channel can be collected simultaneously. After differential processing, a calibration curve is established with the refractive index change or sample concentration as the abscissa and the net light intensity change as the ordinate. During actual detection, the refractive index change, concentration change, or interaction response intensity of the sample to be tested can be deduced from the net light intensity change generated by the sample, combined with the calibration curve. Furthermore, the dynamic process of molecular binding and dissociation can be analyzed based on the rise, stabilization, and fall of the net light intensity response over time.

[0057] This invention utilizes the principle of weak measurement to convert the refractive index / phase changes introduced by molecular binding into changes in light intensity. It employs an area array light intensity camera to replace traditional spectrometers, achieving high-throughput biomolecule detection. The detection targets are biomolecules in a free system, including macromolecular proteins and nucleic acids. Compared to immobilized detection methods that modify the sensing surface with probe molecules, the free system in this invention does not require surface modification, thus effectively avoiding the steric hindrance and mass transfer limitations introduced by molecular immobilization, thereby overcoming problems such as kinetic deviations and insufficient throughput.

[0058] This invention provides a method for analyzing molecular interactions in ionized states based on the weak measurement principle and a Mach-Zehnder interferometer structure. This method constructs an improved Mach-Zehnder interferometer optical path to convert the minute refractive index change caused by biomolecule binding in the ionized system into a phase difference between two different polarization components of the probe light. Then, based on the weak measurement principle, a weak amplification effect is introduced using near-orthogonal post-selection, transforming this minute phase difference into a significant change in light intensity. Simultaneously, dual-channel differential measurement effectively reduces common-mode noise interference. This invention achieves high-precision, real-time molecular interaction monitoring in a ionized system close to a real physiological environment and has the capability to be extended to multi-channel parallel detection, effectively overcoming the shortcomings of traditional solid-phase detection, such as kinetic bias and low throughput caused by steric hindrance and limited mass transfer due to molecular fixation. This method can be applied to fields such as new drug target screening, clinical in vitro diagnostics, and basic life science research.

[0059] The present invention also has the following advantages:

[0060] 1) High sensitivity and high detection stability: The system improves the detection sensitivity to weak molecular interaction signals through a weak value amplification mechanism. At the same time, combined with the Mach-Zehnder self-differential structure, it can cancel background noise caused by environmental temperature drift, liquid flow rate fluctuations and mechanical vibrations in real time, ensuring the system's excellent stability in clinical complex matrix detection.

[0061] 2) Label-free real-time imaging analysis: This system breaks through the dependence of traditional sensors on surface fixation, realizing in-situ monitoring of free systems in non-fixed solutions. No fluorescent label is required, providing a visualization tool for studying molecular interactions.

[0062] 3) Potential for applications in multiple fields: This method has broad applicability to the detection of targets such as proteins, nucleic acids and small molecules. It is expected to be applied to fields such as early disease diagnosis, high-throughput drug screening and environmental toxicology monitoring, and lays the technical foundation for the development of domestically produced high-end molecular interaction analysis instruments with independent intellectual property rights. Attached Figure Description

[0063] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0064] Appendix Figure 1 This is a schematic diagram of the analysis system structure in an embodiment of the present invention;

[0065] Appendix Figure 2 This is a schematic diagram of the analysis system module in an embodiment of the present invention;

[0066] In the figure: Superluminescent diode (1), collimating lens (2), front selective polarizer (3), front calcite beam splitter (4), half-wave plate (5), sensing channel at the sample arm (6), reference channel at the reference arm (7), rear calcite beam combiner (8), SBC phase compensator (9), rear selective polarizer (10), industrial camera (11). Detailed Implementation

[0067] The technical solution of the present invention will be further described below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following embodiments.

[0068] As shown in the figure, the free-state molecular interaction analysis method using a Mach-Zehnder interferometer is based on the weak measurement principle. This method, in a free system approaching a real physiological environment, utilizes an intensity imaging module, replacing the traditional spectrometer with an area array intensity camera to perform high-precision, real-time, and high-throughput biomolecular interaction monitoring. Specifically, by constructing an improved Mach-Zehnder interferometer optical path, the minute refractive index change caused by biomolecular binding in the free system is converted into a phase difference between two different polarization components of the probe light at the probe arm and reference arm. Subsequently, based on the weak measurement principle, a weak amplification effect is introduced using near-orthogonal post-selection, transforming this minute phase difference into a significant light intensity change. Simultaneously, dual-channel differential measurement effectively reduces common-mode noise interference. This invention achieves high-precision, real-time molecular interaction monitoring in a free system approaching a real physiological environment and has the capability to extend to multi-channel parallel detection, effectively overcoming the shortcomings of traditional solid-phase detection, such as kinetic deviations and low throughput caused by steric hindrance and limited mass transfer due to molecular fixation. This method can be applied to fields such as new drug target screening, clinical in vitro diagnostics, and basic life science research.

[0069] The analytical method detects biomolecules in a free system, including macromolecular proteins and nucleic acids.

[0070] When it is necessary to avoid the steric hindrance and mass transfer limitations introduced by molecular fixation in order to overcome the resulting problems such as kinetic deviation and insufficient flux, the free system does not modify the probe molecules on the sensing surface of the analytical system.

[0071] The analytical method includes the following steps:

[0072] Step a: Construct an improved Mach-Zehnder interferometer optical path, which includes a detector arm and a reference arm, corresponding to two different polarization components of the detector beam, respectively;

[0073] Step b: Introduce the test solution and the corresponding buffer solution or blank control solution into the probe arm and the reference arm respectively to form the sample channel of the probe arm and the reference channel of the reference arm.

[0074] The test solution uses the buffer solution as the base solvent system and contains the analyte molecules. When used for molecular interaction detection, the test solution contains at least two analyte molecules that can interact, or contains analyte molecules that can undergo binding, dissociation, conformational change, or aggregation. When biomolecules in the test solution interact, they cause a change in the refractive index of the solution, thereby generating a phase difference change between two different polarized lights passing through the sample channel and the reference channel.

[0075] Step c: Recombine the two different polarization components that have passed through the probe arm and the reference arm, and adjust the polarization state combination and relative phase relationship of the two polarization components through the Soray-Barbijne SBC phase compensator (SBC phase compensator). Then, prepare a post-selected state that is nearly orthogonal to the pre-selected state through a post-selected polarizer, so that the small phase difference caused by the change in the refractive index of the test solution is weakly measured and amplified at the post-selected output end, and converted into a change in light intensity that can be collected by the imaging detector.

[0076] Step d: Use the light intensity imaging module to acquire two-dimensional light intensity images of the molecular binding process in real time, and use the imaging detector to record the dynamic changes in the light intensity of the output beam in real time.

[0077] Step e: Perform self-reference differential processing on the sample channel output signal using the reference channel output signal to achieve highly sensitive real-time detection of biomolecular interaction processes.

[0078] The two-dimensional light intensity image is processed to extract the average light intensity of the region of interest at the output end. The average light intensity is then combined with the initial baseline light intensity for background subtraction and quantitative analysis to achieve real-time detection of biomolecular interaction processes.

[0079] In step b, the buffer solution or blank control solution and the base solvent system of the test solution are consistent or substantially consistent with each other in at least one of the following parameters: pH, ionic strength, osmotic pressure, temperature, viscosity and initial background refractive index.

[0080] In step c, the polarization state combination and relative phase relationship of the two different polarization components are adjusted by using the SBC phase compensator so that the system operates in a linear response with high weak measurement sensitivity.

[0081] In step c, after beam combining, a post-selection state that is nearly orthogonal to the pre-selection state is prepared by the post-selection module to achieve weak measurement amplification of the phase difference change.

[0082] The image processing method in step e includes region of interest selection, average light intensity calculation, initial baseline subtraction, light intensity change extraction, and quantitative calibration based on the relationship between light intensity change and refractive index or concentration.

[0083] Background subtraction includes subtracting camera dark noise, initial baseline drift, light source intensity fluctuations, and background light intensity changes caused by liquid flow.

[0084] The analysis method uses broadband low-coherence continuous light as the incident probe light, which is generated by light-emitting diode (LED) or superluminescent light-emitting diode (SLD), preferably light generated by a superluminescent light-emitting diode in the near-infrared band.

[0085] Before the probe beam enters the probe arm and the reference arm, the incident light is pre-selected for polarization to prepare an initial polarization state as a pre-selected state; the initial polarization state is one of linear polarization, elliptic polarization, or circular polarization.

[0086] The analytical method is applicable to real-time label-free detection of molecular interactions in free systems. These molecular interactions include interactions between biomacromolecules and small molecules, interactions between biomacromolecules, interactions between small molecules, and molecular interactions in multi-component systems.

[0087] A free-state molecular interaction analysis system for Mach-Zehnder interferometer structures, used to perform the free-state molecular interaction analysis method for Mach-Zehnder interferometer structures described above, includes:

[0088] Light source module: used to generate broadband, low-coherence continuous light;

[0089] Polarization preselection module: used to polarize the broadband low-coherence continuous light to prepare a preselected state;

[0090] Interference sensing module: It adopts an improved Mach-Zehnder interferometer structure, including a front beam splitter, a probe arm, a reference arm, and a rear beam combiner. The front beam splitter is used to separate the incident light after polarization preselection into probe light and reference light according to orthogonal polarization states, and introduce them into the probe arm and reference arm respectively. The probe arm is used to introduce the test solution to form a sample channel. The reference arm is used to introduce buffer solution or blank control solution to form a reference channel. The rear beam combiner is used to re-combine the beams in the probe arm and reference arm.

[0091] Polarization phase adjustment component: used to adjust the relative phase relationship between two different polarization components and to make the system operate in the weak measurement linear response region;

[0092] Post-selection module: Used to prepare post-selection states that are nearly orthogonal to the pre-selection states in order to achieve weak measurement amplification;

[0093] Light intensity imaging module: used to acquire two-dimensional light intensity images of the output beam in real time;

[0094] Data processing module: Used to process the two-dimensional light intensity image acquired by the light intensity imaging module, extract the average light intensity or light intensity change of the region of interest at the output end, and perform background subtraction, quantitative calibration and parameter analysis;

[0095] The half-wave plate is used to rotate the polarization directions of the horizontally polarized light and the vertically polarized light output from the front beam splitter by 90°, so as to satisfy the beam combining condition of the two orthogonal polarization components in the rear beam combiner. The SBC phase compensator is used to adjust the relative phase relationship between the two polarization components after beam combining, and works with the rear selection module to realize weak measurement output.

[0096] The light intensity imaging module includes an area array camera; the area array camera is an industrial camera (11) used to acquire and select two-dimensional light intensity images at the output end in real time.

[0097] The analysis system is as follows Figure 1 As shown, the sample arm includes a superluminescent diode (1), a collimating lens (2), a front selective polarizer (3), a front cleaving beam splitter (4), and a half-wave plate (5) arranged sequentially in the light emission direction of the light source module. It also includes a sample cell or microchannel assembly, and a rear cleaving beam combiner (8), an SBC phase compensator (9), a rear selective polarizer (10), and an industrial camera (11) of the reference arm behind the assembly. The sample cell or microchannel includes a sensing channel (6) and a reference channel (7).

[0098] The light emitted by the superluminescent diode is collimated by a collimating lens, and then pre-selected into a specific polarization state by a front polarizer. It is then split into a horizontally polarized measurement light and a vertically polarized reference light by a front beam splitter (3). The two beams are modulated by a half-wave plate and then pass through the sensing channel and the reference channel, respectively.

[0099] The measurement light from the sensing channel and the reference light from the reference channel are first recombined and interfered by a rear beam combiner, then the output is selected by a weak measurement enhancement module consisting of an SBC phase compensator and a post-selection polarizer. Finally, an industrial camera acquires a two-dimensional light intensity image of the output beam and its dynamic changes.

[0100] The analytical system's sample analysis process includes the following steps:

[0101] Step 1: Establish a dual-polarization component interferometric sensing optical path;

[0102] Broadband low-coherence continuous light is collimated and then fed into a polarization pre-selection module to form a preset pre-selected polarization state. Subsequently, a pre-splitter and a half-wave plate decompose the incident light into two spatially separated beams with different polarization states. One beam serves as the probe light entering the sensing channel, and the other serves as the reference light entering the reference channel. A free-state test solution containing the analyte molecules is introduced into the sensing channel, while a buffer solution or blank control solution corresponding to the test solution is introduced into the reference channel. Preferably, the test solution uses the buffer solution in the reference channel as the base solvent system, with one or more additives. The test solution contains a target molecule; the buffer solution or blank control solution and the test solution are kept consistent or substantially consistent in terms of pH, ionic strength, osmotic pressure, temperature, viscosity and initial background refractive index, so that the reference channel can reflect the common-mode background changes caused by light source fluctuations, ambient temperature drift, mechanical vibration and fluid disturbance; the main difference between the test solution and the buffer solution or blank control solution is that the test solution contains a component that can interact with the target molecule, while the buffer solution or blank control solution does not contain the target interacting component, or contains a control component that does not interact specifically.

[0103] Step two: Convert the refractive index change caused by molecular interactions into a phase difference change;

[0104] When two or more biomolecules in the test solution combine, dissociate, or undergo conformational changes within the sensing channel, the overall refractive index or local effective refractive index of the solution undergoes a slight change. Since the probe light passes through the sensing channel and the reference light passes through the reference channel, the two beams of light acquire different optical path changes during propagation, thus forming a phase difference change related to molecular interactions when they are recombined.

[0105] Step 3: Adjust the polarization phase adjustment component to bring the system into the weak measurement linear response region;

[0106] Before formal testing, buffer solutions are introduced into the sensing channel and the reference channel respectively to bring the two channels to baseline. By using the SBC phase compensator to adjust the polarization state combination and relative phase relationship of the two different polarization components, the system output is made to be in the working range that is sensitive to small phase perturbations. Preferably, the post-selection polarizer is used to adjust the post-selection state to a state that is close to orthogonal but not completely orthogonal to the pre-selection state, so that the system can produce a weak amplification effect while maintaining sufficient output light intensity, which is convenient for stable acquisition by the area array camera.

[0107] Step four: After weak measurement, select to convert the small phase difference into a change in light intensity;

[0108] The two beams of light propagating through the sensing channel and the reference channel are re-combined by a post-beam combiner. The combined light then passes through an SBC phase compensator and a post-selected polarizer. The SBC phase compensator is used to adjust the relative phase relationship between the two different polarization components, and the post-selected polarizer is used to prepare a post-selected state that is nearly orthogonal to the pre-selected state. Since the post-selected state is nearly orthogonal to the pre-selected state, the tiny phase difference introduced by molecular interactions in the sensing channel will be amplified as a change in light intensity at the post-selected output. Therefore, the tiny changes in refractive index and phase that are originally difficult to read directly are converted into a two-dimensional light intensity change signal that can be recorded by the camera in real time.

[0109] Step 5: Acquire two-dimensional light intensity images in real time and extract response curves;

[0110] Two-dimensional light intensity images are continuously acquired using an area array camera and then selected for output. For each frame of the image, a sensing area and a reference area are selected respectively, and the average light intensity, total light intensity or other characterization values ​​of the corresponding areas are calculated to obtain the light intensity variation curves of the sensing channel and the reference channel over time.

[0111] Step six: Extract light intensity signals and subtract background;

[0112] The output signal of the sensing channel is differentially processed with the output signal of the reference channel to obtain the net response signal. Specifically, the initial baseline light intensity under buffer conditions can be recorded first, and then the light intensity changes of the sensing channel and the reference channel relative to the baseline can be calculated separately. Finally, the weighted difference is performed according to the response ratio of the two channels to obtain the net light intensity change caused by molecular interaction. This processing method can deduct common-mode noise such as light source power fluctuations, ambient temperature drift, mechanical vibration, liquid flow rate fluctuations, and camera background drift.

[0113] Step 7: Establish calibration relationships and perform interaction analysis;

[0114] Before detecting an unknown sample, a standard solution with a known refractive index or concentration can be sequentially introduced into the sensing channel, and the light intensity changes in the sensing channel and the reference channel can be collected simultaneously. After differential processing, a calibration curve is established with the refractive index change or sample concentration as the abscissa and the net light intensity change as the ordinate. During actual detection, the refractive index change, concentration change, or interaction response intensity of the sample to be tested can be deduced from the net light intensity change generated by the sample, combined with the calibration curve. Furthermore, the dynamic process of molecular binding and dissociation can be analyzed based on the rise, stabilization, and fall of the net light intensity response over time.

[0115] Example 1:

[0116] A free-state molecular interaction analysis system based on the weak measurement principle Mach-Zehnder interferometer structure, such as Figure 1As shown, it includes a superluminescent diode 1, a collimating lens 2, a front selective polarizer 3, a front calcite beam splitter 4, a half-wave plate 5, a sample cell or microchannel, a rear calcite beam combiner 8, an SBC phase compensator 9, a rear selective polarizer 10, and an industrial camera 11; wherein, the sample cell or microchannel includes a sensing channel 6 and a reference channel 7.

[0117] The light emitted by the superluminescent diode 1 is collimated by the collimating lens 2, pre-selected to a specific polarization state by the pre-selective polarizer 3, and then split into a horizontally polarized measurement beam and a vertically polarized reference beam by the front calcite beam splitter 4. The two beams are modulated by the half-wave plate 5 and pass through the sensing channel 6 and the reference channel 7, respectively. The measurement beam passing through the sensing channel 6 and the reference beam passing through the reference channel 7 are re-combined by another rear calcite beam combiner 8, and then post-selected by a weak measurement enhancement module consisting of the SBC phase compensator 9 and the rear-selective polarizer 10. Finally, the industrial camera 11 acquires a two-dimensional light intensity image of the output beam and its dynamic changes.

[0118] In this embodiment, the target of the free molecular interaction detection is the specific binding process between protein A and mouse immunoglobulin G (mouse IgG). In this embodiment, the test solution and the reference channel buffer use the same basic buffer system. The basic buffer system can be phosphate-buffered saline (PBS), Tris-HCl buffer, HEPES buffer, physiological saline buffer, or other aqueous buffer systems suitable for maintaining the activity of biomolecules. The pH, salt concentration, and ionic composition of the basic buffer system can be adjusted according to the stability and binding conditions of the analyte molecule, and auxiliary components such as surfactants, stabilizers, or preservatives can be selectively added. The buffer or blank control solution in the reference channel is kept consistent or substantially consistent with the test solution in terms of the basic buffer system, pH, ionic strength, and temperature conditions to reduce non-specific light intensity changes caused by solvent background differences. For example, in the detection of the interaction between protein A and mouse IgG, the test solution in sensing channel 6 can be the same basal buffer containing both protein A and mouse IgG; the buffer in reference channel 7 can be the same basal buffer without protein A and mouse IgG, or a blank control solution containing only protein A, only mouse IgG, or a control molecule that does not specifically bind. By making the reference channel and sensing channel have the same or substantially the same basal solvent background, non-specific signals caused by differences in the buffer system can be reduced, and the accuracy of dual-channel differential processing can be improved. Neither protein A nor mouse IgG is pre-fixed to a solid surface but remains in a free-diffusion state in the solution and interacts within the sensing channel.

[0119] After the system is built, buffer solution is first synchronously injected into sensing channel 6 and reference channel 7 to bring the system to baseline. Then, the relative phase relationship between the two different polarization components is adjusted using an SBC phase compensator, and a post-selection polarizer 10 is used to ensure that the post-selection state and the pre-selection state are nearly orthogonal. Through these adjustments, the system output is positioned in a linear operating region that is highly sensitive to small changes in refractive index. After the flow field stabilizes, the initial baseline light intensity is recorded. During image processing, the industrial camera continuously acquires image sequences from the post-selection output. For each frame, the region of interest corresponding to the post-selection output is selected, and the average light intensity of that region is calculated. Let the average light intensity at time t be I(t), and the average light intensity in the baseline state be I0. Then, the change in light intensity can be expressed as ΔI(t) = I(t) − I0. The obtained ΔI(t) can be used as the light intensity response signal caused by molecular interactions to characterize the molecular interaction process in the sensing channel.

[0120] The net interaction response signal can be used to qualitatively determine whether interactions or specific bindings occur between molecules, or it can be used for quantitative analysis in conjunction with standard solution calibration curves. When the steady-state amplitude of ΔIdiff(t) generated by samples of different concentrations is linearly related to the concentration or refractive index change, the system sensitivity can be obtained through linear fitting. When it is necessary to analyze the dynamic process of molecular binding or dissociation, the rise rate, response amplitude, steady-state signal, and dissociation phase change trend of the response curve can be further extracted to characterize the strength of interactions between different molecular systems.

[0121] (1) System calibration and sensitivity acquisition

[0122] During the system calibration phase, a series of standard solutions with known concentration gradients are sequentially injected into sensing channel 6, and the steady-state changes in the output light intensity of sensing channel 6 and reference channel 7 are recorded simultaneously. Preferably, a buffer solution or blank control solution corresponding to the standard solution is injected into reference channel 7. By performing region of interest extraction, baseline subtraction, and background correction on the light intensity image at the selected output end, the light intensity changes corresponding to different standard solutions are obtained.

[0123] Furthermore, a linear fit is performed with the refractive index unit (RIU) or standard solution concentration as the abscissa and the net light intensity change as the ordinate to establish a calibration curve of light intensity change versus refractive index or concentration. This calibration curve can be used to obtain the system sensitivity and verify the system's linear response characteristics within the target detection range.

[0124] (2) Detection of the interaction between protein A and mouse IgG free state

[0125] In the actual detection process, a mixed sample containing protein A and mouse IgG is injected into sensing channel 6, while a corresponding buffer solution or a control solution without the binding component is injected into reference channel 7. Protein A and mouse IgG remain in a free-diffusion state within sensing channel 6 and undergo specific binding. This binding process causes minute changes in the local volume refractive index and optical phase, resulting in dynamic changes in the system's output light intensity. These minute changes are amplified by weak measurement and then captured and recorded by industrial camera 11.

[0126] By processing the image sequence acquired by the industrial camera 11 in real time and combining it with the synchronous differential operation between the sensing channel 6 and the reference channel 7, a response curve of net light intensity changing over time can be obtained. Based on this response curve, the binding process of protein A to mouse IgG in its free state can be monitored in real time, and further quantitative analysis of sample concentration changes or interaction response intensity can be performed by combining it with the calibration curve.

[0127] (3) Detection methods under different concentration conditions

[0128] In another embodiment, the concentration of mouse IgG can be kept constant while the concentration of protein A can be varied; or the concentration of protein A can be kept constant while the concentration of mouse IgG can be varied. Test sample solutions with different concentration gradients are prepared and sequentially injected into sensing channel 6. By comparing the net light intensity response amplitude and its dynamic change curves obtained under different concentration conditions, the response law of the interaction between protein A and mouse IgG can be established, providing a basis for subsequent quantitative concentration analysis and interaction parameter extraction.

[0129] (4) Comparison with the implementation method

[0130] To verify the system's response to specific molecular interactions in the free state, the following control experiment can be further set up:

[0131] Inject only protein A solution into sensing channel 6, and inject the corresponding buffer solution into reference channel 7;

[0132] Mouse IgG solution was injected into sensing channel 6, and the corresponding buffer solution was injected into reference channel 7.

[0133] A mixture of protein A and mouse IgG was injected into sensing channel 6, and the corresponding buffer solution was injected into reference channel 7.

[0134] The protein A solution, mouse IgG solution, mixed solution of protein A and mouse IgG, and the corresponding buffer in the reference channel all use the same or substantially the same basic buffer system.

[0135] By comparing the differential output responses under the above different conditions, the background refractive index change caused by a single component can be distinguished from the net response signal caused by the specific binding of protein A and mouse IgG, thereby verifying the effectiveness of the method of the present invention in the detection of free molecular interactions.

[0136] Furthermore, those skilled in the art will understand that, without departing from the core concept of the present invention, the detection targets in the sensing channel are not limited to protein A and mouse IgG, but can be replaced with other types of protein-protein, protein-small molecule or multi-component systems, all of which should fall within the protection scope of the present invention.

[0137] Example 2:

[0138] The system used in this example includes: an 830nm center wavelength superluminescent diode, a calcite beam splitter (front beam splitter and back beam combiner), polarizers (front selector and back selector), a half-wave plate, an SBC phase compensator, an integrated dual-channel microfluidic chip, an industrial camera, a syringe pump, a computer and data acquisition and control software, an optomechanical adjustment frame, an optical platform, and a light shield.

[0139] In one embodiment of the present invention, the center wavelength of the superluminescent diode is 830 nm, the spectral bandwidth is 50 nm, and the output power is 10 mW.

[0140] In one embodiment of the present invention, the calcite beam splitter is a broadband birefringent beam splitting crystal with an effective working wavelength covering 650-1100nm and an extinction ratio better than 1000:1, which can separate the incident light into two parallel beams with a spatial spacing of 4.0mm according to the orthogonal polarization state.

[0141] In one embodiment of the present invention, the polarizer operates in the near-infrared band and has an extinction ratio higher than 100,000:1, which is used to construct accurate polarization pre-selection and post-selection states.

[0142] In this example, the integrated dual-channel microfluidic chip is made of photosensitive resin and includes mutually isolated sensing channels and reference channels. The channel cross-sectional dimensions are 1mm × 1mm and the length is 40mm.

[0143] In this example, the industrial imaging camera has a resolution of 3008×3008 and a readout noise of 1.0e to 3.8e.

[0144] The above are preferred embodiments of the present invention. Any changes made to the technical solution of the present invention that do not exceed the scope of the technical solution of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for analyzing the interaction of free-state molecules in Mach-Zehnder interferometer structures, based on the weak measurement principle, characterized by: The method described above uses a light intensity imaging module to perform molecular interaction monitoring in an ionized system. Specifically, it uses a Mach-Zehnder interferometer to convert the minute refractive index change caused by the binding of biomolecules in the ionized system into a phase difference between two different polarization components of the probe light at the probe arm and the reference arm. Then, it uses near-orthogonal post-selection to introduce a weak amplification effect to convert the phase difference into a change in light intensity, and reduces system noise interference through baseline correction and background subtraction.

2. The method for analyzing the interaction of free-state molecules in Mach-Zehnder interference structures according to claim 1, characterized in that: The analytical method detects biomolecules in a free system, including macromolecular proteins and nucleic acids. When it is necessary to avoid the problems of steric hindrance and mass transfer limitation caused by molecular fixation, the probe molecules are not modified on the sensing surface of the analytical system in the free system environment setting of the analytical method.

3. The method for analyzing free-state molecular interactions in Mach-Zehnder interference structures according to claim 1, characterized in that: The analytical method includes the following steps: Step a: Construct a Mach-Zehnder interferometer optical path, which includes a detector arm and a reference arm, corresponding to two different polarization components of the detector beam, respectively; Step b: Introduce the test solution and the corresponding buffer solution or blank control solution into the probe arm and the reference arm respectively to form the sample channel of the probe arm and the reference channel of the reference arm. The test solution uses the buffer solution as the base solvent system and contains the analyte molecules. When used for molecular interaction detection, the test solution contains at least two analyte molecules that can interact, or contains analyte molecules that can undergo binding, dissociation, conformational change, or aggregation. When biomolecules in the test solution interact, they cause a change in the refractive index of the solution, thereby generating a phase difference change between two different polarized lights passing through the sample channel and the reference channel. Step c: Recombine the two different polarization components that have passed through the probe arm and the reference arm, and adjust the polarization state combination and relative phase relationship of the two polarization components through the Soray-Barbiner SBC phase compensator. Then, prepare a post-selected state that is nearly orthogonal to the pre-selected state through a post-selected polarizer, so that the small phase difference caused by the change in the refractive index of the solution under test is weakly measured and amplified at the post-selected output end, and converted into a change in light intensity that can be collected by the imaging detector. Step d: Use the light intensity imaging module to acquire two-dimensional light intensity images of the molecular binding process in real time, and use the imaging detector to record the dynamic changes in the light intensity of the output beam in real time. Step e: Perform image processing on the two-dimensional light intensity image, extract the average light intensity of the region of interest at the output end, and combine it with the initial baseline light intensity to perform background subtraction and quantitative analysis, so as to realize real-time detection of biomolecular interaction processes.

4. The method for analyzing free-state molecular interactions in Mach-Zehnder interference structures according to claim 3, characterized in that: In step b, the buffer solution or blank control solution and the base solvent system of the test solution are consistent or substantially consistent with each other in at least one of the following parameters: pH, ionic strength, osmotic pressure, temperature, viscosity and initial background refractive index.

5. The method for analyzing free-state molecular interactions in Mach-Zehnder interference structures according to claim 3, characterized in that: In step c, the polarization state combination and relative phase relationship of the two different polarization components are adjusted by using the SBC phase compensator so that the system operates in a linear response with high weak measurement sensitivity. In step c, after beam combining, a post-selection state that is nearly orthogonal to the pre-selection state is prepared by the post-selection module to achieve weak measurement amplification of the phase difference change.

6. The method for analyzing free-state molecular interactions in Mach-Zehnder interference structures according to claim 3, characterized in that: The image processing method in step e includes region of interest selection, average light intensity calculation, initial baseline subtraction, light intensity change extraction, and quantitative calibration based on the relationship between light intensity change and refractive index or concentration.

7. The method for analyzing free-state molecular interactions in Mach-Zehnder interference structures according to claim 6, characterized in that: Background subtraction includes subtracting camera dark noise, initial baseline drift, light source intensity fluctuations, and background light intensity changes caused by liquid flow.

8. The method for analyzing free-state molecular interactions in Mach-Zehnder interference structures according to claim 3, characterized in that: The analytical method uses broadband low-coherence continuous light as the incident probe light, which is generated by a light-emitting diode (LED) or a superluminescent light-emitting diode (1). Before the probe beam enters the probe arm and the reference arm, the incident light is pre-selected for polarization to prepare an initial polarization state as a pre-selected state; the initial polarization state is one of linear polarization, elliptic polarization, or circular polarization.

9. The method for analyzing free-state molecular interactions in Mach-Zehnder interference structures according to claim 3, characterized in that: The analytical method is used for real-time label-free detection of molecular interactions in free systems, including interactions between biomacromolecules and small molecules, interactions between biomacromolecules, interactions between small molecules, and molecular interactions in multi-component systems.

10. A system for analyzing the interaction of free-state molecules in Mach-Zehnder interferometer structures, used to perform the method for analyzing the interaction of free-state molecules in Mach-Zehnder interferometer structures as described in any one of claims 1, 2, 3, 4, 5, 6, 7, 8, and 9, characterized in that: The analysis system includes: Light source module: used to generate broadband, low-coherence continuous light; Polarization preselection module: used to polarize the broadband low-coherence continuous light to prepare a preselected state; Interference sensing module: It adopts an improved Mach-Zehnder interferometer structure, including a front beam splitter, a probe arm, a reference arm, and a rear beam combiner. The front beam splitter is used to separate the incident light after polarization preselection into probe light and reference light according to orthogonal polarization states, and introduce them into the probe arm and reference arm respectively. The probe arm is used to introduce the test solution to form a sample channel. The reference arm is used to introduce buffer solution or blank control solution to form a reference channel. The rear beam combiner is used to re-combine the beams in the probe arm and reference arm. Polarization phase adjustment component: used to adjust the combination of polarization states and relative phase relationship of two different polarization components, and to make the system work in the weak measurement linear response region; Post-selection module: Used to prepare post-selection states that are nearly orthogonal to the pre-selection states in order to achieve weak measurement amplification; Light intensity imaging module: used to acquire two-dimensional light intensity images of the output beam in real time; Data processing module: Used to process the two-dimensional light intensity image acquired by the light intensity imaging module, extract the average light intensity or light intensity change of the region of interest at the output end, and perform background subtraction, quantitative calibration and parameter analysis; The analysis system includes a superluminescent diode (1), a collimating lens (2), a front selective polarizer (3), a front cleaving beam splitter (4), and a half-wave plate (5) arranged sequentially in the light emission direction of the light source module. It also includes a sample cell or microchannel assembly, and a rear cleaving beam combiner (8), an SBC phase compensator (9), a rear selective polarizer (10), and an industrial camera (11) of the reference arm behind the assembly. The sample cell or microchannel includes a sensing channel (6) and a reference channel (7). The half-wave plate is used to rotate the polarization directions of the horizontally polarized light and the vertically polarized light output from the front beam splitter by 90°, so as to satisfy the beam combining condition of the two orthogonal polarization components in the rear beam combiner. The SBC phase compensator is used to adjust the relative phase relationship between the two polarization components after beam combining, and works with the rear selection module to realize weak measurement output. The light intensity imaging module includes an area array camera; the area array camera is used to acquire and select two-dimensional light intensity images at the output end in real time. The light emitted by the superluminescent diode is collimated by a collimating lens, and then pre-selected into a specific polarization state by a front polarizer. It is then split into a horizontally polarized measurement light and a vertically polarized reference light by a front beam splitter (3). The two beams are modulated by a half-wave plate and then pass through the sensing channel and the reference channel, respectively. The measurement light from the sensing channel and the reference light from the reference channel are first recombined and interfered by the rear beam combiner, and then the weak measurement enhancement module composed of the SBC phase compensator and the post-selection polarizer is used for post-selection output. Then, the industrial camera collects data on the two-dimensional light intensity image of the output beam and its dynamic changes. The analytical system's sample analysis process includes the following steps: Step 1: Establish a dual-polarization component interferometric sensing optical path; Broadband low-coherence continuous light is collimated and then fed into a polarization pre-selection module to form a preset pre-selected polarization state. Subsequently, a pre-splitter and a half-wave plate decompose the incident light into two spatially separated beams with different polarization states. One beam serves as the probe light entering the sensing channel, and the other serves as the reference light entering the reference channel. A free-state test solution containing the analyte molecules is introduced into the sensing channel, while a buffer solution or blank control solution corresponding to the test solution is introduced into the reference channel. Preferably, the test solution uses the buffer solution in the reference channel as the base solvent system, with one or more additives. The test solution contains a target molecule; the buffer solution or blank control solution and the test solution are kept consistent or substantially consistent in terms of pH, ionic strength, osmotic pressure, temperature, viscosity and initial background refractive index, so that the reference channel can reflect the common-mode background changes caused by light source fluctuations, ambient temperature drift, mechanical vibration and fluid disturbance; the main difference between the test solution and the buffer solution or blank control solution is that the test solution contains a component that can interact with the target molecule, while the buffer solution or blank control solution does not contain the target interacting component, or contains a control component that does not interact specifically. Step two: Convert the refractive index change caused by molecular interactions into a phase difference change; When two or more biomolecules in the test solution combine, dissociate, or undergo conformational changes within the sensing channel, the overall refractive index or local effective refractive index of the solution undergoes a slight change. Since the probe light passes through the sensing channel and the reference light passes through the reference channel, the two beams of light acquire different optical path changes during propagation, thus forming a phase difference change related to molecular interactions when they are recombined. Step 3: Adjust the polarization phase adjustment component to bring the system into the weak measurement linear response region; Before formal testing, buffer solutions are introduced into the sensing channel and the reference channel respectively to bring the two channels to baseline. By using the SBC phase compensator to adjust the polarization state combination and relative phase relationship of the two different polarization components, the system output is made to be in the working range that is sensitive to small phase perturbations. Preferably, the post-selection polarizer is used to adjust the post-selection state to a state that is close to orthogonal but not completely orthogonal to the pre-selection state, so that the system can produce a weak amplification effect while maintaining sufficient output light intensity, which is convenient for stable acquisition by the area array camera. Step four: After weak measurement, select to convert the small phase difference into a change in light intensity; The two beams of light propagating through the sensing channel and the reference channel are re-combined by a post-beam combiner. The combined light then passes through an SBC phase compensator and a post-selected polarizer. The SBC phase compensator is used to adjust the relative phase relationship between the two different polarization components, and the post-selected polarizer is used to prepare a post-selected state that is nearly orthogonal to the pre-selected state. Since the post-selected state is nearly orthogonal to the pre-selected state, the small phase difference introduced by molecular interactions in the sensing channel will be amplified as a change in light intensity at the post-selected output. This converts the small refractive index changes and phase changes that are difficult to read directly into a two-dimensional light intensity change signal that can be recorded by the camera in real time. Step 5: Acquire two-dimensional light intensity images in real time and extract response curves; Two-dimensional light intensity images are continuously acquired using an area array camera and then selected for output. For each frame of the image, a sensing area and a reference area are selected respectively, and the average light intensity, total light intensity or other characterization values ​​of the corresponding areas are calculated to obtain the light intensity variation curves of the sensing channel and the reference channel over time. Step six: Extract light intensity signals and subtract background; A fixed region of interest is selected from the continuously acquired two-dimensional light intensity images. The average light intensity of the region in each frame is calculated to obtain the response curve of the output light intensity changing with time. The initial light intensity under buffer or blank sample conditions is used as the baseline to perform baseline subtraction on the subsequent light intensity signal to obtain the amount of light intensity change caused by molecular interaction. The background subtraction may include camera dark noise subtraction, initial baseline subtraction, and light source slow drift correction. Step 7: Establish calibration relationships and perform interaction analysis; Before detecting an unknown sample, a standard solution with a known refractive index or concentration is sequentially introduced into the sensing channel, and the light intensity changes in the sensing channel and the reference channel are collected simultaneously. After differential processing, a calibration curve is established with the refractive index change or sample concentration as the abscissa and the net light intensity change as the ordinate. During actual detection, the refractive index change, concentration change, or interaction response intensity of the sample to be tested is deduced from the net light intensity change generated by the sample, combined with the calibration curve. Alternatively, the dynamic process of molecular binding and dissociation can be analyzed based on the rise, stabilization, and fall of the net light intensity response over time.

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