A detection system for enhancing D-dimer immunochemiluminescence signals

Abstract

The present invention provides a detection system for enhancing D-dimer immunochemiluminescence signals, comprising a resonant metasurface, a reaction module, a photoelectric detection module, and a data processing module. The resonant metasurface comprises a plurality of periodically arranged metasurface units; the metasurface units comprise a plurality of nanopillars with elliptical cylindrical structures, arranged in a zigzag array; the nanopillars are made of a high-refractive-index material with a refractive index greater than 1.3; and the nanopillars have a subwavelength structure. This system, based on the BIC metasurface for enhancing D-dimer immunochemiluminescence signals, combines high sensitivity, high specificity, and portability, overcoming many limitations of existing D-dimer detection technologies and enabling rapid and accurate detection of D-dimer.

Description

Technical Field

[0001] The present invention relates to the field of micro-nano optical technology, and in particular to a light filtering detection system based on BIC supersurface enhanced D-dimer immunochemiluminescence signals. Background Art

[0002] D-dimer is a key marker of coagulation activation and subsequent fibrinolysis. Produced only upon degradation of cross-linked fibrin, it has garnered significant attention in the diagnosis and treatment of coagulation disorders. D-dimer concentration testing is valuable in the diagnosis of venous thromboembolism and plays a crucial role in thrombolytic risk assessment, serving as a crucial intermediate outcome for adjunctive diagnosis and treatment.

[0003] Chemiluminescence immunoassay (CLIA) is a commonly used method for D-dimer detection. Using CLIA to measure D-dimer concentration, a D-dimer monoclonal antibody labeled with a chemiluminescent substrate (such as luminol or acridinium ester) binds to D-dimer, generating a light signal. A light signal meter then measures the number of photons to determine the luminescence intensity, which is then used to quantitatively determine the D-dimer concentration. This method offers advantages such as high accuracy, sensitivity, a clean environment, rapid detection speed, high automation, and suitability for large-scale testing, making it a promising approach for D-dimer detection. However, this method is costly. Currently, most chemiluminescence analyzers are imported, resulting in high equipment costs and limited domestic maturity. Furthermore, to meet the needs of D-dimer detection, this method's sensitivity needs to be further improved. Therefore, a D-dimer detection system with high sensitivity and low background noise is urgently needed to achieve rapid and accurate D-dimer detection. Summary of the Invention

[0004] To overcome the shortcomings of existing D-dimer detection technologies, improve detection sensitivity, reduce background noise, and achieve rapid and accurate D-dimer detection, the present invention provides a detection system (or instrument) based on a BIC metasurface-enhanced D-dimer immunochemiluminescence signal. The system comprises a resonant metasurface, a reaction module, a photoelectric detection module, and a data processing module.

[0005] The resonant metasurface is used to enhance the D-dimer immunochemiluminescence signal. The resonant metasurface comprises a plurality of periodically arranged metasurface units; each metasurface unit has the same structure; the metasurface unit comprises a plurality of nanopillars; the nanopillars are elliptical cylindrical structures; the nanopillars are arranged in a zigzag array; the size of the nanopillars is used to adjust the filter wavelength; the material of the nanopillars is a high refractive index material with a refractive index greater than 1.3; the nanopillars are subwavelength structures;

[0006] The reaction module is used to generate an immunochemiluminescent signal from D-dimer through an immunochemiluminescent reaction. The immunochemiluminescent reaction is performed on the resonant metasurface. The immunochemiluminescent reaction uses a D-dimer monoclonal antibody as one of the reactants, and the antibody is immobilized on the resonant metasurface using self-assembled monolayer technology.

[0007] A photoelectric detection module is used to detect the immunochemiluminescent signal, convert it into an electrical signal, enhance it, and then send it to a data processing module;

[0008] The data processing module is used to calculate the D-dimer concentration based on the data provided by the photoelectric detection module.

[0009] In some embodiments, the nanorods are made of silicon, titanium dioxide, or silicon nitride.

[0010] In some embodiments, the metasurface unit comprises 2 nanopillars.

[0011] In some embodiments, the immunochemiluminescent reaction is carried out using a direct chemiluminescence method, specifically including: combining a D-dimer antibody with a luminescent substrate to form a labeled antibody; using self-assembled monolayer technology to fix the labeled antibody on a resonant metasurface; adding a sample to be tested to the resonant metasurface, and the D-dimer in the sample to be tested contacts the labeled antibody and undergoes an immune reaction to form an immune complex; after the reaction is completed, washing to remove unbound free labeled antibodies, adding hydrogen peroxide or sodium hydroxide to make the environment alkaline, and stimulating the luminescent substrate in the immune complex to emit light.

[0012] In some more specific embodiments, the luminescent substrate is acridinium ester, rhodamine amide, luminol, or acridinium yellow.

[0013] In some embodiments, the photoelectric detection module specifically includes: a photomultiplier tube; a bandpass filter for filtering out stray light; and a reflector for adjusting and optimizing the direction of the light path.

[0014] In some more specific embodiments, the photomultiplier tube is a dynode type or an MCP type, and the number is 1; the central wavelength of the bandpass filter is 450 nm and the bandwidth is 40 nm; the number of the reflectors is 2.

[0015] In some embodiments, the data processing module calculates the D-dimer concentration using a D-dimer correction model, wherein the D-dimer correction model is established by a back-propagation BP neural network and regulating four hyperparameters in the BP neural network through a genetic algorithm.

[0016] The high-Q resonance of the BIC supersurface-enhanced D-dimer immunochemiluminescent signal detection system provided by the present invention is spectrally clean and has no additional resonance background, which allows for highly spectrally selective enhancement of spectrally rich D-dimer immunochemiluminescent signals. Therefore, the system can greatly improve the sensitivity of D-dimer detection, reduce background noise, and achieve rapid and accurate D-dimer detection. The supersurface unit size of the system is subwavelength, with smaller volume and lighter weight, and has the advantage of high integration when applied to D-dimer detection. The system has both high sensitivity, high specificity and portability, can overcome many limitations of existing D-dimer detection technologies, and achieve rapid and accurate detection of D-dimer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 Schematic diagram of the structure of the detection system for enhancing D-dimer immunochemiluminescence signal provided by the present invention;

[0019] Figure 2 Schematic diagram of the three-dimensional structure of the metasurface unit;

[0020] Figure 3 is a top view of the metasurface unit;

[0021] Figure 4 This is the optical path diagram of the photoelectric detection module;

[0022] Figure 5 Schematic diagram of the BIC position of the resonant metasurface in an embodiment of the present invention.

[0023] Explanation of symbols:

[0024] Metasurface unit-1, nanopillar-2. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

[0026] When light waves interact with certain dielectric subwavelength structures that meet certain size conditions, electric or magnetic resonance phenomena will occur (electromagnetic resonance may also exist simultaneously). Common types of resonance include Mie resonance, Fano resonance, bound state in the continuum (BIC), etc.

[0027] The BIC optical biosensor is a highly sensitive optical sensing technology based on the BIC principle. Its detection principle is that when target molecules (such as proteins, DNA, viruses, etc.) bind to the sensor surface, they cause a change in the local refractive index. This change triggers the BIC phenomenon. When the BIC resonance spectrum overlaps with the absorption fingerprint, the enhanced molecule-resonance cavity coupling leads to a significant change in the resonant frequency or intensity, allowing the molecular fingerprint to be extracted. This overlap can be achieved by changing the structural parameters and displacement parameters of the metasurface, thereby significantly enhancing the specific optical signal. By monitoring the changes in these optical signals, the concentration of the target molecule can be quantitatively detected.

[0028] BIC optical biosensors are typically composed of nanostructures, such as photonic crystals, metasurfaces, or waveguides, designed into specific geometries. They generate highly localized light fields across the continuous spectrum, enabling ultra-sensitive detection of minute changes. The highly sensitive optical sensing performance of BIC optical biosensors supports immunochemiluminescent detection of trace amounts of reaction substrates, demonstrating great potential in diverse applications such as bioscience, clinical medicine, and environmental monitoring, opening new possibilities for breaking bottlenecks in bioassays and other industries.

[0029] In BIC optical biosensors, optical metasurfaces, as a new morphological material with two-dimensional artificial periodic structures, possess subwavelength-level characteristic dimensions. Through design, they can control information such as the phase, amplitude, and polarization of light waves. Compared to traditional optical devices, metasurfaces have smaller sizes, higher resolutions, and ultra-thin thicknesses. They are also compatible with microelectronics manufacturing technologies and are easier to integrate into miniaturized optoelectronic devices. By breaking the symmetric structure of the metasurface unit, a symmetrically protected quasi-BIC with a high-quality (Q-value) resonance can be generated. When the resonance peak overlaps with the sensitive band of the D-dimer immunochemiluminescence signal, the D-dimer chemiluminescence signal can be significantly enhanced, thereby improving the speed and accuracy of D-dimer detection.

[0030] Based on the above concept, the present invention designs a detection system based on BIC metasurface-enhanced D-dimer immunochemiluminescence signal, which can overcome the shortcomings of existing detection technologies, greatly improve detection sensitivity, reduce background noise, and achieve rapid and accurate real-time monitoring.

[0031] The D-dimer detection system provided by the present invention is a reflective filtering system. The incident light is strongly reflected corresponding to the resonance peak of the metasurface, and there is high transmission on both sides of the resonance peak. By adjusting the structural parameters, the resonance peak position is perfectly aligned with the sensitive wavelength of D-dimer in the detection range, thereby being used to enhance the D-dimer immunochemiluminescence signal.

[0032] The D-dimer detection system provided by the present invention can fully utilize the resonance characteristics of dielectric micro-nanostructure units and can be used to enhance D-dimer immunochemiluminescence signals. Given that the resonance characteristics of the resonant metasurface are affected by structural parameters and asymmetry, the parameters are adjusted to perfectly align the position of the metasurface's resonance peak with the D-dimer-sensitive band. Compared to existing D-dimer detection solutions, the present invention is smaller, has a shorter detection time, is easier to integrate, and can achieve accurate detection of enhanced D-dimer luminescence signals.

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the following is a detailed description of the composition and functions of the detection system of the BIC supersurface-enhanced D-dimer immunochemiluminescence signal provided by the present invention in conjunction with the accompanying drawings.

[0034] It should be understood that the system is only used to detect D-dimer concentration, and D-dimer concentration is only intermediate result information that can be used for auxiliary diagnosis; and the detection system provided by the present invention can be integrated into a set of instruments for detecting D-dimer concentration.

[0035] like Figure 1 As shown, the D-dimer immunochemiluminescence signal detection system (or detection instrument) provided by the present invention includes a resonant metasurface, a reaction module, a photoelectric detection module and a data processing module.

[0036] First, the resonant metasurface is introduced. The resonant metasurface comprises a plurality of periodically arranged metasurface units 1, each of which has the same structure. The structure of the metasurface unit 1 is as follows: Figure 2 and Figure 3 As shown, each metasurface unit 1 comprises two nanopillars 2, each of which is an elliptical columnar structure. The nanopillars 2 are arranged in a zigzag array, and their size is used to adjust the filtering wavelength. The nanopillars 2 are made of a high-refractive-index, low-loss dielectric material within the operating wavelength band (such as silicon, titanium dioxide, or silicon nitride), making them easy to process and capable of generating resonant modes within nanostructures with sufficiently low aspect ratios.

[0037] The resonant metasurface is used to enhance D-dimer immunochemiluminescence signals. Specifically, when the metasurface unit 1 in the resonant metasurface interacts with the incident light wave, the resonance peak corresponds to a lower transmittance, while the two sides of the resonance peak have higher transmittances, thereby amplifying the light signal of the target wavelength. By changing the size and center position of the covering metasurface unit structure, the resonant wavelength will shift, and the filtering wavelength can be modulated while maintaining the filtering performance.

[0038] The above introduces the structure and function of the resonant metasurface. Next, we will introduce the reaction module.

[0039] The reaction module is used to generate an immunochemiluminescent signal from D-dimer through an immunochemiluminescent reaction. The immunochemiluminescent reaction is carried out on the metasurface and specifically includes: firmly attaching a D-dimer antibody labeled with an acridinium ester to the resonant metasurface through self-assembled monolayer technology combined with chemical cross-linking; when a sample containing D-dimer enters the reaction system, it comes into contact with the antibody immobilized on the metasurface and undergoes specific binding to form an immune complex; after the reaction is completed, unbound antibodies are washed away, and then hydrogen peroxide or sodium hydroxide is added to make the environment alkaline, causing the acridinium ester to decompose and emit light.

[0040] Self-assembled monolayers (SAMs) are ordered molecular assemblies that spontaneously form on a substrate surface. In immunochemiluminescent reaction modules, metal substrates are typically used. The basic principle is to utilize intermolecular interactions (such as van der Waals forces, hydrogen bonds, and covalent bonds) to orderly align organic molecules on the substrate surface, forming a monolayer. This monolayer is highly ordered and stable.

[0041] The reaction module has been introduced above. Next, we will introduce the photoelectric detection module. The photoelectric detection module is used to receive the immunochemiluminescence signal generated by the reaction module, convert it into an electrical signal, amplify it, and then send it to the data processing module.

[0042] The structure of the photoelectric detection module is as follows Figure 4 As shown, it includes a focusing lens, a bandpass filter, a reflector and a photomultiplier tube; the focusing lens is a parabolic mirror or an aspheric lens; the central wavelength of the bandpass filter is 450 nm and the bandwidth is 40 nm; the reflector is used to adjust and optimize the direction of the light path; the number of the reflectors is 2; the photocathode of the photomultiplier tube is perpendicular to the converged light path and the center is aligned; the output signal of the photomultiplier tube is an electrical signal.

[0043] The photoelectric detection module has been introduced above. Next, the data processing module will be introduced. The data processing module is used to calculate the D-dimer concentration based on the data provided by the photoelectric detection module.

[0044] The data processing module includes a filter and a signal processing algorithm. The filter is used to filter out noise; the signal processing algorithm uses a D-dimer calibration model to convert the electrical signal into D-dimer concentration data. The D-dimer calibration model is established by regulating the four hyperparameters of the back-propagation BP neural network using a genetic algorithm (GA).

[0045] The above describes the structure and functions of the detection system for enhancing D-dimer immunochemiluminescence signals based on the BIC metasurface provided by the present invention. The following provides a specific embodiment of the system for enhancing D-dimer immunochemiluminescence signals.

[0046] Figure 2 and Figure 3 The schematic diagram of the structure of the metasurface unit is shown in Figure 1. As mentioned above, the metasurface unit 1 includes two nanopillars 2 with the same structural size. The nanopillars 2 are elliptical cylinder structures and are arranged in a zigzag array. The height of the metasurface is H, and the period length of the metasurface in the x direction is p. x , the period length in the y direction is p y The length of the short axis of the cross section of the nanorod 2 is denoted as a, the length of the long axis is denoted as b, and the tilt angle between the long axis of the elliptical cylinder and the y-axis is denoted as θ.

[0047] The system operates in the near-ultraviolet band. The operating wavelength of the D-dimer immunochemiluminescence detection method is 430-470 nm. 462 nm is selected as the operating wavelength, and the incident light is linearly polarized light along the x direction.

[0048] The two nanopillars 2 in the metasurface unit 1 are deflected toward the center, with the tilt angle between the major axis of the elliptical cylinder and the y-axis being θ, and the asymmetry parameter ω = sinθ is defined. The purpose of introducing the asymmetry parameter is to break the symmetry of the metasurface unit structure, allowing the incident light wave to excite the symmetry-protected continuum bound states, or BICs, within it. The magnitude of the asymmetry parameter ω determines the quality factor, or Q value, of the electromagnetic BICs resonance generated when the light wave interacts with the metasurface. The asymmetry parameter ω and Q satisfy the following relationship:

[0049] Q∝ ω -2

[0050] From this relationship, it can be seen that the smaller the value of θ, the larger the resonance Q value. In order to make the resonance peak of the metasurface overlap with the sensitive wavelength of the immunochemiluminescence detection of D-dimer, θ=20° is used in this embodiment.

[0051] The material of nanopillar 2 is single crystal silicon, with a refractive index of 3.48 at the working wavelength. When the size parameters of the metasurface unit are scanned and optimized using electromagnetic simulation software, the position of the resonance peak is moved to the wavelength sensitive to D-dimer chemiluminescence by adjusting the structural parameters and displacement parameters. During the simulation process, it was observed that the parameter p x 、p y The changes of , a, b, H and θ will lead to the shift of BICs resonance wavelength. By optimizing the size of nanopillars to achieve resonance wavelength matching, the parameters are finally adjusted so that the resonance peak position is 430-470 nm. The size parameters of the resonant metasurface based on BICs are H = 120nm, p = 120nm, and p = 120nm. x =p y =297nm, a=90nm, b=270nm, θ=20°.

[0052] Finally, the effect of this embodiment for enhancing the D-dimer immunochemiluminescence signal intensity was obtained through electromagnetic simulation as follows: Figure 5 shown. Figure 5 The figure below shows a schematic diagram of the wavelength-dependent transmission coefficient of the D-dimer immunochemiluminescence signal enhanced by this system. The results demonstrate that this embodiment can be used to enhance the D-dimer immunochemiluminescence signal for detecting D-dimer concentration, with a resonance peak at 462 nm and transmission coefficients below 0.01.

[0053] It can be seen that compared with the prior art, the present invention has the following beneficial effects:

[0054] (1) The high-Q resonance of the BIC metasurface-enhanced D-dimer immunochemiluminescence signal detection system provided by the present invention is spectrally clean, without additional resonance background, allowing for highly spectrally selective enhancement of spectrally rich D-dimer immunochemiluminescence signals. Therefore, the system can greatly improve D-dimer detection sensitivity, reduce background noise, and achieve rapid and accurate D-dimer detection.

[0055] (2) The data processing module of the present invention uses a BP neural network to introduce a genetic algorithm to establish a D-dimer correction model, establish a highly robust D-dimer chemiluminescence signal enhancement detection system, and simultaneously complete the construction of a 4-parameter BP neural network to achieve rapid and accurate measurement of D-dimer concentration.

[0056] (3) The size of the metasurface unit of the present invention is sub-wavelength, smaller in size and lighter in weight, and has the advantage of high integration when applied to D-dimer detection.

[0057] In the description of the embodiments of the present application, words such as "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of the present application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0058] In the description of the embodiments of this application, the term "and / or" is merely a description of an association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B can represent the following three situations: A exists alone, B exists alone, and A and B exist at the same time. In addition, unless otherwise specified, the term "plurality" means two or more.

[0059] 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 identifying the technical features being referred to. Thus, features specified as "first" or "second" may explicitly or implicitly include one or more of such features. The terms "include," "comprising," "having," and their variations all mean "including but not limited to," unless otherwise specifically emphasized.

[0060] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made on the basis of the technical solution of the present invention should be included in the scope of protection of the present invention.

Claims

1. A D-dimer detection system, characterized in that: include: Resonant metasurface for enhancing D-dimer immunochemiluminescence signals; The resonant metasurface comprises a plurality of periodically arranged metasurface units; the metasurface units comprise two nanopillars; the nanopillars are elliptical column structures; the nanopillars are arranged in a zigzag array, one end of the two nanopillars deflects toward the center position and approaches each other, and the long axis of the elliptical column is inclined at a certain angle to the vertical direction; the material of the nanopillars is a high refractive index material with a refractive index greater than 1.3; the nanopillars are subwavelength structures; A reaction module, configured to generate an immunochemiluminescent signal from D-dimer through an immunochemiluminescent reaction; the immunochemiluminescent reaction uses a D-dimer monoclonal antibody as one of the reactants, the antibody being immobilized on the resonant metasurface through self-assembled monolayer technology, and the immunochemiluminescent reaction being carried out on the resonant metasurface; the luminescent substrate of the immunochemiluminescent reaction being an acridinium ester, rhodamine amide, luminol, or acridinium yellow; A photoelectric detection module is used to detect the immunochemiluminescent signal, convert it into an electrical signal, enhance it, and then send it to a data processing module; The data processing module is used to calculate the D-dimer concentration based on the data provided by the photoelectric detection module.

2. The D-dimer detection system according to claim 1, characterized in that The material of the nanorods is silicon, titanium dioxide or silicon nitride.

3. The D-dimer detection system according to claim 1, characterized in that The photoelectric detection module specifically includes: a photomultiplier tube; a bandpass filter for filtering out stray light; and a reflector for adjusting and optimizing the direction of the light path.

4. The D-dimer detection system according to claim 3, characterized in that The photomultiplier tube is a dynode type or an MCP type.

5. The D-dimer detection system according to claim 3, wherein The central wavelength of the bandpass filter is 450 nm and the bandwidth is 40 nm.

6. The D-dimer detection system according to claim 1, characterized in that The data processing module calculates the D-dimer concentration using a D-dimer correction model, wherein the D-dimer correction model is established by a back-propagation BP neural network with hyperparameters regulated by a genetic algorithm.

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