Supercontinuum-based rapid two-dimensional correlation spectroscopy multi-component molecular concentration detection method and system

Abstract

The application discloses a kind of based on super surface fast two-dimensional correlation spectroscopy multi-component molecular concentration detection method.The incident polarized light of the application is incident from the substrate back of super surface to nano antenna unit, and then local surface plasmon is generated, for enhancing the infrared absorption intensity of gas molecule in the near field range of nano antenna unit;By collecting the signal of reflected spectrum, as polarized sensitive infrared spectrum data group.The corresponding prediction model is constructed by neural network, so as to realize the detection of multi-component molecular concentration.The application combines the unique design of super surface intrinsic polarization response physical mechanism with multi-dimensional spectral information, improves the detection sensitivity of multi-component substance from micro-nano device and spectrum.The polarized sensitive surface enhanced two-dimensional correlation spectroscopy in the application can be quickly obtained, and the detection speed is fast.

Description

Technical Field

[0001] This invention belongs to the field of micro-nano sensing and spectral detection technology, and specifically relates to a rapid two-dimensional correlation spectroscopy method and system for detecting the concentration of multi-component molecules based on metasurfaces. Background Technology

[0002] Surface-enhanced infrared (SIR) spectroscopy utilizes micro / nanostructures or metasurface materials to generate surface plasmons, creating a localized electromagnetic field enhancement in the near-field region. This field strongly couples with the analyte molecules, enhancing the infrared absorption intensity of molecules at the subwavelength scale and significantly improving the detection limit. Common methods for improving the sensitivity of SIR spectroscopy primarily focus on metasurface devices. One approach is to optimize the metasurface design to increase the amplification factor, i.e., to increase the local field enhancement factor, typically achieved by compressing the gaps between micro / nano antennas. This method reduces the effective sensing area and increases fabrication costs. Another approach is to increase the enrichment of the metasurface with molecules, i.e., directly accumulating more analyte molecules in the sensing region through specific chemical bonds, chemical reactions, physical adsorption, optical trapping, or defect structures. This method requires additional chemical stimulation, surface functionalization, or control of temperature, pressure, and optical power for specific molecules, increasing operational procedures and experimental complexity. This invention combines surface enhancement with spectroscopy, considering both metasurface devices and spectral aspects to improve detection sensitivity.

[0003] Two-dimensional correlation spectroscopy, by introducing external perturbation variables, obtains richer and more detailed characteristic variation patterns or related information compared to traditional one-dimensional spectroscopy, and is more sensitive to the detection of weak peaks and weak signals. Therefore, it has a more sensitive and stable detection effect for compounds or mixtures that are difficult to identify. However, commonly used perturbation variables such as temperature or pH are inflexible in operation, have long reaction times, and may damage the analyte or affect its performance, making them difficult to combine with surface-enhanced spectroscopy. The polarization perturbation variable proposed in this invention is easy to combine with surface-enhanced technology and is suitable for rapid two-dimensional correlation spectroscopy detection. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes a rapid two-dimensional correlation spectroscopy method and system for detecting the concentration of multiple components molecules based on metasurfaces.

[0005] A first aspect of the present invention provides a polarization-sensitive and broadband resonance-enhanced metasurface, comprising a substrate and nanoantenna units, wherein there are multiple nanoantenna units arranged in a matrix and disposed on the substrate;

[0006] The nanoantenna unit has an asymmetric structure, which causes the incident light to have different spectral responses when polarized in the x and y directions.

[0007] A second aspect of the present invention provides a rapid two-dimensional correlation spectroscopy multi-component molecular concentration detection device, comprising a micro gas chamber, wherein the micro gas chamber integrates the metasurface; the micro gas chamber also has a gas inlet and a gas outlet;

[0008] Incident polarized light is incident on the nanoantenna unit from the back side of the substrate, thereby generating localized surface plasmons to enhance the infrared absorption intensity of gas molecules in the near field of the nanoantenna unit; the signal of the reflection spectrum is collected as a polarization-sensitive infrared spectral data set.

[0009] A third aspect of the present invention provides a rapid two-dimensional correlation spectroscopy method for detecting the concentration of multiple components based on metasurfaces, using the aforementioned apparatus:

[0010] Spectral data of metasurface-enhanced multi-component mixtures were detected to obtain infrared spectral data set X;

[0011] The two-dimensional correlation spectral matrix X transformed from the infrared spectral data set X. Ф The known concentration data set Y of each component is substituted into a multi-component spectral quantitative analysis algorithm for modeling;

[0012] Based on the established model, for new multi-component substances with unknown concentrations, surface-enhanced spectral data are obtained and input into the model to realize the detection of the concentration of each component of the multi-component substance.

[0013] A fourth aspect of the present invention provides a rapid two-dimensional correlation spectroscopy multi-component molecular concentration detection system based on metasurfaces, comprising:

[0014] The model data construction unit is used to detect the spectral data of metasurface-enhanced multi-component mixed materials and obtain infrared spectral data set X.

[0015] Model building unit: used to transform the two-dimensional correlation spectral matrix X from the infrared spectral data set X. Ф The known concentration data of each component, Y, are used in a multi-component spectral quantitative analysis algorithm for modeling.

[0016] The model prediction unit is used to acquire surface-enhanced spectral data of new multi-component substances with unknown concentrations based on the established model, and input the data into the model to realize the concentration detection of each component of the multi-component substance.

[0017] The beneficial effects of this invention are:

[0018] 1. This invention proposes a new sensitivity enhancement scheme that combines the uniquely designed metasurface intrinsic polarization response physical mechanism with multi-dimensional spectral information to simultaneously improve the detection sensitivity of multi-component substances from both micro / nano device and spectral perspectives.

[0019] 2. It eliminates the need for high enhancement factors in micro / nano structures with ultra-narrow linewidths, as required in traditional surface-enhanced infrared absorption methods, thus reducing fabrication difficulty.

[0020] 3. It eliminates the need for procedures that increase molecular enrichment, thus simplifying experimental steps.

[0021] 4. Polarization-sensitive surface-enhanced two-dimensional correlation spectroscopy can be rapidly acquired, resulting in fast detection speed. Attached Figure Description

[0022] Figure 1 A schematic diagram of a broadband resonant-enhanced and polarization-sensitive metasurface;

[0023] Figure 2 This is a schematic diagram of the broadband resonance enhancement spectrum of a metasurface under different polarizations.

[0024] Figure 3 The flowchart shows a rapid two-dimensional correlation spectroscopy method for detecting multi-component substances based on metasurfaces.

[0025] Figure 4 A schematic diagram of an example structure of a broadband resonance-enhanced and polarization-sensitive metasurface;

[0026] Figure 5 for Figure 4 The example corresponds to the simulation results of broadband resonant spectra in the mid-infrared band;

[0027] Figure 6 This is a schematic diagram of an infrared detection experimental scheme;

[0028] Figure 7 This is a schematic diagram of a concentration detection system. Detailed Implementation

[0029] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Furthermore, in the description of the drawings, the same or equivalent parts are represented by the same symbols, and repeated descriptions are omitted. Also, the scale of the drawings may not necessarily match the actual scale.

[0030] The main technical concept of this invention:

[0031] The objective of this invention is achieved through the following technical solution:

[0032] The multi-component substances to be measured, such as biomolecules or gas molecules, have different characteristic absorption peaks in the infrared band. A metasurface is designed to target these absorption peaks, resulting in near-field optical enhancement in all characteristic absorption bands; that is, the metasurface exhibits broadband resonance enhancement. Simultaneously, the metasurface is polarization-sensitive, meaning that for specific absorption bands, different polarized light incident light produces different absorption intensities.

[0033] Spectral data of metasurface-enhanced multicomponent mixtures were detected, including infrared spectral data of multicomponent mixtures with different concentration ratios under various polarization states (taking two as examples). x ,X y [, and record the concentration data of each component Y, and transform the two-dimensional correlation spectral matrix X from X.] Ф Y is used in a multi-component spectral quantitative analysis algorithm for modeling.

[0034] Finally, based on the multi-component spectral quantitative analysis model, the surface-enhanced spectrum of a new multi-component substance with unknown concentration is quickly obtained and input into the model to achieve highly sensitive detection of the concentration of each component of the multi-component substance.

[0035] Figure 1 This is a schematic diagram of a metasurface device, consisting of a substrate 1 and a nanoantenna unit 2. The nanoantenna has an asymmetric structure, which causes the spectral response of the incident light to be different when the polarization is in the x-direction and the y-direction.

[0036] Figure 2 This is a schematic diagram of the broadband resonance-enhanced spectral response of the metasurface in the mid-infrared band, where λ1, λ2, ..., λ n These represent the characteristic absorption wavelengths of the n mixtures to be detected. The metasurface exhibits broadband resonance enhancement, meaning it enhances resonance for different characteristic wavelengths of various analytes. Simultaneously, the metasurface is polarization-sensitive, meaning its spectral responses in the x and y directions differ, and for a single characteristic absorption wavelength, the resonance intensities corresponding to the two polarization states are typically different.

[0037] Figure 3 This is a flowchart of a rapid two-dimensional correlation spectroscopy method for detecting multi-component substances based on metasurfaces. First, a polarization-sensitive and broadband resonance-enhanced metasurface is designed and fabricated to target multiple characteristic absorption peaks of the mixed molecules to be analyzed. Then, multiple sets (m sets) of metasurfaces with known concentrations Y(Y1, Y2…Y…) are analyzed. m Mixed molecules were adsorbed or prepared on the surface of metasurface devices; then, the x- and y-polarized infrared spectra of each group of mixed molecules were experimentally measured using an external infrared spectroscopy device, resulting in the spectral matrix X[X] of multiple samples. x ,X y (where the spectral data corresponding to the mixed molecules with concentration Y1 is X1[X) 1x ,X 1y Then, the two-dimensional correlation spectral matrix X of data X is constructed using methods such as feature extraction and two-dimensional correlation calculation. Ф Then, abnormal samples are removed, and the artificial neural network model is constructed by combining the known sample concentration data Y.

[0038] When a mixture of molecules of unknown concentration is combined with the aforementioned metasurface device, infrared spectral data (X-rays) of its different polarization states are detected. ’ [X x ’ ,X y ’ Then, using the same method described above, the two-dimensional correlation spectral matrix X of this set of data is obtained. Ф ’ Substituting this into the artificial neural network model constructed above, the unknown concentration Y of the mixed molecules to be tested can be derived. ’ .

[0039] Figure 4 For a specific metasurface design case, spectral detection of a mixed gas CO2 (λ1 = 4.3 μm), CH2O (λ2 = 5.7 μm), NO2 (λ3 = 6.3 μm), and SO2 (λ4 = 7.35 μm) with absorption peaks in the 4-8 μm range is achieved using a periodically folded gold nanowire array 3. The folding inflection points increase the order of the resonant modes, enabling multi-band surface plasmon resonance, i.e., increasing the bandwidth. Furthermore, the different shapes in the x and y directions provide polarization sensitivity. The substrate 1 is a calcium fluoride glass with high transparency in the infrared band. In the top view of a single nanoantenna unit 2, its period is P = 2.6 μm, the antenna lengths in the x and y directions are Lx = 2 μm and Ly = 1.7 μm, the asymmetry factor width is d = 300 nm, the nanoantenna width is w = 220 nm, and the thickness is 65 nm.

[0040] Figure 5 The broadband resonance spectrum of the aforementioned metasurface in the infrared band shows that resonance enhancement occurs at the characteristic peaks of the aforementioned gas under both x-polarized and y-polarized incident conditions.

[0041] Figure 6 The above-mentioned infrared detection experimental scheme is illustrated in the diagram. The above-mentioned metasurface (integrated into the micro gas chamber 5) has the gas concentration controlled by the gas inlet 3 and the gas outlet 4. The incident polarized light 6 is incident on the nanoantenna from the back of the substrate to generate local surface plasmons, which enhances the infrared absorption intensity of gas molecules in the near field range of the nanoantenna. The signal of the reflection spectrum 7 is collected as the above-mentioned polarization-sensitive infrared spectral dataset.

[0042] like Figure 7 As shown in the figure, an embodiment of the present invention illustrates a rapid two-dimensional correlation spectroscopy multi-component molecular concentration detection system based on metasurfaces; the system includes:

[0043] The model data construction unit is used to detect the spectral data of metasurface-enhanced multi-component mixed materials and obtain infrared spectral data set X;

[0044] Model building unit: used to transform the two-dimensional correlation spectral matrix X from the infrared spectral data set X. Ф The known concentration data set Y of each component is substituted into a multi-component spectral quantitative analysis algorithm for modeling;

[0045] The model prediction unit is used to acquire surface-enhanced spectral data of new multi-component substances with unknown concentrations based on the established model, and input the data into the model to realize the concentration detection of each component of the multi-component substance.

[0046] Embodiments of the rapid two-dimensional correlation spectroscopy multi-component molecular concentration detection system of the present invention can be applied to network devices. The device embodiments can be implemented through software, hardware, or a combination of both. Taking software implementation as an example, as a logical device, it is formed by the processor of the device loading the corresponding computer program instructions from the non-volatile memory into memory and executing them. The computer program is used to execute the rapid two-dimensional correlation spectroscopy multi-component molecular concentration detection method.

[0047] Although the present invention has been described with reference to certain aspects and embodiments, those skilled in the art will understand that changes in form and detail can be made, such as applying it to near-infrared, Raman, fluorescence enhancement and other fields without being limited to the infrared enhancement range, and using factors other than polarization as perturbation variables to achieve enhanced rapid two-dimensional spectral detection, without departing from the spirit and scope of the present invention.

Claims

1. A polarization-sensitive and broadband resonance-enhanced metasurface, comprising a substrate and a nanoantenna element, characterized in that: The nano-antenna units are multiple, arranged in a matrix, and disposed on the substrate; The nano-antenna unit has an asymmetric structure, which makes the spectral response of the incident light different when the polarization is in the x and y directions, and is used for rapid two-dimensional correlation spectral detection. The nano-antenna unit is a folded gold nanowire with an antenna length of 2 μm in the x-direction, an antenna length of 1.7 μm in the y-direction, an asymmetry factor width of 300 nm, an antenna width of 220 nm, and a thickness of 65 nm.

2. A rapid two-dimensional correlation spectroscopy multi-component molecular concentration detection device, comprising a micro gas chamber, characterized in that: The micro gas chamber integrates the metasurface described in claim 1; the micro gas chamber also has a gas inlet and a gas outlet; Incident polarized light is incident on the nanoantenna unit from the back side of the substrate, thereby generating localized surface plasmons to enhance the infrared absorption intensity of gas molecules in the near field of the nanoantenna unit; the signal of the reflection spectrum is collected as a polarization-sensitive infrared spectral data set.

3. The apparatus according to claim 2, characterized in that: The concentration of gas in the micro-gas chamber is controlled by the gas inlet and the gas outlet.

4. A rapid two-dimensional correlation spectroscopy method for detecting multi-component molecular concentrations based on metasurfaces, using the apparatus described in claim 2 or 3, characterized in that... The spectral data of metasurface-enhanced multi-component mixtures were detected, and infrared spectral data of multi-component mixtures with different concentration ratios under various polarization states were obtained (X). The two-dimensional correlation spectral matrix X transformed from the infrared spectral data set X. Ф The known concentration data set Y of each component is substituted into a multi-component spectral quantitative analysis algorithm for modeling; Based on the established model, for new multi-component substances with unknown concentrations, surface-enhanced spectral data are obtained and input into the model to realize the detection of the concentration of each component of the multi-component substance.

5. A rapid two-dimensional correlation spectroscopy multi-component molecular concentration detection system based on metasurfaces, employing the device described in claim 2 or 3, characterized in that, include: The model data construction unit is used to detect the spectral data of metasurface-enhanced multi-component mixed materials and obtain infrared spectral data set X; Model building unit: used to transform the two-dimensional correlation spectral matrix X from the infrared spectral data set X. Ф The known concentration data set Y of each component is substituted into a multi-component spectral quantitative analysis algorithm for modeling; The model prediction unit is used to acquire surface-enhanced spectral data of new multi-component substances with unknown concentrations based on the established model, and input the data into the model to realize the concentration detection of each component of the multi-component substance.

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