A medium nanosphere array microcavity particle sensing system

Abstract

The application discloses a particle sensing system based on a limited-size medium nanosphere array, which comprises an excitation light regulation module, a pinhole filter, a prism module, a limited-size medium nanosphere array chip and a microscopic spectrum analysis module. The excitation light regulation module and the pinhole filter provide wide-spectrum parallel light illumination for the medium nanosphere array. The wide-spectrum parallel light is used for light excitation at a specific angle through the prism module and is irradiated on the limited-size medium nanosphere array, so that the excitation of array characteristic peaks is realized. The scattering spectrum of the limited-size nanosphere array is tested through the microscopic spectrum analysis module, and sensing is realized according to the movement of the characteristic peaks. The system is characterized in that the height direction of the particle sensing unit is reduced to the scale of hundreds of nanometers, which is far smaller than the size of a traditional optical resonance cavity such as a microsphere. In combination with the large-angle incidence of the prism and the vertical collection of the microscopic light path, the system stray light can be significantly reduced, and high-sensitivity sensing in the nanometer scale is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to a medium nanosphere array microcavity particle sensing system, belonging to the field of nano-optical sensing systems. BACKGROUND

[0002] With the development of science and technology, people have witnessed the update of mobile phones, computers and the like from generation to generation - the functions are increasingly rich, and the quality and size are gradually lightened and thinned. With the development of micro-nano optoelectronic device technology, mobile phones will integrate more micro-nano scale devices for realizing new functions such as health monitoring and food safety detection. Micro-nano scale optoelectronic devices will be the core components of future electronic equipment, and the terminals of these electronic devices can be divided into two parts: high-performance sensors and communication devices. Therefore, people have an increasingly great demand for sensing systems with higher degrees of freedom and greater sensitivity.

[0003] At present, there are some detection systems for PM2.5 (or PM1) particles on the market, which detect particles with sizes greater than 2.5 μm (greater than 1 μm), respectively, and the detection of smaller nano-particles is a future development trend. This is because the development of nanotechnology is increasing, and some nano-particles currently exhibit cytotoxicity, and there is evidence that inhaling nano-structures can damage people's lung function, so effective detection of these nano-level particles is needed.

[0004] In the past two decades, nano-photonics has developed rapidly. Generally speaking, due to the existence of diffraction and other phenomena, the traditional structure of the microscopic system cannot realize nanoscale microscopic sensing, which limits the research scope of nanosensing. Whispering gallery mode (WGM) mainly detects the shift of characteristic peaks to obtain information, and this testing method provides micron-level sensing information. However, the Gaussian light gathered in multiple directions will produce different characteristic peak shifts, and it is not easy to distinguish and judge, and it is not easy to be used as a general technology of sensing system. In addition, generally speaking, microspheres smaller than 2 microns cannot support the whispering gallery mode, and the characteristic peaks cannot be detected. Therefore, the WGM mode excitation still needs to be developed, and a sensing system with higher degrees of freedom and greater sensitivity is sought.

[0005] By arranging nanospheres into an array, in which light can be converted into transversely propagating guided modes, WGM modes can also be supported. In this WGM mode, the structure can be significantly reduced in the thickness direction compared to the above-mentioned 2-micron size, and a large quality factor can also be achieved. The structures reported in the literature are usually implemented with infinite periodic structures. However, macroscopic nanosphere arrays are difficult to process and do not conform to the miniaturization direction of integrated optical sensing. SUMMARY

[0006] Technical problems: The purpose of the present application is to provide a particle sensing system for limited size medium nanosphere array at nanometer level, solve the problem that light path is too scattered and high sensitivity sensing cannot be obtained, and the size of traditional microsphere optical resonance cavity is too large and is not convenient for integration and nanometer level sensing.

[0007] Technical scheme: The particle sensing system based on limited size medium nanosphere array comprises an excitation light regulation module, a pinhole filter, a prism module, a limited size medium nanosphere array, a transparent substrate and a microscopic spectrum analysis module; the excitation light sequentially passes through the excitation light regulation module, the pinhole filter and the prism module to provide wide spectrum parallel light illumination for the limited size medium nanosphere array; the wide spectrum parallel light is used to realize specific angle light excitation through the prism module and is irradiated on the limited size medium nanosphere array on the transparent substrate to realize excitation of array characteristic peaks; the scattering spectrum of the limited size medium nanosphere array is tested through the microscopic spectrum analysis module, and sensing is realized according to the movement of the characteristic peaks.

[0008] Among them.

[0009] The excitation light regulation module is composed of a halogen tungsten lamp / xenon lamp, a spatial filter and a prism expander arranged in sequence.

[0010] The pinhole diameter of the pinhole filter is 2 microns to 500 microns.

[0011] The prism module is a coupling prism with a refractive index of 1.9-2.3, and the wide spectrum parallel light is adjusted to 25.7°-90° through the prism.

[0012] The limited size medium nanosphere array is a dense arrangement of medium nanospheres with a diameter of 10-1000 nanometers in a honeycomb manner, the spacing between each medium nanosphere is 2-50 nanometers, the size of each medium nanosphere array unit is 10 nanometers-50 microns, and the number of medium nanospheres contained in each unit is 9-1000.

[0013] The material of the medium nanosphere includes silicon dioxide, aluminum oxide, silicon nitride or titanium oxide.

[0014] The transparent substrate includes a quartz substrate, a polydimethylsiloxane substrate, a polyethylene substrate, a polystyrene substrate, an indium tin oxide substrate or an aluminum-doped indium oxide substrate.

[0015] The microscopic spectrum analysis module is composed of a spectrum analyzer, a line array spectrum camera and a computer, and changes the light signal of the characteristic peak into an electric signal for sensing analysis.

[0016] The test method of the particle sensing system based on limited size medium nanosphere array is as follows:

[0017] First step: the regulation of excitation light: the excitation light is regulated to be wide-spectrum parallel light by an excitation light regulation module and a pinhole filter, and is focused on a prism module, so that the regulation of optical devices is achieved to obtain excitation light of a specific angle;

[0018] Second step: excitation of the characteristic peak of the nanosphere array: the excitation light of the specific angle is irradiated on the limited-size medium nanosphere array, and the position and shape characteristics of the characteristic peak are analyzed by a microscopic spectrum analysis module;

[0019] Third step: sensing of micro-nanoparticles: 200-400 nanometer nanospheres are added on a transparent substrate; part of the excitation light of the specific angle obtained above is irradiated on the transparent substrate, and the other part is scattered into the microscopic spectrum analysis module, the characteristic peak obtained for the second time is observed in the microscopic spectrum analysis module, and sensing analysis is performed according to the shift of the characteristic peak compared with before the addition of the nanometer microspheres.

[0020] Beneficial effects:

[0021] 1. A nanometer-scale WGM echo wall mode excitation method is proposed, an ordered arrangement of medium nanospheres is adopted, the height direction of the particle sensing unit is reduced to the order of hundreds of nanometers, the size is far smaller than that of the traditional microsphere optical resonant cavity, and the sensing unit can realize a large quality factor, which provides a beneficial method for nanometer particle sensing.

[0022] 2. A nanometer-scale micro-nano structure particle sensor is proposed, a single-direction high-efficiency prism excitation light excitation WGM characteristic peak scheme is adopted, the interference of stray light is suppressed, high-precision, rapid, non-destructive high-degree nanometer nanometer-scale sensing detection can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a schematic diagram of a particle sensing system based on a limited-size medium nanosphere array proposed by the application.

[0024] Figure 2 It is a test flowchart of a particle sensing system based on a limited-size medium nanosphere array.

[0025] Figure 3 It is a schematic diagram of a 200nm microsphere array sensing test principle.

[0026] Figure 4 It is a schematic diagram of a particle sensing system based on a 200nm-diameter silica medium nanosphere array (array side length 25mm square);

[0027] Figure 5Figure 1 is a schematic diagram of a particle sensing system based on a silica dielectric nanosphere array with a diameter of 100 nm (square array with a side length of 10 mm).

[0028] The figure shows: excitation light control module 1, halogen tungsten / xenon lamp 1.1, spatial filter 1.2, prism beam expander 1.3, pinhole filter 2, prism module 3, transparent substrate 5, limited size dielectric nanosphere array 4, microscopic spectral analysis module 6, spectral analyzer 6.1, linear array spectral camera 6.2, and computer 6.3, 200 nm test microspheres 7, organic solvent 8, mixed solution 9, water 10, silica microsphere layer 11, polydimethylsiloxane stamp 12. DETAILED DESCRIPTION

[0029] The present application proposes a particle sensing system of limited size dielectric nanosphere array, which uses wide spectrum parallel light illumination and obtains specific angle prism excitation light through prism to excite characteristic sharp peaks on the honeycomb-like closely packed microsphere array with a size of 200-1000 nm, tests the scattering spectrum of the limited size nanosphere array through the microscopic spectral analysis module, and realizes sensing according to the movement of the characteristic sharp peaks. The system features are to reduce the height direction of the particle sensing unit to the order of nanometers, which is much smaller than the traditional optical resonant cavity such as microsphere, and the sensing unit can realize large quality factor at the same time, combined with the large angle incidence of the prism and the vertical collection of the microscopic light path, which can significantly reduce the stray light of the system, realize high sensitivity sensing at the nanoscale, and provide an effective research method for the research of nanoscale particle sensing system.

[0030] The present application is a particle sensing system of limited size dielectric nanosphere array, which includes an excitation light control module, a pinhole filter, a prism module, a limited size dielectric nanosphere array, a transparent substrate, and a microscopic spectral analysis module. The excitation light control module and the pinhole filter provide wide spectrum parallel light illumination for the dielectric nanosphere array, the wide spectrum parallel light realizes specific angle light excitation through the prism module, and irradiates on the limited size dielectric nanosphere array to realize the excitation of array characteristic sharp peaks, the scattering spectrum of the limited size nanosphere array is tested through the microscopic spectral analysis module, and sensing is realized according to the movement of the characteristic sharp peaks.

[0031] The technical solutions of the present application are further described below in combination with the drawings. As shown in Figure 1As shown, this invention is a particle sensing system for a finite-size dielectric nanosphere array. The system includes an excitation light modulation module 1, a pinhole filter 2, a prism module 3, a finite-size dielectric nanosphere array 4, a transparent substrate 5, and a microscopic spectral analysis module 6. The excitation light modulation module 1 consists of a halogen tungsten / xenon lamp 1.1, a spatial filter 1.2, and a prism beam expander 1.3. The excitation light modulation module and the pinhole filter 2 together provide broadband parallel light illumination for the dielectric nanosphere array 4. The broadband parallel light is excited at a specific angle through the prism module 3 and illuminates the finite-size dielectric nanosphere array 4 on the transparent substrate 5, achieving the excitation of the array's characteristic peaks. The scattering spectrum of the finite-size nanosphere array is measured by a spectrometer 6.1, a linear array spectral camera 6.2, and a computer 6.3 in the microscopic spectral analysis module 6, and sensing is achieved based on the movement of the characteristic peaks.

[0032] The excitation light control module 1 consists of a halogen tungsten / xenon lamp 1.1, a spatial filter 1.2, and a prism beam expander 1.3. The pinhole filter 2 has a pinhole diameter of 2-500 micrometers; the prism module 3 is a coupling prism with a refractive index of 1.9-2.3, allowing broadband parallel light to be incident at an angle of 25.7°-90° after passing through the prism. The finite-size dielectric nanosphere array 4 consists of silica dielectric nanospheres with a diameter of 200-1000 nm arranged in an ordered manner in a square shape with a side length of 25-50 mm; the microscopic spectral analysis module 6 consists of a spectrometer 6.1, a linear array spectral camera 6.2, and a computer 6.3, which converts changes in characteristic peaks (optical signals) into electrical signals for sensing and analysis.

[0033] The following is combined Figure 2 Explain the instrument's workflow:

[0034] Step 1: Control of excitation light: The beam is controlled into a broadband parallel light by the excitation light control module 1 and the pinhole filter 2 and focused onto the prism 3, thereby achieving the control of the optical device to obtain excitation light at a specific angle.

[0035] Step 2: Excitation of characteristic peaks of the nanosphere array: The medium nanosphere array 4 is irradiated with excitation light at a specific angle, and the position and shape characteristics of its characteristic peaks are analyzed by the microspectral analysis module 6.

[0036] Step 3: Sensing of micro / nano particles: Nanospheres with a size of 200-400 nm are added to the transparent substrate 5. Part of the prism excitation light obtained above is irradiated onto the transparent substrate 5, and the other part is scattered into the microscopic spectral analysis module 6. The characteristic peaks obtained a second time are observed in the microscopic spectral analysis module; and compared with those before the addition of nanospheres, sensing analysis is performed based on the shift of the characteristic peaks.

[0037] Example 1:

[0038] Fabrication and transfer of 200nm nanoarray microspheres: such as Figure 3 As shown, the processing and transfer of microspheres were accomplished using a polydimethylsiloxane stamping method. The polydimethylsiloxane stamp depicted in the figure has a period of 100 micrometers and an effective area > 25 × 25 mm. 2 The diagram shows a polydimethylsiloxane stamp arranged in a square pattern, with a line width of <1μm and a height of 1μm. The silica in the diagram is a mixture of tetraethyl orthosilicate (top layer), ethanol, and other organic solvents in a specific ratio, with an aqueous solution as the bottom layer. After the organic solvents evaporate, a single-molecule silica microsphere film is obtained at the liquid surface boundary. This film can be replicated onto a transparent substrate 5 using the polydimethylsiloxane stamp without damaging its original structure, resulting in a 200nm nanoarray of microspheres.

[0039] like Figure 4 The excitation light control module shown consists of a halogen tungsten / xenon lamp, a spatial filter, and a prism beam expander. The pinhole filter has a pinhole diameter of 50 micrometers; the prism module is a coupling prism with a refractive index of 2, allowing broadband parallel light to be incident at 25.7°-90° after passing through the prism. The finite-size dielectric nanosphere array consists of ordered arrangement of 200 nm diameter silica dielectric nanospheres in a square with a side length of 25 mm; the microspectral analysis module consists of a spectrometer, a linear array spectrometer camera, and a computer, converting changes in characteristic peaks (optical signals) into electrical signals for sensing analysis. Taking polymer microspheres as an example, when polymer microspheres are added to the detection system, the shift of characteristic peaks can be observed in the spectrometer in WGM mode to realize sensing applications. The excitation light control module and pinhole filter provide broadband parallel light illumination for the dielectric nanosphere array. The broadband parallel light is excited at a specific angle through the prism module and irradiates the finite-sized dielectric nanosphere array to excite the array's characteristic peaks. The scattering spectrum of the finite-sized nanosphere array is tested by the microspectral analysis module, and sensing is achieved based on the movement of the characteristic peaks.

[0040] Example 2:

[0041] like Figure 5The system is shown as 25 100 nm silica medium microspheres in a square order arrangement. The excitation light modulation module is shown as consisting of a halogen tungsten lamp, a spatial filter, and a prism expander, which provides the system with wide-spectrum parallel light. The pinhole filter has a vacuum diameter of 25 microns; the prism is a coupling prism with a refractive index of 2.3, and the wide-spectrum parallel light is incident on the prism at an angle of 25.7°-90°. The limited-size medium nanosphere array is an effective arrangement of 100 nm silica medium nanospheres in a square pattern with a side length of 10 mm; the microspectral analysis module consists of a spectral analyzer, a linear array spectral camera, and a computer, which converts the changes in the characteristic peaks (optical signals) into electrical signals for sensing analysis. In the sensing system, 200 nm polymer microspheres to be detected are added, and in the WGM mode, a significant characteristic peak shift is observed in the microspectral analysis module to obtain sensing information.

Claims

1. A particle sensing system based on finite size dielectric nanosphere array, characterized in that, The sensing system comprises an excitation light regulation module (1), a pinhole filter (2), a prism module (3), a limited-size medium nanosphere array (4), a transparent substrate (5), and a microscopic spectrum analysis module (6); the excitation light sequentially passes through the excitation light regulation module (1), the pinhole filter (2), and the prism module (3) to provide wide-spectrum parallel light illumination for the limited-size medium nanosphere array (4); the wide-spectrum parallel light realizes light excitation at a specific angle through the prism module (3) and is irradiated on the limited-size medium nanosphere array (4) on the transparent substrate (5), so as to realize excitation of array feature peaks; the scattering spectrum of the limited-size medium nanosphere array (4) is tested through the microscopic spectrum analysis module (6); and obvious feature peak shift is observed in the microscopic spectrum analysis module under the whispering gallery mode to obtain sensing information. The excitation light regulation module (1) is composed of a halogen tungsten lamp / xenon lamp (1.1), a spatial filter (1.2), and a prism expander (1.3) arranged in sequence. The prism module (3) is a coupling prism with a refractive index of 1.9-2.3; the wide-spectrum parallel light is adjusted to an incident angle of 25.7°-90° through the prism. The limited-size medium nanosphere array (4) is a dense arrangement of medium nanospheres with a diameter of 10-1000 nanometers in a honeycomb manner; the interval between each medium nanosphere is 2-50 nanometers; the size of each medium nanosphere array unit is 10 nanometers-50 micrometers; and each unit contains 9-1000 medium nanospheres.

2. The particle sensing system based on a limited size medium nanosphere array of claim 1, wherein, The pinhole diameter of the pinhole filter (2) is 2 micrometers to 500 micrometers.

3. The particle sensing system based on a limited size medium nanosphere array of claim 1, wherein, The material of the medium nanosphere includes silicon dioxide, aluminum oxide, silicon nitride, or titanium oxide.

4. The particle sensing system based on a limited size medium nanosphere array of claim 1, wherein, The transparent substrate (5) includes a quartz substrate, a polydimethylsiloxane substrate, a polyethylene substrate, a polystyrene substrate, an indium tin oxide substrate, or an aluminum-doped indium oxide substrate.

5. The particle sensing system based on a limited size medium nanosphere array of claim 1, wherein, The microscopic spectrum analysis module (6) is composed of a spectrum analyzer (6.1), a linear array spectrum camera (6.2), and a computer (6.3); the change of the feature peak is converted into an electrical signal for sensing analysis.

6. A test method of a particle sensing system based on a limited size medium nanosphere array according to claim 1, characterized in that, The test method of the particle sensing system is as follows: First step: regulation of excitation light: the excitation light is regulated to wide-spectrum parallel light through the excitation light regulation module (1) and the pinhole filter (2) and is focused on the prism module (3), so as to realize regulation of optical devices to obtain excitation light at a specific angle; Second step: excitation of nanosphere array feature peaks: the excitation light at the specific angle is irradiated on the limited-size medium nanosphere array (4); and the position and shape characteristics of the feature peaks are analyzed through the microscopic spectrum analysis module (6); Third step: sensing of micro-nanoparticles: the nanospheres with a size of 200-400 nanometers are added on the transparent substrate (5); part of the excitation light at the specific angle obtained above is irradiated on the transparent substrate (5), and the other part is scattered into the microscopic spectrum analysis module (6); the feature peaks obtained for the second time are observed in the microscopic spectrum analysis module (6); and sensing analysis is performed according to the shift of the feature peaks in comparison with the feature peaks before the nanospheres are added.

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