Organic solvent Raman spectrum detection system of integrated micro-fluidic chip

Abstract

The invention provides an organic solvent Raman spectrum detection system integrated with a micro-fluidic chip, which relates to the technical field of spectrum, and comprises a Raman spectrum excitation detection light path, a micro-fluidic chip, a positioning table, a peristaltic pump, a power supply, an instrument shell and spectrum analysis software, an organic solvent enters the channel of the micro-fluidic chip from the sample inlet under the driving of the peristaltic pump, and under the control of the positioning table, laser emitted by the laser can be ensured to be accurately focused on the organic solvent in the micro-fluidic chip after passing through a light path; raman signals for exciting the organic solvent are collected by a detection light path and transmitted to spectral analysis software in an upper computer for processing, so that Raman spectrum detection of the organic solvent is realized; in addition, external Raman reflection signals can be introduced into a detection light path in the instrument through the optical fiber coupler, then detection of samples outside the instrument is completed, and the in-situ detection device has the advantages of being low in sample consumption and portable and can meet the requirement of in-situ detection.

Description

Technical Field

[0001] The invention relates to the technical field of spectral analysis, and in particular to an organic solvent Raman spectroscopy detection system integrated with a microfluidic chip. Background Art

[0002] In the past few decades, both microfluidics and Raman spectroscopy have made great progress. Raman spectroscopy is a spectral technology based on the principle of Raman scattering. It obtains the structure and composition information of the substance by measuring the frequency shift of the scattered light of the sample. Compared with traditional spectroscopy technology, Raman spectroscopy has the advantages of non-destructive, high sensitivity and rapidity. In the field of liquid component detection, Raman spectroscopy is widely used in food safety, drug analysis, and environmental monitoring. By analyzing the Raman spectrum of the sample, the composition and concentration of different compounds can be accurately identified, providing an important analytical means for research in the fields of chemistry and biology. Microfluidics is a method of experiment and analysis using microfluidic control technology. This technology has the advantages of low reagent consumption, fast reaction speed, and simple operation. It is usually used to realize miniaturized and efficient chemical analysis, biological analysis and experimental platform. Microfluidics combined with Raman spectroscopy can not only accurately control and analyze samples, but also has very high resolution and sensitivity to achieve high sensitivity and high selectivity detection of heavy metal ions in trace samples.

[0003] However, in the existing Raman spectroscopy detection equipment, it is not convenient to inject the sample to be detected during spectral detection, and there are problems such as complex assembly and maintenance of the spectral projection mechanism. Due to the special size and shape of the microfluidic chip, when the fluid in it is used as the sample to be detected, it is difficult for the current general Raman spectrometer to analyze it conveniently and effectively. In addition, large Raman spectrometers are often unable to perform on-site detection due to their large size and inconvenient mobility. Moreover, such instruments are highly professional and difficult to operate, which limits their application in more fields. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides an organic solvent Raman spectroscopy detection system integrated with a microfluidic chip.

[0005] The technical solution of the present invention is as follows:

[0006] An organic solvent Raman spectroscopy detection system integrated with a microfluidic chip, comprising a Raman spectroscopy excitation detection optical path, a microfluidic chip, a positioning stage, a peristaltic pump, a power supply, an instrument housing and spectral analysis software;

[0007] The microfluidic chip is formed by bonding polydimethylsiloxane and a glass slide after plasma treatment;

[0008] The spectral analysis software includes Raman spectral data preprocessing, feature extraction and classification recognition; the Raman spectral data preprocessing is specifically: applying the adaptive iterative reweighted penalized least squares method to subtract the spectral baseline from the obtained Raman spectrum, remove noise, and retain the effective information of the Raman spectrum; the feature extraction is specifically: using the peak search algorithm to screen out the characteristic peaks at specific wavenumber positions from the preprocessed spectral data; the classification recognition is specifically: matching the spectral data to the database through the search algorithm for identification, and then performing qualitative or quantitative analysis on unknown organic solvent samples; the database contains the spectral characteristics of known compounds and their physicochemical property information;

[0009] The instrument housing includes an aluminum alloy plate, a cover plate, a panel and a partition plate, and the panel, partition plate and cover plate are all made of acrylic material; the panels on all sides are fixed to the aluminum alloy plate at the bottom by screws, and the partition plate is vertically placed in the middle of the panel, with the same distance from the panels on both sides, and is fixed to the panel by a slide rail; a slide rail is provided at the upper end of the panel, and the cover plate is covered on the panel by the slide rail;

[0010] The partition is provided with a light-through hole; the enclosure is provided with a sample inlet, a sample outlet, and a fiber optic coupler opening;

[0011] The aluminum alloy plate is provided with lifting handles on both sides, and the lifting handles are fixed to the aluminum alloy plate by screws;

[0012] The Raman spectrum excitation detection optical path includes a laser, an objective lens, a converging lens, a beam splitter, a filter, an optical micropore, a first reflector, a second reflector, a grating, a CCD module and a fiber coupler; wherein the fiber coupler is fixed in the fiber coupler opening of the enclosure, and the bases of the laser, the objective lens, the converging lens, the beam splitter, the filter, the optical micropore, the first reflector, the second reflector, the grating and the CCD module are fixed to the aluminum alloy plate by screws; the fiber coupler, the beam splitter and the laser are sequentially placed on the same straight line, and the microfluidic chip and the objective lens, the beam splitter, the light hole on the partition, the filter, the converging lens, the optical micropore and the first reflector are sequentially placed on the same straight line, the first reflector, the second reflector and the grating are arranged at a 45° angle to the incident light, and the CCD module is arranged at a 90° angle to the incident light;

[0013] The laser power is 100mW, which is used to generate 532nm green laser; the CCD module is connected to the host computer through a USB interface fixed to the instrument housing through a data cable;

[0014] The peristaltic pump is connected to two hoses, one of which is connected to the microfluidic chip, and the other is passed through the sampling port and placed outside the instrument in a sampling tube containing an organic solvent; the adjustment button of the peristaltic pump is fixed to the instrument housing and is used to adjust the sample flux during detection;

[0015] The positioning stage is composed of a manually adjustable XY two-dimensional micro-displacement platform and a chip fixture, which are fixed by screws;

[0016] The power supply is used to power the peristaltic pump and the laser, and the main power switch of the power supply is fixed at the bottom of the instrument housing.

[0017] The beneficial effects of adopting the above technical solution are:

[0018] The present invention provides an organic solvent Raman spectroscopy detection system integrated with a microfluidic chip, which specifically includes the following beneficial effects:

[0019] (1) The present invention drives the external sample into the microfluidic chip through the sampling port through a peristaltic pump, which facilitates the real-time sampling of the object to be detected during spectral detection.

[0020] (2) The present invention adopts a bottom surface detection method for the microfluidic chip, and the pipeline for transporting the sample will not contact the detection optical path to affect the detection effect, and will not limit the design of the inlet and outlet of the channel in the microfluidic chip.

[0021] (3) The design of the pull-out cover of the present invention facilitates the replacement of different types of microfluidic chips, and facilitates assembly, use and equipment maintenance.

[0022] (4) The present invention designs a positioning platform that can fix the microfluidic chip, which is not only applicable to various microfluidic chips, but also helps to adjust the position of the microfluidic chip in the XY plane, making it convenient for the laser detection light source to accurately focus on the sample in the microfluidic chip.

[0023] (5) In addition, the portable design and power supply allow the instrument to be used for sampling and testing in field environments, such as monitoring various water quality samples such as tap water, surface water, and industrial wastewater, to achieve real-time monitoring and analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure of an instrument housing in an organic solvent Raman spectroscopy detection system integrated with a microfluidic chip according to the present invention;

[0025] In the figure, 1-aluminum alloy plate, 2-enclosure plate, 3-partition plate, 17-cover plate, 19-lifting handle, 20-inlet, 21-outlet, 22-light hole, 23-power switch, 24-adjustment button, 25-USB interface, 26-fiber coupler;

[0026] Figure 2 A top view of the interior of an organic solvent Raman spectroscopy detection system integrated with a microfluidic chip according to the present invention;

[0027] In the figure, 4-peristaltic pump, 5-positioning stage, 6-microfluidic chip, 7-laser, 8-beam splitter, 9-objective lens, 10-filter, 11-converging lens, 12-optical microaperture, 13-first reflector, 14-second reflector, 15-grating, 16-CCD module, 18-power supply;

[0028] Figure 3 The Raman detection spectra of different organic solvents;

[0029] Figure 4 The Raman detection spectra of the same organic solvent with different concentrations;

[0030] Figure 5 It is a linear curve diagram between the ethanol concentration detected by Raman spectroscopy and the actual concentration. DETAILED DESCRIPTION

[0031] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0032] An organic solvent Raman spectroscopy detection system integrated with a microfluidic chip, comprising a Raman spectroscopy excitation detection optical path, a microfluidic chip, a positioning stage, a peristaltic pump, a power supply, an instrument housing and spectral analysis software;

[0033] The microfluidic chip 6 is formed by bonding polydimethylsiloxane and a glass slide after plasma treatment;

[0034] The spectral analysis software includes Raman spectral data preprocessing, feature extraction and classification recognition; the Raman spectral data preprocessing is specifically: applying the adaptive iterative reweighted penalized least squares method to subtract the spectral baseline from the obtained Raman spectrum, remove noise, and retain the effective information of the Raman spectrum; the feature extraction is specifically: using the peak search algorithm to screen out the characteristic peaks at specific wavenumber positions from the preprocessed spectral data; the classification recognition is specifically: matching the spectral data to the database through the search algorithm for identification, and then performing qualitative or quantitative analysis on unknown organic solvent samples; the database contains the spectral characteristics of known compounds and their physicochemical property information;

[0035] The instrument housing includes an aluminum alloy plate 1, a cover plate 17, a panel 2 and a partition 3, and the panel 2, the partition 3 and the cover plate 17 are all made of acrylic material; the panels 2 on all sides are fixed to the aluminum alloy plate 1 at the bottom by screws, and the partition 3 is vertically placed in the middle of the panel 2, and is at the same distance of 18 cm from the panels 2 on both sides, and is fixed to the panel 2 by a slide rail; a slide rail is provided at the upper end of the panel 2, and the cover plate 17 is covered on the panel 2 by the slide rail, and the cover plate 17 can be moved along the slide rail to realize the opening and closing of the instrument housing, which is convenient for the replacement and maintenance of internal components. In this embodiment, the aluminum alloy plate is 45cm×30cm, the cover plate is 36cm×25cm, and the panel and the partition are 25cm×10cm;

[0036] The partition 3 is provided with a light hole 22 with a diameter of 1 cm, which facilitates the Raman reflection signal to be transmitted from the left optical path of the partition to the right optical path, and can filter out the stray light refracted in the instrument. The enclosure 2 is provided with an inlet 20, an outlet 21, and an opening for the optical fiber coupler;

[0037] The aluminum alloy plate 1 is provided with lifting handles 19 on both sides, and the lifting handles 19 are fixed to the aluminum alloy plate 1 by screws;

[0038] The Raman spectrum excitation detection optical path includes a laser 7, an objective lens 9, a converging lens 11, a beam splitter prism 8, a filter 10, an optical micropore 12, a first reflector 13, a second reflector 14, a grating 15, a CCD module 16 and a fiber coupler 26; wherein the fiber coupler 26 is fixed in the fiber coupler opening of the enclosure, and the laser 7, the objective lens 9, the converging lens 11, the beam splitter prism 8, the filter 10, the optical micropore 12, the first reflector 13, the second reflector 14, the grating 15, the CCD module 16 and the fiber coupler 26. The base of the CD module 16 is fixed to the aluminum alloy plate 1 by screws; the optical fiber coupler 26, the beam splitter prism 8, and the laser 7 are sequentially placed on the same straight line; the microfluidic chip 6, the objective lens 9, the beam splitter prism 8, the light hole 22 on the partition, the filter 10, the converging lens 11, the optical micropore 12, and the first reflector 13 are sequentially placed on the same straight line; the first reflector 13, the second reflector 14, and the grating 15 are arranged at an angle of 45° to the incident light; and the CCD module 16 is arranged at an angle of 90° to the incident light;

[0039] The power of the laser 7 is 100 mW, and it is used to generate 532 nm green laser. The CCD module 16 adopts Sony ILX511, and is connected to the host computer through a data cable via a USB interface 25 fixed to the instrument housing, which can not only power the CCD module, but also transmit the received spectral signal to the spectral analysis software in the host computer for processing.

[0040] The peristaltic pump 4 is connected to two hoses, one of which is connected to the microfluidic chip, and the other is passed through the sampling port and placed outside the instrument to hold a sampling tube containing an organic solvent; the regulating knob 24 of the peristaltic pump is fixed to the instrument housing and is used to adjust the sample flux during detection;

[0041] The positioning platform 5 is composed of a manually adjustable XY two-dimensional micro-displacement platform and a chip fixture, which is fixed by screws; the chip fixture is suitable for microfluidic chips with a size not exceeding 25mm×75mm.

[0042] The power supply 18 is used to power the peristaltic pump and the laser, and a power switch 23 of the power supply is fixed at the bottom of the instrument housing.

[0043] Embodiment 1: As the specification sheet Figure 1 , Figure 2 As shown, an organic solvent Raman spectroscopy detection system integrated with a microfluidic chip includes a Raman spectroscopy excitation-detection optical path, a positioning platform 5, a peristaltic pump 4, a mobile power supply 18, an instrument housing and spectroscopy analysis software. When performing Raman spectrum detection, laser light is generated by a laser 7 and focused into a channel in a microfluidic chip 6 through a beam splitter prism 8 and an objective lens 9; the organic solvent to be detected enters the microfluidic chip from an inlet 20 driven by a peristaltic pump, and the positioning table for fixing the microfluidic chip is pre-adjusted so that the excitation light emitted by the laser is accurately focused on the sample in the microfluidic chip after passing through an optical prism and an objective lens; the Raman signal generated by the excited organic solvent is collected by the objective lens 9, passes through the beam splitter prism 8, and then enters the filter 10 on the right through a light hole 22 reserved in the partition 3 to filter out Rayleigh scattered light, and then passes through a converging lens 11 and an optical micropore 12 to irradiate the first reflector 13, and the reflected light passes through a grating 15 to be dispersed into a series of light beams of different wavelengths to form a spectrum, and the spectrum passes through a second reflector 14 and is received by a CCD detection module 16 and transmitted to the spectrum analysis software in the host computer for processing, thereby realizing Raman spectrum detection of the organic solvent.

[0044] Example 2: Compared with the organic solvent Raman spectroscopy detection system integrated with a microfluidic chip described in Example 1, the difference of Example 2 is that it provides a detection method for external Raman reflection signals.

[0045] As the instruction manual Figure 2 As shown, the external Raman reflection signal can be introduced into the spectroscopic prism 8 inside the instrument through the optical fiber coupler 26. After passing through the spectroscopic prism 8, the Raman signal enters the right detection optical path through the light-through hole 22 reserved in the partition 3. The subsequent propagation optical path is consistent with the right optical path of the partition 3 in Example 1. Finally, the spectral signal is received by the CCD module 16 and transmitted to the host computer for processing and analysis, thereby completing the detection of samples outside the instrument, greatly expanding the application scope of the system.

[0046] Embodiment 3: As the specification sheet Figure 3 As shown in the figure, methanol, ethanol, toluene and acetone solutions are respectively passed into the microfluidic chip for Raman spectroscopy detection. After data processing, the spectral signal can be compared with the spectrum in the database to analyze the type of unknown organic solvent. Figure 4 As shown in the figure, ethanol solutions of different concentrations are passed through the microfluidic chip for Raman spectroscopy detection to obtain spectral signals; as shown in the attached manual Figure 5 As shown in the figure, the linear relationship between the ethanol concentration detected by Raman spectroscopy and the actual concentration is as high as 96.3%. These data show that this system can effectively complete the qualitative and quantitative analysis of organic solvent samples with high resolution and sensitivity.

[0047] The above description is only a preferred embodiment of the present disclosure and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the embodiments of the present disclosure is not limited to the technical solutions formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the above-mentioned inventive concept. For example, the above-mentioned features are replaced with the technical features with similar functions disclosed in the embodiments of the present disclosure (but not limited to) to form a technical solution.

Claims

1. An organic solvent Raman spectroscopy detection system integrated with a microfluidic chip, characterized in that: It includes Raman spectroscopy excitation and detection optical path, microfluidic chip, positioning stage, peristaltic pump, power supply, instrument housing and spectral analysis software; The microfluidic chip is formed by bonding polydimethylsiloxane and a glass slide after plasma treatment; The instrument housing includes an aluminum alloy plate, a cover plate, a panel and a partition plate, and the panel, partition plate and cover plate are all made of acrylic material; the panels on all sides are fixed to the aluminum alloy plate at the bottom by screws, and the partition plate is vertically placed in the middle of the panel, with the same distance from the panels on both sides, and is fixed to the panel by a slide rail; a slide rail is provided at the upper end of the panel, and the cover plate is covered on the panel by the slide rail; The partition is provided with a light-through hole; the enclosure is provided with a sample inlet, a sample outlet, and a fiber optic coupler opening; The aluminum alloy plate is provided with lifting handles on both sides, and the lifting handles are fixed to the aluminum alloy plate by screws; The laser power is 100mW, which is used to generate 532nm green laser; the CCD module is connected to the host computer through a USB interface fixed to the instrument housing through a data cable; The peristaltic pump is connected to two hoses, one of which is connected to the microfluidic chip, and the other passes through the sampling port and is placed outside the instrument in a sampling tube containing an organic solvent; an adjustment button of the peristaltic pump is fixed to the instrument housing and is used to adjust the sample flux during detection.

2. The organic solvent Raman spectroscopy detection system integrated with a microfluidic chip according to claim 1, characterized in that: The Raman spectrum excitation detection optical path includes a laser, an objective lens, a converging lens, a beam splitter, a filter, an optical micropore, a first reflector, a second reflector, a grating, a CCD module and a fiber coupler; wherein the fiber coupler is fixed in the fiber coupler opening of the enclosure, and the bases of the laser, the objective lens, the converging lens, the beam splitter, the filter, the optical micropore, the first reflector, the second reflector, the grating and the CCD module are fixed to the aluminum alloy plate by screws; the fiber coupler, the beam splitter and the laser are placed in the same straight line in sequence, and the microfluidic chip and the objective lens, the beam splitter, the light hole on the partition, the filter, the converging lens, the optical micropore and the first reflector are placed in the same straight line in sequence, the first reflector, the second reflector and the grating are arranged at a 45° angle to the incident light, and the CCD module is arranged at a 90° angle to the incident light.

3. The organic solvent Raman spectroscopy detection system integrated with a microfluidic chip according to claim 1, characterized in that: The positioning platform is composed of a manually adjustable XY two-dimensional micro-displacement platform and a chip fixture, which are fixed by screws.

4. The organic solvent Raman spectroscopy detection system integrated with a microfluidic chip according to claim 1, characterized in that: The power supply is used to power the peristaltic pump and the laser, and the main power switch of the power supply is fixed at the bottom of the instrument housing.

5. The organic solvent Raman spectroscopy detection system integrated with a microfluidic chip according to claim 1, characterized in that: The spectral analysis software includes Raman spectral data preprocessing, feature extraction and classification recognition; the Raman spectral data preprocessing is specifically: applying the adaptive iterative reweighted penalized least squares method to subtract the spectral baseline from the obtained Raman spectrum, remove noise, and retain the effective information of the Raman spectrum; the feature extraction is specifically: using the peak search algorithm to screen out the characteristic peaks at specific wavenumber positions from the preprocessed spectral data; the classification recognition is specifically: matching the spectral data to the database through a search algorithm for identification, and then performing qualitative or quantitative analysis on unknown organic solvent samples; the database contains the spectral characteristics of known compounds and their physicochemical property information.

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