High-throughput detection method and system for heavy metal ions

Abstract

The invention relates to the technical field of heavy metal ion detection, in particular to a high-throughput detection method and system.The acquisition process of dark field images is determined according to the detection precision of a miniaturized dark field system, when the detection precision is high, a common sensor is designed to achieve dark field image acquisition, and when the detection precision is low, the common sensor is designed to achieve high-throughput detection. A more sensitive sensor is designed to realize acquisition of dark field images, so that the detection accuracy of heavy metal ions can be effectively improved; meanwhile, the multi-channel micro-fluidic chip structure provided by the invention can greatly improve the detection efficiency and reliability while realizing high throughput.

Description

Technical Field

[0001] The present invention relates to the technical field of heavy metal ion detection, and in particular to a high-throughput detection method and system for heavy metal ions. Background Art

[0002] At present, there are many detection technologies for heavy metal ions in water environment. From the perspective of detection technology principles, they are mainly divided into spectral detection technology, electrochemical detection technology, optical detection technology and other new detection technologies. Spectral detection is mainly based on atomic spectroscopy, including atomic absorption spectroscopy, atomic emission spectroscopy, inductively coupled plasma atomic emission spectroscopy and other methods related to electron energy spectrum. Spectroscopy is currently the most reliable mainstream method for detecting heavy metal ions, but there are always limitations such as the detection instrument is not easy to carry, the price is high, the pre-treatment process is complicated, the procedure is cumbersome and time-consuming, which makes it difficult to meet the needs of rapid on-site detection of actual samples. Electrochemical methods include amperometry, voltammetry, potentiometry, etc., which have the advantages of high sensitivity, simple operation and easy miniaturization, but it is difficult to detect trace heavy metal ions. Optical detection technologies include laser induced breakdown spectroscopy, optical colorimetry and fluorescence detection. The advantages of laser induced breakdown spectroscopy are that it can perform multi-element analysis, fast response speed and no sample pretreatment, but under high pulse energy, the detection of volatile heavy metals faces great challenges. Optical colorimetry and fluorescence detection methods based on nanoparticles are simple and fast, but have high detection limits and relatively poor repeatability. Other new detection methods include enzyme inhibition, immunoassay, and biosensor methods, most of which can only perform qualitative or semi-quantitative detection of heavy metals. The detection accuracy, repeatability, and reliability are still somewhat behind traditional detection methods. The above reasons have led to a serious lack of efficiency in on-site detection of heavy metal ions, and the usual detection methods can only detect one type of heavy metal ion. There are still great challenges in achieving high-throughput detection of multiple heavy metal ions. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a high-throughput detection method and system for heavy metal ions to improve the accuracy and detection speed of heavy metal ion detection.

[0004] The present invention provides a high-throughput detection method for heavy metal ions, comprising the following steps: S1: dark field image acquisition of the sample to be tested; A data acquisition system of a high-throughput dark-field biochemical sensing system is used to acquire dark-field images of a sample to be tested, wherein the data acquisition system of the high-throughput dark-field biochemical sensing system includes a miniaturized dark-field system and a multi-channel microfluidic chip; when acquiring dark-field images of the sample to be tested, an acquisition process of the dark-field image is determined according to the detection accuracy of the miniaturized dark-field system; if the minimum spectral red shift detected by the miniaturized dark-field system is greater than a preset threshold, a first dark-field image acquisition process is used, otherwise a second dark-field image acquisition process is used; S2: performing data preprocessing operation on the dark field image; S3: performing image processing operations on the pre-processed dark field image, thereby realizing the concentration detection of metal ions.

[0005] Preferably, in S1, the miniaturized dark field system comprises a dark field microscope, a dark field condenser, an intelligent terminal and a modulated monochromatic light source; wherein the modulated monochromatic light source is a 250W adjustable halogen lamp light source, and the white light source emitted by the halogen lamp is modulated to obtain a monochromatic incident light source with continuous wavelength modulation; the monochromatic incident light source is input into the dark field microscope, and after being focused by the dark field condenser, it is focused on the multi-channel microfluidic chip, and the scattered light of the nanoparticles of the sample to be tested in the microfluidic chip can be directly observed by the naked eye through the eyepiece of the dark field microscope, and then recorded in the form of an image through the intelligent terminal to form a dark field image; Preferably, the multi-channel microfluidic chip is made of a glass substrate and a PDMS film, and four parallel observation areas are designed on the multi-channel microfluidic chip. The single plasma nanosensor is fixed in advance on the substrate of the observation area through four probe inlets. The sample to be tested enters four different areas in the reflection pool through the sample inlet via the microchannel. The four areas are modified with different ligand probes, thereby realizing the acquisition of dark field images.

[0006] Preferably, the single plasmon nanosensor is composed of gold nanoparticles with stable chemical properties and good biocompatibility, and the single plasmon nanosensor is obtained by modifying the surface of the gold nanoparticles with specific ligand probes that can recognize heavy metal ions.

[0007] Preferably, the single plasmonic nanosensor in each observation area is modified with a different ligand probe.

[0008] Preferably, the sensing principle of the single plasma nanosensor is that the scattering spectrum of gold nanoparticles shifts under the action of the binding of heavy metal ions with specific probes.

[0009] Preferably, the first dark field image acquisition process is: Sa.1: A single plasmon nanosensor is obtained by modifying the surface of gold nanoparticles with specific ligand probes that can recognize heavy metal ions; Sa.2: The first dark field image is collected by the single plasma nanosensor.

[0010] Preferably, the second image acquisition process is: Sb.1: A specific ligand probe capable of recognizing heavy metal ions is modified on the surface of gold nanoparticles; Sb.2: Add nanospheres for signal amplification. Gold nanoparticles and nanospheres form a core-satellite nanostructure under the action of metal ions, thereby obtaining a single plasma nanosensor. Sb.3: Collecting the second dark field image through the single plasma nanosensor.

[0011] Preferably, in S2, an intelligent terminal of a high-throughput dark-field biochemical sensing system is used to perform data preprocessing operations on the dark-field image.

[0012] Preferably, S3 specifically comprises: determining the center coordinates of the image bright spot in the dark field image, then calculating the brightness value of the image bright spot, traversing the entire set of the dark field images, using the Lorentz function to perform spectral fitting on the image bright spot, calculating the resonant wavelength, and calculating the spectral offset according to the resonant wavelength to realize the detection of heavy metal ion concentration.

[0013] According to another aspect of the present invention, a high-throughput detection system for heavy metal ions is provided, wherein the system adopts any one of the high-throughput detection methods for heavy metal ions described above, and the system comprises: A data acquisition system, used for acquiring dark field images of the sample to be tested; An image preprocessing system, used for performing data preprocessing operations on the dark field image; The concentration detection system is used to perform image processing operations on the pre-processed dark field image, thereby realizing the concentration detection of heavy metal ions.

[0014] The embodiments of the present invention have the following technical effects: The present invention determines the acquisition process of the dark field image according to the detection accuracy of the miniaturized dark field system. When the detection accuracy is high, an ordinary sensor is designed to realize the acquisition of the dark field image. When the detection accuracy is low, a more sensitive sensor is designed to realize the acquisition of the dark field image, which can effectively improve the detection accuracy of heavy metal ions.

[0015] The multi-channel microfluidic chip structure provided by the present invention can greatly improve the detection efficiency and reliability while achieving high throughput. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 is a structural diagram of a high-throughput detection method for heavy metal ions provided in Example 1 of the present invention; Figure 2 It is a schematic diagram of the structure of the multi-channel microfluidic chip provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0019] Embodiment 1, Figure 1 1 is a flow chart of a high-throughput detection method for heavy metal ions provided in Example 1 of the present invention. Figure 1 , specifically including the following steps: S1: dark field image acquisition of the sample to be tested; A data acquisition system of a high-throughput dark-field biochemical sensing system is used to acquire dark-field images of the sample to be tested, wherein the data acquisition system of the high-throughput dark-field biochemical sensing system includes a miniaturized dark-field system and a multi-channel microfluidic chip; The miniaturized dark field system includes a dark field microscope, a dark field condenser, an intelligent terminal and a modulated monochromatic light source; wherein the modulated monochromatic light source is a 250W adjustable halogen lamp light source, and the white light source emitted by the halogen lamp is modulated to obtain a monochromatic incident light source with continuous wavelength modulation; the monochromatic incident light source is input into the dark field microscope, and after being focused by the dark field condenser, it is focused on the multi-channel microfluidic chip, and the scattered light of the nanoparticles of the sample to be tested in the microfluidic chip can be directly observed by the naked eye through the eyepiece of the dark field microscope, and then recorded in the form of an image through the intelligent terminal to form a dark field image; It is worth noting that, since the present embodiment adopts an adjustable halogen lamp light source, the dark field image is a dark field image of different incident light wavelengths; The multi-channel microfluidic chip can integrate almost all experimental steps such as nanoparticle fixation, modification and spectral detection into one chip, and has the advantages of low sample consumption, short reaction time and parallel operation, and is the key to achieving high-throughput parallel detection. Figure 2 The schematic diagram of the structure of the multi-channel microfluidic chip provided in this embodiment is shown in FIG. Figure 2 In order to ensure the light transmittance of the transmission dark field structure, the multi-channel microfluidic chip is made of a glass substrate and a PDMS film as thin as possible. Four parallel observation areas are designed on the multi-channel microfluidic chip. The single plasma nanosensor is fixed on the substrate of the observation area in advance through four probe inlets. The sample to be tested enters four different areas in the reflection pool through the sample inlet through the microchannel. The four areas are modified with different ligand probes to achieve dark field image observation. Finally, the sample to be tested flows out through the sample liquid outlet. The multi-channel microfluidic chip structure set in this embodiment can greatly improve the detection efficiency and reliability while achieving high throughput. The single plasma nanosensor is composed of gold nanoparticles with stable chemical properties and good biocompatibility. The single plasma nanosensor is obtained by modifying the surface of the gold nanoparticles with specific ligand probes that can recognize heavy metal ions. The sensing principle of the single plasma nanosensor is that the scattering spectrum of the gold nanoparticles shifts under the action of the combination of heavy metal ions and specific probes. In this embodiment, for example, the oligonucleotide base sequence of TT mismatch that can specifically detect mercury ions is as follows: oligonucleotide 1 is [5'SH (CH2) 6TCAGTTTGGC3'], and its TT mismatch base sequence oligonucleotide 2 is [5'SH (CH2) -6GCCTTTCTGA3']. Taking the detection of mercury ions by this probe as an example, the oligonucleotide single strand is first modified on the surface of the gold nanorod by thiol, and oligonucleotide 1 and oligonucleotide 2 form T-Hg2+-T mismatch base hybridization under the action of mercury ions, so that the gold nanorod and the small nanosphere (generally less than 10nm in diameter) form a gold nanocore-satellite structure, and the scattering spectrum is red-shifted. In contrast, in the absence of mercury ions, a hybrid double strand cannot be formed, and a spectral red shift cannot be generated. In this way, the spectral signal changes of the nanoparticles in the presence and absence of mercury ions can be observed in a dark field system, and the concentration of mercury ions can be quantified by calculating the spectral offset.

[0020] It is worth emphasizing that when the dark field image of the sample to be tested is collected, the dark field image collection process is determined according to the detection accuracy of the miniaturized dark field system; if the minimum spectral red shift detected by the miniaturized dark field system is greater than a preset threshold, the first dark field image collection process is adopted, otherwise the second dark field image collection process is adopted; Wherein, the first dark field image acquisition process is: Sa.1: A single plasmon nanosensor is obtained by modifying the surface of gold nanoparticles with specific ligand probes that can recognize heavy metal ions; Sa.2: collecting the first dark field image by the single plasma nanosensor; Wherein, the second image acquisition process is: Sb.1: A specific ligand probe capable of recognizing heavy metal ions is modified on the surface of gold nanoparticles; Sb.2: Add nanospheres for signal amplification. Gold nanoparticles and nanospheres form a core-satellite nanostructure under the action of metal ions, thereby obtaining a single plasma nanosensor. Sb.3: collecting the second dark field image through the single plasma nanosensor; In this step, the dark field image acquisition process is determined according to the detection accuracy of the miniaturized dark field system. When the detection accuracy is high, an ordinary sensor is designed to realize dark field image acquisition. When the detection accuracy is low, a more sensitive sensor is designed to realize dark field image acquisition, which can effectively improve the detection accuracy of heavy metal ions.

[0021] In this step, four parallel observation areas are designed on the multi-channel microfluidic chip. Therefore, the single plasma nanosensor in each observation area is modified with different ligand probes to achieve concentration detection of multiple heavy metal ions.

[0022] S2: performing data preprocessing operation on the dark field image; Wherein, an intelligent terminal of a high-throughput dark-field biochemical sensing system is used to perform data preprocessing operations on the dark-field image; The data preprocessing operation for the dark field image is specifically: processing the dark field image by matlab to achieve spectrum reconstruction of the nanoparticles.

[0023] S3: performing image processing operations on the pre-processed dark field image, thereby realizing the concentration detection of metal ions.

[0024] Among them, S3 specifically includes: determining the center coordinates of the image bright spot in the dark field image, then calculating the brightness value of the image bright spot, traversing the entire set of the dark field images, using the Lorentz function to perform spectral fitting on the image bright spot, calculating the resonant wavelength, and calculating the spectral offset according to the resonant wavelength to realize the detection of heavy metal ion concentration.

[0025] Embodiment 2, the present invention further provides a high-throughput detection system for heavy metal ions, the system adopts a high-throughput detection method for heavy metal ions described in any one of Embodiment 1, the system comprising: A data acquisition system, used for acquiring dark field images of the sample to be tested; An image preprocessing system, used for performing data preprocessing operations on the dark field image; The concentration detection system is used to perform image processing operations on the pre-processed dark field image, thereby realizing the concentration detection of heavy metal ions.

[0026] Embodiment 3, the present invention also provides an electronic device, including one or more processors and a memory. The processor may be a central processing unit (CPU) or other forms of processing units with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions.

[0027] The memory may include one or more computer program products, and the computer program product may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory (cache), etc. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor may run the program instructions to implement a high-throughput detection method for heavy metal ions and / or other desired functions of any embodiment of the present application described above. Various contents such as initial external parameters, thresholds, etc. may also be stored in the computer-readable storage medium.

[0028] In one example, the electronic device may further include: an input device and an output device, and these components are interconnected through a bus system and / or other forms of connection mechanisms (not shown). The input device may include, for example, a keyboard, a mouse, etc. The output device may output various information to the outside, including early warning information, braking force, etc. The output device may include, for example, a display, a speaker, a printer, a communication network and a remote output device connected thereto, etc.

[0029] Of course, for the sake of simplicity, components such as buses, input / output interfaces, etc. are omitted. In addition, the electronic device may further include any other appropriate components according to specific application conditions.

[0030] In addition to the above-mentioned methods and devices, the embodiments of the present application may also be a computer program product, which includes computer program instructions, which, when executed by a processor, enable the processor to implement the functions of a high-throughput detection method for heavy metal ions provided in any embodiment of the present application.

[0031] The computer program product may be written in any combination of one or more programming languages ​​to write program codes for performing the operations of the embodiments of the present application, including object-oriented programming languages, such as Java, C++, etc., and conventional procedural programming languages, such as "C" language or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as an independent software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0032] In addition, an embodiment of the present application may also be a computer-readable storage medium on which computer program instructions are stored. When the computer program instructions are executed by a processor, the processor implements the function of a high-throughput detection method for heavy metal ions provided in any embodiment of the present application.

[0033] The computer readable storage medium can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can include, for example, but is not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0034] It should be noted that the terms used in the present invention are only for describing specific embodiments, rather than limiting the scope of the present application. As shown in the present specification, unless the context clearly indicates an exception, the words "one", "a", "a kind of" and / or "the" do not specifically refer to the singular, but may also include the plural. The terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method or device. In the absence of more restrictions, the elements defined by the sentence "include one..." do not exclude the presence of other identical elements in the process, method or device including the elements.

[0035] It should also be noted that the orientations or positional relationships indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention.

Claims

1. A high-throughput detection method for heavy metal ions, characterized in that: The following steps are involved: S1: dark field image acquisition of the sample to be tested; A data acquisition system of a high-throughput dark-field biochemical sensing system is used to acquire dark-field images of the sample to be tested, wherein the data acquisition system of the high-throughput dark-field biochemical sensing system includes a miniaturized dark-field system and a multi-channel microfluidic chip; when acquiring dark-field images of the sample to be tested, an acquisition process of the dark-field images is determined according to the detection accuracy of the miniaturized dark-field system; If the minimum spectral red shift detected by the miniaturized dark field system is greater than a preset threshold, the first dark field image acquisition process is adopted, otherwise the second dark field image acquisition process is adopted; S2: performing data preprocessing operation on the dark field image; S3: performing image processing operations on the pre-processed dark field image, thereby realizing the concentration detection of metal ions.

2. The high-throughput detection method for heavy metal ions according to claim 1, characterized in that: In S1, the miniaturized dark field system includes a dark field microscope, a dark field condenser, an intelligent terminal and a modulated monochromatic light source; wherein the modulated monochromatic light source is a 250W adjustable halogen lamp light source, and the white light source emitted by the halogen lamp is modulated to obtain a monochromatic incident light source with continuous wavelength modulation; the monochromatic incident light source is input into the dark field microscope, and after being focused by the dark field condenser, it is focused on the multi-channel microfluidic chip, and the scattered light of the nanoparticles of the sample to be tested in the microfluidic chip can be directly observed by the naked eye through the eyepiece of the dark field microscope, and then recorded in the form of an image through the intelligent terminal to form a dark field image.

3. The high-throughput detection method for heavy metal ions according to claim 2, characterized in that: The multi-channel microfluidic chip is made of a glass substrate and a PDMS film. Four parallel observation areas are designed on the multi-channel microfluidic chip. A single plasma nanosensor is fixed in advance on the substrate of the observation area through four probe inlets. The sample to be tested enters four different areas in the reflection pool through the sample inlet via a microchannel. The four areas are modified with different ligand probes, thereby realizing the collection of dark field images.

4. The high-throughput detection method for heavy metal ions according to claim 3, characterized in that: The single plasma nanosensor is composed of gold nanoparticles with stable chemical properties and good biocompatibility. The single plasma nanosensor is obtained by modifying the surface of the gold nanoparticles with specific ligand probes capable of identifying heavy metal ions.

5. The high-throughput detection method for heavy metal ions according to claim 4, characterized in that: A single plasmonic nanosensor in each observation area is modified with a different ligand probe.

6. The high-throughput detection method for heavy metal ions according to claim 5, characterized in that: The sensing principle of the single plasma nanosensor is that the scattering spectrum of the gold nanoparticles shifts under the action of the combination of heavy metal ions and specific probes.

7. The high-throughput detection method for heavy metal ions according to claim 1, characterized in that: The first dark field image acquisition process is as follows: Sa.1: A single plasmon nanosensor is obtained by modifying the surface of gold nanoparticles with specific ligand probes that can recognize heavy metal ions; Sa.2: The first dark field image is collected by the single plasma nanosensor.

8. The high-throughput detection method for heavy metal ions according to claim 7, characterized in that: The second dark field image acquisition process is as follows: Sb.1: A specific ligand probe capable of recognizing heavy metal ions is modified on the surface of gold nanoparticles; Sb.2: Add nanospheres to amplify the signal. Gold nanoparticles and nanospheres form a core-satellite nanostructure under the action of metal ions, thereby obtaining a single plasma nanosensor. Sb.3: Collecting the second dark field image through the single plasma nanosensor.

9. The high-throughput detection method for heavy metal ions according to claim 1, characterized in that: The S2 specifically includes: using an intelligent terminal of a high-throughput dark-field biochemical sensing system to perform data preprocessing operations on the dark-field image; the S3 specifically includes: determining the center coordinates of the image bright spot in the dark-field image, then calculating the brightness value of the image bright spot, traversing the entire set of the dark-field images, using the Lorentz function to perform spectral fitting on the image bright spot, calculating the resonant wavelength, and calculating the spectral offset according to the resonant wavelength to achieve the detection of heavy metal ion concentration.

10. A high-throughput detection system for heavy metal ions, characterized in that: The system adopts the high-throughput detection method for heavy metal ions according to any one of claims 1 to 9, and the system comprises: A data acquisition system, used for acquiring dark field images of the sample to be tested; An image preprocessing system, used for performing data preprocessing operations on the dark field image; The concentration detection system is used to perform image processing operations on the pre-processed dark field image, thereby realizing the concentration detection of heavy metal ions.

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