Portable multichannel detection system and application thereof

Abstract

The invention provides a portable multi-channel detection system and an application thereof. The detection system comprises a nanometer photon chip and a detection probe, and the nanometer photon chip comprises a one-dimensional nanometer structure and biomolecules; the biomolecules are modified on the one-dimensional nano structure; the detection probe comprises a target detection object and a dielectric nano-material. According to the method, a fluorescent marker is not needed, and complex sample treatment steps and interference of background fluorescence are reduced. The invention provides a simple and convenient way for portable rapid detection of biomarkers, and has important significance in the aspects of early diagnosis of diseases, curative effect judgment, postoperative monitoring and the like, so that home detection of various diseases becomes possible.

Description

Technical Field

[0001] The present invention relates to the technical field of optical nanoimaging and biomarker detection, and particularly relates to a detection system for portable multi-channel detection and its application. Background Art

[0002] Proteins are macromolecules that participate in important biological processes such as genomic information replication, transcriptional regulation, signal transduction, and catalytic reactions. The misfolding, mutation, overexpression, or underexpression of many proteins is closely related to many diseases and can be used as drug targets or biomarkers for disease detection, efficacy diagnosis, and postoperative monitoring. Therefore, the detection and quantification of proteins are extremely important. However, existing protein detection methods all have their own problems: Conventional techniques such as enzyme-linked immunosorbent assay, Western blotting, and lateral flow immunoassay are widely used clinically, but they have low sensitivity and cannot detect many important proteins present at low concentrations; Fluorescence detection methods have intuitive results, but require professional fluorescence observation equipment and are subject to interference factors such as background fluorescence; Nanopore technology has extremely high detection sensitivity and can achieve ultrasensitive detection of single proteins, but requires high professional knowledge. In recent years, with the continuous development of nanomanufacturing technology, biosensor devices based on nanophotonic structures have provided great opportunities to overcome the above limitations. For example, surface plasmon sensors, surface-enhanced Raman scattering technology, photonic crystal sensors, colorimetry, etc. Among them, surface plasmon resonance and surface-enhanced Raman scattering methods have relatively high sensitivity, but the detection equipment is complex and expensive; Photonic crystal sensors can detect multiple biomarkers simultaneously, but require special fluorescent probes to label the target analyte; The colorimetric detection method based on colloidal nanoparticles is simple and visual, but has limited sensitivity and is difficult to achieve quantitative detection. Therefore, there is an urgent need for a new detection technology to achieve simple, rapid, sensitive, portable, and high-throughput detection of protein biomarkers for early disease diagnosis and postoperative monitoring, which is of great significance for underdeveloped regions or people lacking professional detection equipment. Summary of the Invention

[0003] To solve the above technical problems, the present invention provides the following technical solutions:

[0004] A detection system, the detection system includes a nanophotonic chip and a detection probe, wherein,

[0005] The nanophotonic chip includes a one-dimensional nanostructure and a biomolecule; the biomolecule is modified on the one-dimensional nanostructure;

[0006] The detection probe includes a target analyte and a dielectric nanomaterial.

[0007] According to an embodiment of the present invention, the nanophotonic chip can specifically recognize a target analyte corresponding to the biomolecule.

[0008] According to an embodiment of the present invention, the target analyte is selected from at least one of proteins, nucleic acid molecules, etc., for example, proteins related to cardiovascular diseases, gastric cancer, and colorectal cancer; preferably at least one of immunoglobulin (IgG protein), microtubule-associated protein related to Alzheimer's disease (Tau protein), serum CEACAM1 protein, DNA, RNA, small molecules, etc.

[0009] According to an embodiment of the present invention, the biomolecule or the target analyte can be fluorescently labeled or not, independently of each other.

[0010] According to an embodiment of the present invention, the dielectric nanomaterial is selected from one, two, or more of silicon nanoparticles, selenium nanoparticles, and titanium dioxide nanoparticles, preferably selenium nanoparticles.

[0011] According to an embodiment of the present invention, the dielectric nanomaterial can also be surface-coated. Preferably, the surface-coating materials are, for example, polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), carboxymethyl chitosan (CMCS), and polyacrylamide (PAM). Exemplarily, the dielectric nanomaterial is selenium nanoparticles coated with PVP.

[0012] According to an embodiment of the present invention, the diameter of the dielectric nanomaterial is 100 - 600 nm, for example, 150 - 500 nm, and exemplarily 200 nm, 250 nm, 300 nm, 350 nm.

[0013] According to an embodiment of the present invention, when the detection probe is used, it is also optionally incubated.

[0014] According to an embodiment of the present invention, the target analyte and the dielectric nanomaterial are bound by chemical bonding or electrostatic adsorption.

[0015] According to an embodiment of the present invention, after the detection probe is dropped onto the nanophotonic chip shown, the target analyte specifically binds to the biomolecule. At the same time, the dielectric nanomaterial on the detection probe binds to the one-dimensional nanostructure. In the present invention, after the dielectric nanomaterial binds to the one-dimensional nanostructure, a color change distinguishable by the naked eye occurs in the one-dimensional nanostructure; or a color change image generated by the one-dimensional nanostructure can be obtained through image software such as Image J, and RGB analysis is performed on it to quantitatively characterize the change in color intensity before and after the binding of the detection probe and analyze the concentration of the target analyte.

[0016] According to an embodiment of the present invention, the biomolecule and the one-dimensional nanostructure can be connected by chemical bonding.

[0017] According to an embodiment of the present invention, the one-dimensional nanostructure contains nanoparticles, one-dimensional nanowires, one-dimensional nanorods or one-dimensional nanocylinders. Preferably, the nanoparticles have uniform sizes. Preferably, the one-dimensional nanostructure is self-assembled from nanoparticles with uniform sizes, one-dimensional nanowires, one-dimensional nanorods or one-dimensional nanocylinders.

[0018] According to an embodiment of the present invention, the nanoparticles can be spherical, cubic or rod-shaped nanoparticles.

[0019] According to an embodiment of the present invention, the diameter of the nanoparticles is 100 - 800 nm, such as 250 - 800 nm, and exemplary diameters are 250 nm, 400 nm, 500 nm, 750 nm.

[0020] According to an embodiment of the present invention, the material of the one-dimensional nanostructure is selected from polymer nanomaterials. Preferably, the polymer nanomaterials can be selected from polystyrene nanoparticles and / or poly(methyl methacrylate) nanoparticles. Exemplarily, the material of the one-dimensional nanostructure is modified or unmodified polystyrene nanomaterials.

[0021] According to an exemplary embodiment of the present invention, the one-dimensional nanostructure can be a one-dimensional chain-like structure; preferably, it is a one-dimensional chain-like structure self-assembled from modified or unmodified polystyrene nanoparticles.

[0022] According to an embodiment of the present invention, the one-dimensional nanostructure can generate two scattering peaks in the visible light region.

[0023] According to an embodiment of the present invention, the nanophotonic chip further includes a substrate, and the one-dimensional nanostructure is located on the surface of the substrate.

[0024] According to an embodiment of the present invention, the substrate can be selected from a silicon substrate, a glass substrate or a flexible polymer substrate.

[0025] Preferably, the substrate is selected from a lithography template. Exemplarily, the lithography template is a silicon pillar template, the height of the silicon pillar is 10 μm, the width of the silicon pillar is 10 μm, and the pitch of the silicon pillars is 10 μm.

[0026] According to an embodiment of the present invention, the method for preparing the nanophotonic chip includes the following steps: soaking the substrate containing the one-dimensional nanostructure in a mixed solution of NHS (N-hydroxysulfosuccinimide) and EDC (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride) to activate the carboxyl group; then soaking the substrate in a solution containing the biomolecule and incubating to obtain the nanophotonic chip.

[0027] According to an embodiment of the present invention, the one-dimensional nanostructure, the substrate, and the biomolecule all have the meanings as described above.

[0028] According to an embodiment of the present invention, the substrate containing the one-dimensional nanostructure can be obtained by dropping a suspension containing carboxyl-modified nanoparticles, nanowires, nanorods, or nanocylinders onto the substrate, and the one-dimensional nanostructure located on the surface of the substrate is obtained by self-assembly.

[0029] Preferably, after self-assembly, the nanophotonic chip can also be sintered. Further, the sintering temperature is above 100°C, for example, 110°C; the sintering time is above 30 min, for example, 35 min.

[0030] According to an embodiment of the present invention, in the mixed solution of NHS and EDC, the molar concentration ratio of NHS to EDC is 1:(2 - 5), for example, 1:4.

[0031] According to an embodiment of the present invention, the time for activating the carboxyl group is 0.2 - 3 hours, for example, 0.4 hours.

[0032] According to an embodiment of the present invention, after the carboxyl group is activated, the soaked substrate is washed. For example, the surface of the substrate is washed with a PBS buffer solution.

[0033] According to an embodiment of the present invention, the incubation time can be 1 - 4 hours, for example, 2 hours.

[0034] According to an embodiment of the present invention, the preparation method further includes blocking the incubated substrate, and / or optionally washing. Preferably, bovine serum albumin (BSA) solution is used to block the remaining active sites. Preferably, the concentration of the bovine serum albumin (BSA) solution is 10 mg / mL, and the blocking is carried out at room temperature of 20°C for 10 min. Preferably, the washing can be carried out by a method known in the art, for example, washing with a PBS buffer solution.

[0035] According to an exemplary embodiment of the present invention, in the detection system, the nanophotonic chip includes a substrate and a one-dimensional nanostructure with a biomolecule located on the surface layer of the substrate;

[0036] The one-dimensional nanostructure is a one-dimensional chain-like structure formed by self-assembly of modified or unmodified polystyrene nanoparticles;

[0037] In the detection probe, the dielectric nanomaterial is selected from selenium nanoparticles; the target analyte is selected from immunoglobulin (IgG protein), serum CEACAM1 protein, and microtubule-associated protein related to Alzheimer's disease (Tau protein).

[0038] The present invention also provides the application of the above detection system in the field of biological detection.

[0039] The present invention also provides a method for using the above detection system, and the specific steps are as follows:

[0040] (1) Incubate the target analyte with the dielectric nanomaterial to prepare a solution of the detection probe;

[0041] (2) After dropping the solution of the detection probe onto the nanophotonic chip, the target analyte on the detection probe recognizes and specifically binds to the biomolecule on the one-dimensional nanostructure. Meanwhile, the dielectric nanomaterial on the detection probe binds to the one-dimensional nanostructure;

[0042] (3) Under the illumination of a normally incident light source, obtain the changes in the optical signals of the nanophotonic chip before and after the specific binding respectively.

[0043] According to an embodiment of the present invention, in step (1), the concentration ratio of the target analyte to the dielectric nanomaterial is (1 - 100 ng / mL): 0.01 mg / mL.

[0044] According to an embodiment of the present invention, in step (2), the time for recognition and specific binding is at least 30 min, for example, 60 min.

[0045] According to an embodiment of the present invention, in step (3), the method for obtaining the change in the optical signal of the nanophotonic chip is specifically as follows: observe with the naked eye, or read the optical signal using an optical instrument. Preferably, reading the optical signal using an optical instrument is specifically as follows: use an optical microscope to read the optical signal A of the nanophotonic chip before the specific binding and the optical signal B of the nanophotonic chip after the specific binding respectively, and calculate the difference between the optical signal A and the optical signal B. Preferably, the optical microscope is an upright microscope, and the magnification of the objective lens is, for example, 100 times, and the resolution of the imaging camera is, for example, 16 million pixels.

[0046] According to an embodiment of the present invention, the method for using further includes: (4) Analyze the change in the optical signal, compare with the standard curve, and read the concentration of the target analyte.

[0047] According to an embodiment of the present invention, the standard curve can be obtained by a method known in the art. For example, prepare a standard solution of the target analyte (in the standard solution, the concentration of the target analyte is 1 pg / mL - 100 ng / mL, for example, 1 pg / mL, 10 pg / mL, 100 pg / mL, 1 ng / mL, 10 ng / mL, 100 ng / mL), measure the changes in the optical signals of the standard solutions respectively, and then plot the standard curve.

[0048] Beneficial effects

[0049] The detection system of the present invention realizes label-free, portable, visual, and high-throughput detection of biomarkers such as proteins. The detection method is simple, the detection device is portable, and the detection is fast and sensitive. The present invention does not require the aid of complex instrument equipment or professional data analysis software. Only an ordinary optical microscope is used to complete the home detection of patients. This is of great significance for patients in remote areas or lacking professional knowledge. Taking the cancer biomarker CEACAM1 as an example, the present invention proves that the portable detection of CEACAM1 protein in the serum of cancer patients is realized by using the detection system of the present invention.

[0050] Based on the one-dimensional nanostructure, after specifically adsorbing the detection probe containing the target analyte (such as selenium nanoparticles containing the target analyte), its reflection signal changes significantly. After imaging with a camera, the detection result can be observed with the naked eye without the aid of any complex detection instruments and analysis software.

[0051] Compared with other detection methods for protein biomarkers, the present invention only requires dozens of microliters of detection samples to give the detection result. The sample consumption is small and no complex instrument equipment and professional data processing software are needed. The detection result is imaged by an optical microscope, and the result can be known with the naked eye, which is simple and convenient. The present invention does not require the aid of fluorescent labels, reducing the complex sample processing steps and the interference of background fluorescence. The present invention provides a simple method for the portable and rapid detection of biomarkers, which is of great significance in the directions of early disease diagnosis, curative effect judgment, postoperative monitoring, etc., making it possible to perform home detection of various diseases. Brief description of the drawings

[0052] Figure 1 It is a schematic diagram of the process of using a nanophotonic chip for multi-channel detection of protein biomarkers.

[0053] Figure 2 It is a one-dimensional nanostructure chip. The left side is the reflected light signal collected by the camera under bright-field light source, and the right side is the change in color intensity in different channels analyzed by Image J software; among them, the scale bar length is 20 μm.

[0054] Figure 3 It is an optical photograph of the nanochip for detecting CEACAM1 protein and the analysis result by Image J software; among them, the scale bar length is 2 μm.

[0055] Figure 4 It is the analysis result by Image J software of the nanochip for detecting multiple proteins.

[0056] Figure 5It is the quantitative detection result of CEACAM1. After adding proteins with different concentrations, the optical images of one-dimensional nanostructures and the optical signal intensity values; among them, the scale bar length is 3 μm.

[0057] Figure 6 It is the TEM image of the PVP-coated selenium nanoparticles obtained in Preparation Example 1. Detailed implementation manners

[0058] The technical solutions of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to illustrate and explain the present invention exemplarily, and should not be construed as limiting the protection scope of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0059] Unless otherwise specified, the raw materials and reagents used in the following embodiments are all commercially available products, or can be prepared by known methods.

[0060] As Figure 1 shown, the schematic diagram of the process of using the nanophotonic chip prepared by the present invention for multi-channel detection of protein markers. Among them, (Ⅰ) is specific antibody incubation, and the carboxyl group on the polystyrene nanoparticle can be connected to the amino group on the antibody by chemical bonding; (Ⅱ) is the preparation of selenium nanoprobes. Due to electrostatic interaction, selenium nanoparticles can bind to target proteins; (Ⅲ) is sample detection, and the solution of selenium nanoparticles and target proteins is mixed and then dropped on the detection chip; (Ⅳ) is the specific capture of selenium nanoprobes in the solution to be detected. The specific antibody on the one-dimensional nanostructure can specifically capture the selenium nanoprobes containing target proteins on the surface through antigen-antibody interaction; (Ⅴ) is optical direct detection. Through direct observation with an ordinary optical microscope, the visual detection of protein biomarkers can be achieved. The whole detection process is simple, fast, portable, and the detection result is intuitive.

[0061] Preparation Example 1

[0062] Prepare PVP-coated selenium nanoparticles: Prepare 100 mL of a 10 mg / mL PVP solution in a round-bottom flask, place it in a water bath at 90 °C, heat for 30 min to make the temperature inside and outside the system consistent, then pour in 1.5 g of glucose and 0.25 g of sodium selenite, and react for 40 min. After the reaction is completed, centrifuge and wash multiple times (for example, 3 times) to remove the excess PVP, and obtain PVP-coated selenium nanoparticles. As Figure 6 shown, its size is 250 nm, and PVP is uniformly coated on the surface of selenium with a thickness of 3 nm, improving the thermal stability of selenium nanoparticles.

[0063] Subsequently, it was diluted to obtain selenium nanoparticle solutions with concentrations of 0.01 mg / mL, 1 mg / mL, 3 mg / mL, 6 mg / mL, and 12 mg / mL respectively for standby.

[0064] Example 1

[0065] Prepare a mixed solution of selenium nanoparticles with a particle size of 250 nm and polystyrene nanoparticles with a particle size of 500 nm. Among them, the concentration of polystyrene nanoparticles is 3 mg / mL, and the concentrations of selenium nanoparticles are 0 mg / mL, 1 mg / mL, 3 mg / mL, 6 mg / mL, and 12 mg / mL respectively. Add 1 mg / mL of SDS to obtain different mixed solutions, namely mixed solutions i, ii, iii, iv, and v respectively. Drop 10 μL of the mixed solution on the silicon substrate respectively, then cover the patterned photolithography template, and maintain it at room temperature of 20 °C for 2 h. As the solution evaporates, the polystyrene nanoparticles and selenium nanoparticles are confined by the liquid bridge shrinkage, and one-dimensional nanostructures are assembled, denoted as chips i, ii, iii, iv, and v respectively, as shown in Figure 2 the left figure in the middle.

[0066] The inventors found that due to the particle size difference, the larger-sized polystyrene nanoparticles shrink first and become the central particles of the one-dimensional nanostructure, and the smaller-sized selenium nanoparticles are then confined by the droplets and assembled on both sides of the polystyrene nanochains. Then, the above chips were placed under a 100-fold objective lens of an optical microscope, and the reflected light signals of the one-dimensional nanostructures of the above different chips were photographed by a camera under a normal-incidence bright-field light source. As shown in Figure 2 the right figure in the middle, as the concentration of selenium nanoparticles changes, the reflected signal of the one-dimensional nanostructure changes significantly. Further analyze the intensities of the R, G, and B channels of the image with Image J software to obtain Figure 2 the histogram shown in the middle figure in the middle. The histogram shows that as the number of selenium nanoparticles increases, the colors of the three channels of the one-dimensional nanostructure change linearly. This method provides the possibility for label-free, portable, visual, and quantitative detection of multiple protein biomarkers.

[0067] Example 2

[0068] Preparation of a nanophotonic chip: Prepare a colloidal solution of polystyrene nanoparticles with a particle size of 500 nm and a concentration of 3 mg / mL, and add 1 mg / mL of sodium dodecyl sulfate (SDS) to the solution. Drop 10 μL of the colloidal solution containing SDS onto a silicon substrate, cover it with a patterned photolithography template, and maintain it at 45 °C in an oven for 50 min. As the solution evaporates, the polystyrene nanoparticles are assembled on the substrate to obtain a one-dimensional nanostructure. Place the chip with the one-dimensional nanostructure in an oven at 110 °C for 35 min to increase the adhesion force between the one-dimensional nanostructure and the substrate and prevent the one-dimensional nanostructure from being damaged during subsequent rinsing processes, thus preparing the nanophotonic chip.

[0069] Preparation of a detection chip for CEACAM1 protein: Prepare a solution of EDC (1-ethyl-(3-dimethylaminopropyl)carbodiimide) and a PBS solution of Sulfo-NHS (N-hydroxysulfosuccinimide) with concentrations of 10 mg / mL and 3 mg / mL, respectively. Mix the two solutions in a volume ratio of 1:1 to obtain a mixed solution. Immerse the above nanophotonic chip in the mixed solution and activate it at room temperature (20 °C) for 20 min to enhance the binding ability between the one-dimensional nanostructure and the antibody. Subsequently, drop the specific antibody against the cancer biomarker CEACAM1, Anti-CEACAM1 antibody, onto the activated nanophotonic chip for antibody incubation. The concentration of the incubated antibody is 10 μg / mL, and the incubation is carried out at 20 °C for 2 h. Subsequently, use a 10 mg / mL bovine serum albumin (BSA) solution to block the remaining active sites, and the blocking time is 10 min at room temperature (20 °C). After rinsing with deionized water, the CEACAM1 protein detection chip is obtained.

[0070] Take the selenium nanoparticle solution with a concentration of 0.01 mg / mL prepared in Preparation Example 1, mix the selenium nanoparticles with the target CEACAM1 protein, and incubate at room temperature (20 °C) for 20 min to obtain a selenium nanoprobe with the target CEACAM1 protein on its surface, denoted as the solution containing the selenium nanoprobe. Among them, the concentration of the target analyte is in the range of 1 pg / mL - 100 ng / mL. Drop the solution containing the selenium nanoprobe onto the CEACAM1 protein detection chip, place it on a shaker at 25 °C for capture. After 30 min, rinse the detection chip three times with deionized water and place it under an optical microscope for observation. Since the selenium nanoparticles in the probe are captured by the specific antibody on the chip along with the target CEACAM1 protein, a one-dimensional heteronanostructure is formed with the one-dimensional nanostructure on the detection chip. Under a normally incident light source, the reflection signal of the heteronanostructure is collected and imaged by a CCD camera through a 100-fold objective lens. Since there is a significant change in the reflection signal of the one-dimensional nanostructure before and after capturing the selenium nanoprobe, red abnormal points appear in the area where the selenium nanoprobe is bound. By observing the number and area of the abnormal points, visual detection can be achieved.

[0071] Example 3

[0072] Prepare a nanophotonic chip: Configure a colloidal solution of 500-nm polystyrene nanoparticles with a concentration of 3 mg / mL, add 1 mg / mL of SDS, take 10 μL of the colloidal solution and drop it on a silicon substrate. After covering the photolithography template, place it in an oven at 45 °C for printing for 50 min, and then put it in an oven at 110 °C for sintering for 35 min to obtain a one-dimensional polystyrene nanostructure, and prepare a nanophotonic chip.

[0073] Refer to Example 2 to prepare a CEACAM1 protein detection chip: After activation with EDC and NHS for 20 min, incubate the Anti-CEACAM1 antibody at 20 °C for 2 h, and then block the remaining active sites with a 10 mg / mL BSA solution to obtain a CEACAM1 protein detection chip.

[0074] Drop selenium nanoparticles into the CEACAM1 protein solution and mix for 20 min. Among them, the concentration of CEACAM1 protein is 10 ng / mL, and the concentration of selenium nanoparticles is 0.01 mg / mL to obtain a selenium nanoprobe with CEACAM1 protein on its surface. Mix the selenium nanoprobe and the test solution containing the target CEACAM1 protein and then drop it on the detection chip, and perform CEACAM1 protein detection in a shaker at 25 °C. The one-dimensional polystyrene nanostructure can capture the selenium nanoprobe with CEACAM1 protein on its surface through a specific antibody, and the capture process takes 30 min. After detection, rinse the chip with deionized water, place the chip under an optical microscope, and perform image analysis on the reflection signal of the one-dimensional nanostructure. It is found experimentally that after specifically capturing the selenium nanoprobe, the reflection signal of the one-dimensional nanostructure changes significantly and can be distinguished by the naked eye. Quantitatively analyze the color change of the optical signal before and after detection through Image J software, as Figure 3 shown.

[0075] Example 3A

[0076] Refer to Example 3 to prepare a detection chip for immunoglobulin, the difference is that: replace the Anti-CEACAM1 antibody with an immunoglobulin antibody (IgG antibody).

[0077] Selenium nanoparticles were added dropwise to the immunoglobulin solution and mixed for 20 min. Among them, the concentration of immunoglobulin was 10 ng / mL, and the concentration of selenium nanoparticles was 0.01 mg / mL; selenium nanoprobes with immunoglobulin on the surface were obtained. The selenium nanoprobes and the test solution containing the target immunoglobulin were mixed and then dropped onto the detection chip, and immunoglobulin detection was carried out in a shaker at 25 °C. The polystyrene one-dimensional nanostructure could capture the selenium nanoprobes with immunoglobulin on the surface through specific antibodies, and the capture process took 30 min.

[0078] Example 3B

[0079] Refer to Example 3 to prepare a detection chip for Tau protein, with the difference that: the Anti-CEACAM1 antibody was replaced with a Tau antibody (Tau antibody) of the microtubule-associated protein related to Alzheimer's disease (Tau protein).

[0080] Selenium nanoparticles were added dropwise to the Tau protein solution and mixed for 20 min. Among them, the concentration of Tau protein was 10 ng / mL, and the concentration of selenium nanoparticles was 0.01 mg / mL; selenium nanoprobes with Tau protein on the surface were obtained. The selenium nanoprobes and the test solution containing the target Tau protein were mixed and then dropped onto the detection chip, and Tau protein detection was carried out in a shaker at 25 °C. The polystyrene one-dimensional nanostructure could capture the selenium nanoprobes with Tau protein on the surface through specific antibodies, and the capture process took 30 min.

[0081] It can be seen from Examples 3, 3A and 3B that by changing the antibody incubated on the surface of the detection chip, the detection of other proteins can be achieved, such as CEACAM1 protein, immunoglobulin (IgG protein), microtubule-associated protein related to Alzheimer's disease (Tau protein), etc. As Figure 4 shown, the optical reflection signals of the one-dimensional nanostructure changed after detecting different proteins, and the change in color intensity was quantitatively analyzed by Image J software. Among them, control refers to dropping only the mixed solution of buffer solution and selenium nanoparticles on the detection chip of Example 3. Since the probe does not contain the target analyte and the signals of different detection chips are basically the same, only the detection chip of Example 3 was used as the blank control group (i.e., control).

[0082] Example 4

[0083] Prepare a detection chip for CEACAM1 protein according to the steps in Example 3. Subsequently, mix different concentrations of CEACAM1 protein and selenium nanoparticles and incubate them to obtain mixed solutions with different concentrations. Among them, the concentrations of CEACAM1 protein are 1 pg / mL, 10 pg / mL, 100 pg / mL, 1 ng / mL, 10 ng / mL, and 100 ng / mL respectively, and the concentration of selenium nanoparticles is 0.01 mg / mL. Drop the mixed solutions onto the above-mentioned detection chip respectively, and place it in a shaker at 25 °C for detection. After the detection is completed, wash the detection chip three times with deionized water. Place the detection chip under an optical microscope and perform image analysis on the detection chip. Realize the quantitative evaluation of the protein concentration in the solution according to the change in the optical signal intensity of the one-dimensional nanostructure. From Figure 5 It can be seen the adsorption situation of selenium nanoprobes corresponding to different concentrations of CEACAM1 protein. With the increase of the CEACAM1 protein concentration (i.e., the sample concentration), the number of selenium nanoprobes captured on the one-dimensional nanostructure also increases, and the optical signal intensities of the R, G, and B channels also change linearly accordingly, as Figure 5 corresponds to the green signal intensity after being processed by Image J. It can be seen that the detection system of the present application can detect the target protein in a wide concentration range of 1 pg / mL - 100 ng / mL, and the detection limit is as low as 1 pg / mL.

[0084] From the above test results, it can be known that the portable detection system of the present invention is not limited to the quantitative detection of CEACAM1 in cancer patients, but can also achieve the portable, visual, and sensitive detection of other related protein biomarkers, such as DNA, RNA, small molecules, etc.

[0085] The above has described the exemplary embodiments of the present invention. However, the protection scope of the present application is not limited to the above embodiments. Any modifications, equivalent replacements, improvements, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A detection system, characterized in that, The detection system includes a nanophotonic chip and a detection probe, wherein, the nanophotonic chip includes one-dimensional nanostructures and biomolecules; the biomolecules are modified on the one-dimensional nanostructures; the detection probe includes a target analyte and dielectric nanomaterials.

2. The detection system according to claim 1, characterized in that The nanophotonic chip can specifically recognize the target analyte corresponding to the biomolecule. Preferably, the target analyte is selected from at least one of proteins, nucleic acid molecules, etc. Preferably, the biomolecule or the target analyte can be independently fluorescently labeled or not.

3. The detection system according to claim 1 or 2, characterized in that, The dielectric nanomaterials are selected from one, two or more of silicon nanoparticles, selenium nanoparticles and titanium dioxide nanoparticles. Preferably, the dielectric nanomaterials are also surface-coated. Preferably, the surface-coating materials are polyvinylpyrrolidone, polyethylene glycol, carboxymethyl chitosan, polyacrylamide. Preferably, the diameter of the dielectric nanomaterials is 100 - 600 nm. Preferably, when the detection probe is used, it is also optionally incubated.

4. The detection system according to any one of claims 1 to 3, characterized in that, The target analyte and the dielectric nanomaterials are combined by chemical bonding or electrostatic adsorption. Preferably, after the detection probe is dropped onto the nanophotonic chip, the target analyte on the detection probe specifically binds to the biomolecule, and at the same time, the dielectric nanomaterials on the detection probe bind to the one-dimensional nanostructures.

5. The detection system according to any one of claims 1-4, characterized in that, The biomolecule and the one-dimensional nanostructure are connected by a chemical bonding method. Preferably, the one-dimensional nanostructure contains nanoparticles, one-dimensional nanowires, one-dimensional nanorods or one-dimensional nanocylinders. Preferably, the nanoparticles are spherical, cubic or rod-shaped nanoparticles. Preferably, the diameter of the nanoparticles is 100 - 800 nm.

6. The detection system according to any one of claims 1-5, characterized in that, The material of the one-dimensional nanostructure is selected from polymer nanomaterials. Preferably, the one-dimensional nanostructure can generate two scattering peaks in the visible light region.

7. The detection system according to any one of claims 1-6, characterized in that, The nanophotonic chip further includes a substrate, and the one-dimensional nanostructure is located on the surface of the substrate. Preferably, the substrate is selected from a silicon substrate, a glass substrate or a flexible polymer substrate.

8. The detection system according to any one of claims 1-7, characterized in that, The preparation method of the nanophotonic chip includes the following steps: soaking the substrate containing one-dimensional nanostructures in a mixed solution of NHS and EDC to activate the carboxyl group; then soaking the substrate in a solution containing biomolecules and incubating to obtain the nanophotonic chip.

9. The application of the detection system according to any one of claims 1 - 8 in the field of biological detection.

10. A method for using the detection system according to any one of claims 1-8, characterized in that, The specific steps are as follows: (1) Incubating the target analyte with dielectric nanomaterials to prepare a solution of the detection probe; (2) After dropping the solution of the detection probe onto the nanophotonic chip, the target analyte on the detection probe recognizes and specifically binds to the biomolecule on the one-dimensional nanostructure, and at the same time, the dielectric nanomaterials on the detection probe bind to the one-dimensional nanostructure; (3) Under the illumination of a normally incident light source, the changes in the optical signals of the nanophotonic chip before and after specific binding are respectively obtained.

Images