Optical fiber signal sensing immunodetection kit and detection method for cardiac troponin

Abstract

The invention belongs to the technical field of immunodetection, and discloses an optical fiber signal sensing immunodetection kit and detection method for cardiac troponin, the optical fiber signal sensing immunodetection kit comprises a capture probe and a signal probe; the capture probe comprises sensing optical fibers and cTnI antibodies I coupled to the sensing optical fibers, and 1.8 mu g to 3 mu g of the cTnI antibodies I are added into each sensing optical fiber; the signal probe comprises gold-platinum-iron oxide nano-metal particles coupled with a cTnI antibody II, and 35-45 [mu] g of the cTnI antibody II is added into every 1 mg of the gold-platinum-iron oxide nano-metal particles; the cTnI antibody I and the cTnI antibody II can be combined with different epitopes of cardiac troponin I. The optical fiber signal sensing immunodetection kit for the cardiac troponin can realize high-sensitivity detection of the cardiac troponin I.

Description

Technical Field

[0001] The present invention belongs to the technical field of immunoassay, and particularly relates to an optical fiber signal sensing immunoassay kit and a detection method for cardiac troponin. Background Art

[0002] At present, the detection of acute myocardial infarction (AMI) mainly relies on electrocardiogram (ECG), coronary angiography and specific biomarker detection. Although ECG is used for AMI diagnosis, due to its concealment and non-specificity in the early stage, more than 50% of patients with ST-segment elevation myocardial infarction (STEMI) are difficult to be diagnosed. Although coronary angiography can directly observe the morphology and blood flow of coronary arteries, its invasiveness and complexity limit rapid diagnosis, and it is costly and requires professional operation. Specific biomarker detections such as ELISA and CLIA show high sensitivity and accuracy in the quantitative measurement of myocardial injury markers, but the equipment is expensive, the operating environment requirements are strict, and the detection time is long. These limitations make it difficult to be widely applied in primary medical units with limited resources, especially in rural areas. Therefore, portable, simple and sensitive POCT detection equipment has become the key to solving this problem.

[0003] In response to this problem, portable and integrable POCT (Point-Of-Care Testing) devices have gradually gained attention. Among them, light initiated chemiluminescent assay (LICA) is a new type of chemiluminescent assay method that has been gradually accepted by clinical laboratories and applied to a certain extent. This technology is different from electrochemiluminescence, direct chemiluminescence, and enzyme-catalyzed chemiluminescence. It uses two kinds of labels, a luminescent material and a photoactive substance. The luminescent material is distributed on the surface of luminescent microspheres, and the photoactive substance is distributed on the surface of photosensitive microspheres, showing the characteristics of "double labels" and "double spheres". Through the binding between antigens and antibodies, the transfer of high-energy reactive oxygen species is realized between the two kinds of microspheres, inducing the process of photoexcited chemiluminescence, thus realizing "separation-free" homogeneous immunoassay, which has excellent performance such as simple operation, high analysis efficiency, and low instrument failure rate, and is deeply welcomed by clinical laboratories. Although it is simple and fast to operate, there are some significant drawbacks in the detection of cardiac troponin. First of all, the detection results of LICA are easily interfered. Due to relying on the immunoreaction on the nitrocellulose membrane, it is easily affected by other components in the sample or environmental factors, resulting in a decrease in the accuracy of the results. Secondly, the stability of LICA in quantitative detection is poor. Although the results can be obtained quickly, the repeatability and consistency of its quantitative detection are low, which is a major defect for clinical applications that require accurate measurement of the concentration of cardiac troponin. In addition, LICA can usually only perform qualitative or semi-quantitative detection, and it is difficult to provide accurate numerical results, and its detection equipment is large in size, which is not convenient to carry and use on-site.

[0004] The popularity and powerful functions of smartphones have brought new ideas to POCT technology. By combining smartphones and traditional detection technologies, a variety of POCT platforms have been developed. However, smartphones still face challenges such as camera differences and environmental interference in the detection of cardiac injury markers. The transmission light sensor (TLS) of smartphones has advantages such as a wide spectral response range, strong anti-interference ability, and low cost. By calculating the absorbance of metal antibodies based on the absorbance analysis principle, the direct detection of cardiac troponin can be realized. Although smartphone TLS has shown potential in biochemical detection, ultrasensitive detection still needs to be improved. Summary of the Invention

[0005] The purpose of the present invention is to provide an optical fiber signal sensing immunoassay kit capable of instantaneously and rapidly quantifying the concentration of cardiac troponin I.

[0006] The realization of the above purpose includes the following technical solutions.

[0007] The first aspect of the present invention provides an optical fiber signal sensing immunoassay kit for cardiac troponin, and the optical fiber signal sensing immunoassay kit includes a capture probe and a signal probe;

[0008] The capture probe includes a sensing optical fiber and cTnI antibody I coupled to the sensing optical fiber, and the amount of cTnI antibody I added to each sensing optical fiber is 1.8 μg to 3 μg;

[0009] The signal probe includes gold-platinum-iron oxide nanometal particles coupled with cTnI antibody II, and the amount of cTnI antibody II added to every 1 mg of gold-platinum-iron oxide nanometal particles is 35 μg to 45 μg;

[0010] The cTnI antibody I and the cTnI antibody II can bind to different epitopes of cardiac troponin I.

[0011] In some embodiments, the amount of cTnI antibody I added to each sensing optical fiber is 2 μg to 3 μg; preferably 2 μg to 2.5 μg; more preferably 2 μg to 2.2 μg.

[0012] In some embodiments, the amount of cTnI antibody II added to every 1 mg of gold-platinum-iron oxide nanometal particles is 38 μg to 45 μg, preferably 38 μg to 42 μg, more preferably 39 μg to 41 μg.

[0013] In some embodiments, the amount of the signal probe added to each 1 μL of the test sample is 0.1 μg to 0.15 μg, preferably 0.1 μg to 0.125 μg.

[0014] In some embodiments, the clone number of the cTnI antibody I is 16A11cc; and / or,

[0015] The clone number of the cTnI antibody II is 19C7cc.

[0016] In some embodiments, the preparation method of the signal probe includes the following steps:

[0017] Mix chloroauric acid, chloroplatinic acid and water and react to obtain a gold-platinum acid solution;

[0018] React the gold-platinum acid solution with ammonia water to obtain a gold-platinum ammine solution;

[0019] React the gold-platinum ammine solution with ferrous chloride solution to obtain a suspension of gold-platinum-iron oxide nanoparticles;

[0020] Mix the suspension of gold-platinum-iron oxide nanoparticles with 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide for an activation reaction to obtain an activated suspension of gold-platinum-iron oxide nanoparticles;

[0021] The obtained activated gold-platinum-iron oxide nanoparticle suspension was added with cTnI antibody II and incubated.

[0022] The incubated solution was added with a blocking solution for a blocking reaction to obtain a precipitate.

[0023] The obtained precipitate was added to a labeling complex solution and mixed evenly to obtain the signal probe.

[0024] Preferably, the concentration of ammonia water added is 0.4% w / v to 0.6% w / v, preferably 0.45% w / v to 0.55% w / v, and more preferably 0.48% w / v to 0.52% w / v. The concentration of the ferrous chloride solution added is 0.4 mol / L to 0.6 mol / L, preferably 0.45 mol / L to 0.55 mol / L, and more preferably 0.48 mol / L to 0.52 mol / L.

[0025] The dosage ratio of chloroauric acid, chloroplatinic acid, ammonia water and ferrous chloride is 0.006 mmol: 0.006 mmol: 450 μL to 550 μL: 2 mL to 7 mL; more preferably 0.006 mmol: 0.006 mmol: 480 μL to 520 μL: 2 mL to 4 mL.

[0026] In some embodiments, the labeling complex solution contains 4% w / v to 6% w / v BSA, 0.3% w / v to 0.7% w / v T-20, 4% w / v to 6% w / v sucrose, 18 mmol / L to 22 mmol / L Tris-HCl; and / or

[0027] The dosage ratio of the gold-platinum-iron oxide nanoparticles, 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide is 1 mg: 0.2 mg to 0.4 mg: 0.2 mg to 0.4 mg.

[0028] In some embodiments, the sensing optical fiber has a bare fiber section, and cTnI antibody I is coupled to the bare fiber section.

[0029] In some embodiments, the preparation method of the capture probe includes the following steps:

[0030] The middle section of the sensing optical fiber was stripped to obtain a bare fiber section, and the bare fiber section was mixed with piranha solution for hydroxylation treatment.

[0031] The hydroxylated bare fiber section was mixed with APTES solution for silanization treatment.

[0032] The silanized bare fiber section was mixed with glutaraldehyde solution for aldehyde group reaction.

[0033] The bare fiber segment after the aldehyde group reaction is mixed with cTnI antibody I and incubated.

[0034] The incubated bare fiber segment is immersed in a blocking solution for a blocking reaction, and after drying, the capture probe is obtained.

[0035] In some embodiments, the fiber optic signal sensing immunoassay kit further includes a fiber optic signal sensing immunoassay instrument; the fiber optic signal sensing immunoassay instrument includes a box body and a laser; the box body has an embedding groove for inserting a mobile terminal, the first end of the sensing optical fiber is connected to the laser, and the second end of the sensing optical fiber extends into the embedding groove and is used for transmitting the fiber optic signal into the light sensor of the mobile terminal.

[0036] In some embodiments, a first fiber optic connector is provided at the output end of the laser, the box body is provided with a second fiber optic connector communicating with the embedding groove, the first end of the sensing optical fiber is detachably connected to the first fiber optic connector, and the second end is detachably connected to the second fiber optic connector.

[0037] In some embodiments, a carrier is provided on one side of the box body facing away from the embedding groove, and a receiving groove for receiving a reaction container is formed on the carrier, and the opposite ends of the receiving groove along the extending direction of the box body have an opening structure.

[0038] In some embodiments, a groove is provided on the outer peripheral wall of the box body, and the sensing optical fiber is detachably received in the groove.

[0039] The second aspect of the present invention provides a method for detecting cardiac troponin for non-diagnostic purposes, including the following steps:

[0040] The sample to be tested is mixed and incubated with a signal probe, and the signal probe includes gold-platinum-iron oxide nanoparticles conjugated with cTnI antibody II.

[0041] The incubated sample is mixed and incubated with a capture probe, and the capture probe includes a sensing optical fiber and cTnI antibody I conjugated on the sensing optical fiber.

[0042] The light intensity value of the sensing optical fiber is measured by the light sensor of the mobile terminal.

[0043] In the present invention, cTnI antibody I is conjugated to a sensing optical fiber to obtain a capture probe, and cTnI antibody II is conjugated to gold-platinum-iron oxide nanoparticles to obtain a signal probe. Cardiac troponin I binds to cTnI antibody II on the signal probe and cTnI antibody I on the capture probe, forming a "gold-platinum-iron oxide nanoparticle-labeled cTnI antibody II - cardiac troponin I - cTnI antibody I" sandwich structure. A part of the 625 nm emission light of the sensing optical fiber is absorbed by the gold-platinum-iron oxide nanoparticles in the sandwich structure. Therefore, the concentration of cardiac troponin I in the test substance can be obtained by detecting the received light intensity signal, enabling highly sensitive detection of cardiac troponin I, capable of quickly and accurately detecting changes in the concentration of cardiac troponin I, with high repeatability and consistency for quantitative detection, significantly reducing the detection cost, and having broad application prospects in the diagnosis and treatment of heart diseases.

[0044] The present invention also finds that the dosage of the antibody in the capture probe, the dosage of the signal probe, and different signal probes have a great impact on the sensitivity, stability, and accuracy of the detection. By optimizing the dosage, there is an obvious gain effect in improving the detection sensitivity, stability, and accuracy. Description of the Drawings

[0045] Figure 1 is the overall structural schematic diagram of the fiber optic signal sensing immunoassay detector according to the embodiment of the present invention.

[0046] Figure 2 is Figure 1 a partial structural schematic diagram of the fiber optic signal sensing immunoassay detector from another angle.

[0047] Figure 3 is Figure 2 the exploded structural schematic diagram of the fiber optic signal sensing immunoassay detector.

[0048] Figure 4 is the detection result graph of the light intensity difference of standard product solutions with different concentrations.

[0049] Figure 5 is the detection result graph of the optical power of standard product solutions with different concentrations.

[0050] Figure 6 is the correlation result graph of the light intensity difference detection result and the optical power detection result.

[0051] Figure 7 is the SD value and CV value of the fiber optic signal sensing immunoassay detector for detecting standard products with different concentrations.

[0052] Figure 8 is the detection result graph of clinical samples using the fiber optic signal sensing immunoassay kit.

[0053] Figure 9 are different Fe x O y @Au α Pt β -NPs absorbance detection result graph.

[0054] Figure 10 is Fe x O y @Au α Pt β -NPs different addition amounts light intensity difference detection result graph.

[0055] Figure 11 is different optical fiber coating amounts light intensity difference detection result graph.

[0056] Figure 12 is different detection times light intensity difference detection result graph.

[0057] Explanation of the reference numerals:

[0058] 1. Box body; 11. Embedded groove; 12. Carrier; 121. Accommodating groove; 122. Bottom plate; 123. Side plate; 124. Top plate; 125. Notch; 13. Groove; 14. First fixing plate; 15. Second fixing plate; 2. Reaction vessel; 3. Laser; 4. Sensing optical fiber; 5. First optical fiber connector; 6. Second optical fiber connector; 7. Power supply. Detailed implementation manners

[0059] For ease of understanding of the present invention, the present invention will be described more comprehensively below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the understanding of the disclosed content of the present invention more thorough and comprehensive.

[0060] The experimental methods without specific conditions noted in the following embodiments are usually in accordance with conventional conditions or the conditions recommended by the manufacturer. All kinds of commonly used chemical reagents used in the embodiments are commercially available products.

[0061] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention are only for the purpose of describing specific embodiments and are not used to limit the present invention. The term "and / or" used in the present invention includes any and all combinations of one or more of the related listed items.

[0062] An embodiment of the present invention provides a fiber optic signal sensing immunoassay kit for cardiac troponin. The fiber optic signal sensing immunoassay kit includes a capture probe and a signal probe;

[0063] The capture probe includes a sensing optical fiber and cTnI antibody I coupled to the sensing optical fiber, and the amount of cTnI antibody I added to each sensing optical fiber is 1.8 μg to 3 μg;

[0064] The signal probe includes gold-platinum-iron oxide nano metal particles coupled with cTnI antibody II, and the amount of cTnI antibody II added to each 1 mg of gold-platinum-iron oxide nano metal particles is 35 μg to 45 μg;

[0065] The cTnI antibody I and the cTnI antibody II can bind to different epitopes of cardiac troponin I.

[0066] The optical fiber signal sensing immunoassay kit is based on the principle of immunosorption technology and includes the following:

[0067] Mix and incubate the serum sample with the signal probe (gold-platinum-iron oxide nano metal particles coupled with cTnI antibody II, Fe x O y @Au α Pt β -dAb). After the incubation ends, use a capillary or a microsyringe to aspirate about the sample and inject it into a glass reaction dish. Mix and incubate the sensing area of the sensing optical fiber coupled with cTnI antibody I with the sample in the glass reaction dish. Then immediately record the light intensity signal transmitted by the sensing optical fiber received by the ambient light sensor of the smartphone as the initial value, denoted as Δ1. If cardiac troponin I is contained in the serum, it will bind to the Fe x O y @Au α Pt β -dAb signal probe and cTnI antibody I on the optical fiber to form a "double antibody sandwich structure of gold-platinum-iron oxide nanoparticles labeled cTnI antibody II - cardiac troponin I - cTnI antibody I". At this time, a part of the 625 nm emission light passing through the sensing area of the sensing optical fiber will be absorbed by the gold-platinum-iron oxide nanoparticles; after incubating for a period of time, use a capillary glass tube or a microsyringe to remove the serum, and then record the light intensity signal received by the ambient light sensor of the smartphone as the final value, denoted as Δ2. Perform a difference analysis according to the ambient light sensor application program of the smartphone, and select the difference between the final value and the initial value (Δ2 - Δ1) as the analysis value. Δ2 - Δ1 is the light intensity value absorbed by the gold-platinum-iron oxide nanoparticles, and the concentration of cardiac troponin I in the test substance is immediately defined by calculating the light intensity value absorbed by the gold-platinum-iron oxide nanoparticles.

[0068] It can be seen from this that according to the above method of coupling cTnI antibody I to the sensing optical fiber to obtain a capture probe, and coupling cTnI antibody II to the gold-platinum-iron oxide nanoparticles to obtain a signal probe. Through the binding of cardiac troponin I to cTnI antibody II on the signal probe and cTnI antibody I on the capture probe, a sandwich structure of "gold-platinum-iron oxide nanoparticles-labeled cTnI antibody II - cardiac troponin I - cTnI antibody I" is formed. A part of the 625 nm emission light of the sensing optical fiber is absorbed by the gold-platinum-iron oxide nanoparticles in the sandwich structure. Therefore, the concentration of cardiac troponin I in the test substance can be obtained by detecting the received light intensity signal, enabling highly sensitive detection of cardiac troponin I, quickly and accurately detecting the concentration change of cardiac troponin I, with high repeatability and consistency for quantitative detection, significantly reducing the detection cost, and having broad application prospects in the diagnosis and treatment of heart diseases.

[0069] In some embodiments, the amount of cTnI antibody I added to each sensing optical fiber is 2 μg to 3 μg; preferably 2 μg to 2.5 μg; more preferably 2 μg to 2.2 μg.

[0070] In some embodiments, the amount of cTnI antibody II added to every 1 mg of gold-platinum-iron oxide nanoparticles is 38 μg to 45 μg, preferably 38 μg to 42 μg, more preferably 39 μg to 41 μg.

[0071] In some embodiments, the amount of the signal probe added to every 1 μL of the test sample is 0.1 μg to 0.15 μg, preferably 0.1 μg to 0.125 μg.

[0072] In some embodiments, the sensing optical fiber 4 has a bare fiber section, and cTnI antibody I is coupled to the bare fiber section.

[0073] In some embodiments, the clone number of cTnI antibody I is 16A11cc.

[0074] In some embodiments, the clone number of cTnI antibody II is 19C7cc.

[0075] In some embodiments, as Figures 1 - 3As shown, the optical fiber signal sensing immunoassay kit also includes an optical fiber signal sensing immunoassay instrument; the optical fiber signal sensing immunoassay instrument includes a box body 1 and a laser 3; the box body 1 has an embedding groove 11 for inserting a mobile terminal, the first end of the sensing optical fiber 4 is connected to the laser 3, and the second end of the sensing optical fiber 4 extends into the embedding groove 11 and is used to transmit the optical fiber signal to the optical sensor of the mobile terminal. Wherein, the reaction container 2 such as a capillary is injected with a test sample such as serum, wherein the test sample has been incubated with a signal probe (oxidized gold platinum iron nanometal particles coupled with antibody 2) in advance, and the bare fiber section of the sensing optical fiber 4 coupled with the detection antibody 1 is embedded in the capillary, so that a double antibody sandwich structure of antibody 1-test protein and antibody 2 can be formed in the capillary, and a mobile terminal such as a smart phone is inserted into the embedding groove 11, and then the laser 3 switch is turned on, and the current is adjusted to 2A, and the test sample can be qualitatively and quantitatively detected by performing differential analysis according to the ambient light sensor application of the smart phone.

[0076] Specifically, the reaction container 2 is a capillary, and the bare fiber segment is embedded in the capillary for reaction. Specifically, by setting the reaction container 2 as a capillary, the test sample can be sucked through other capillaries or micro-syringes, and the interfaces of the two can be docked to conveniently inject the test sample into the reaction container 2, and it can effectively prevent the test sample from flowing out of the reaction container 2 under natural conditions. The bare fiber segment of the sensing optical fiber 4 is stripped of a 2-2.5 cm bare fiber segment in the middle section of the optical fiber by using an optical fiber stripping pliers, and then the optical fiber is fixed on a manual taper platform, and a flamethrower is used to burn the bare fiber segment, and the optical fiber is tapered to obtain a bare fiber segment, that is, the core diameter of the bare fiber segment is smaller than the core diameter of other areas, so that it can be embedded in the inner cavity of the capillary for reaction.

[0077] In some embodiments, Figure 2 As shown, a carrier 12 is provided on the side of the box body 1 away from the embedding groove 11, and a receiving groove 121 is provided on the carrier 12, and the receiving groove 121 has an opening structure at two opposite ends along the extension direction of the box body 1. Specifically, the carrier 12 is arranged along the length direction of the back of the box body 1, and the carrier 12 has the opening structure at two opposite ends along the length direction of the box body 1, wherein the openings at two opposite ends of the carrier 12 facilitate the insertion of the capillary from the openings and facilitate the removal of the capillary when replacing it, and facilitate the docking of the interface of the capillary with other capillaries or micro-syringes after absorbing the test sample to inject the test sample into the reaction container 2.

[0078] Specifically in the embodiment, Figure 2As shown, the carrier 12 includes a bottom plate 122, a side plate 123, and a top plate 124. The first end of the bottom plate 122 is connected to the box body 1, the second end of the bottom plate 122 is connected to the bottom end of the side plate 123, the top end of the side plate 123 is connected to the top plate 124, and a gap is formed between one end of the top plate 124 away from the side plate 123 and the box body 1. The bottom plate 122, the side plate 123, and the top plate 124 cooperate to form the receiving groove 121 with openings at both ends and the top.

[0079] In some embodiments, a notch 125 is formed in the middle of the carrier 12, so that the carrier 12 forms a segmented layout structure on the box body 1. Among them, by forming the notch 125 in the middle of the carrier 12, the middle part of the capillary is exposed outside the carrier 12. The operator can quickly replace the capillary by applying an external force to the capillary exposed outside the carrier 12 to make it extend out from the end opening.

[0080] In some embodiments, as Figure 1 shown, the sensing optical fiber 4 is wound around the outer peripheral wall of the box body 1. Specifically, the laser 3 is arranged inside the box body 1. Among them, the embedding groove 11 is arranged at the front end of the box body 1 facing the operator, the carrier 12 is arranged at the back end of the box body 1, the laser 3 is horizontally arranged inside the box body 1, and the output end of the laser 3 is arranged on the left side of the box body 1. Therefore, since the sensing optical fiber 4 needs to extend from the position of the laser 3 to the reaction vessel 2 at the carrier 12 and then terminate at the mobile terminal at the embedding groove 11, it has a relatively long length. By winding the sensing optical fiber 4 around the outer peripheral wall of the box body 1, the laser 3, the reaction vessel 2, and the mobile terminal can be well associated together, which is convenient for assembly and makes the wiring more regular, avoiding messy lines.

[0081] Specifically in the embodiment, as Figure 1 shown, a groove 13 is provided on the outer peripheral wall of the box body 1, and the sensing optical fiber 4 is detachably received in the groove 13. The sensing optical fiber 4 is clamped in the groove 13, which can fix the sensing optical fiber 4 better on the box body 1, further improve the stability of the sensing optical fiber 4, and has the characteristics of being convenient for disassembly and assembly.

[0082] In some embodiments, as Figure 1As shown, a first optical fiber connector 5 is provided at the output end of the laser 3. The box body 1 is provided with a second optical fiber connector 6 communicating with the embedded groove 11. The first end of the sensing optical fiber 4 is detachably connected to the first optical fiber connector 5, and the second end is detachably connected to the second optical fiber connector 6. Among them, the first optical fiber connector 5 and the second optical fiber connector 6 are conventional optical fiber connectors, which can stably and detachably connect the sensing optical fiber 4 to the preset positions of the laser 3 and the box body 1. By fixedly arranging the first optical fiber connector 5 at the output end of the laser 3 and the second optical fiber connector 6 at the embedded groove 11, the sensing optical fiber 4 can be assembled quickly, accurately and detachably.

[0083] In some embodiments, as Figure 1 shown, the box body 1 extends outward with a first fixing plate 14 and a second fixing plate 15 corresponding to the position of the embedded groove 11. The first fixing plate 14 and the second fixing plate 15 are arranged oppositely, and clamping grooves are formed on the opposite sides of the first fixing plate 14 and the second fixing plate 15. The mobile terminal is inserted into the embedded groove 11 along the clamping grooves. Among them, the first fixing plate 14 and the second fixing plate 15 limit the opposite sides of the mobile terminal such as a smart phone, and the embedded groove 11 limits the head end of the smart phone, so that the smart phone can be accurately inserted into the embedded groove 11, and the optical sensor of the smart phone can be accurately aligned with the second end of the sensing optical fiber 4, so that the optical signal of the sensing optical fiber 4 can be accurately conducted to the optical sensor of the smart phone for result detection.

[0084] In some embodiments, the laser 3 can emit a laser of 625 nm.

[0085] In some embodiments, as Figure 3 shown, a power supply 7 is further provided in the box body 1. The power supply 7 is used to supply power to the laser 3 and has a charging and power storage function.

[0086] In some embodiments, a power control device for controlling the power of the laser 3 is further provided on the box body 1. The control knob of the power controller is aligned with and engaged with the knob opening of the box body 1 for power control of the laser 3.

[0087] In some embodiments, conventional components such as a microcontroller and a switch are further provided on the box body 1. Among them, the microcontroller is placed at the bottom inside the box body 1, and the switch is arranged on the surface of the box body 1. The microcontroller is connected to the laser 3, the power controller and the switch for controlling the working states of each component.

[0088] The following describes the solution of the present invention in combination with specific embodiments.

[0089] Embodiment 1 Construction of a method for detecting cardiac troponin I

[0090] The fiber optic signal sensing immunoassay kit is based on the principle of immunosorption technology and includes the following:

[0091] Assemble the sensing optical fiber and the fiber optic signal sensing immunoassay detector, and insert the smartphone into the embedding groove of the box body. Mix and incubate the serum sample with the signal probe (gold-platinum-iron oxide nanoparticles conjugated with cTnI antibody II, Fe x O y @Au α Pt β -dAb). After the incubation ends, use a capillary or a microsyringe to aspirate about the sample and inject it into a glass reaction dish. Mix and incubate the sensing area of the sensing optical fiber conjugated with cTnI antibody I (16A11cc antibody) with the sample in the glass reaction dish. Then turn on the switch, adjust the current of the power controller to 2 A, and immediately record the light intensity signal received by the ambient light sensor of the smartphone as the initial value, denoted as Δ1. If myocardial troponin I is contained in the serum, it will bind to the Fe x O y @Au α Pt β -dAb signal probe and the 16A11cc capture probe on the optical fiber to form a "double antibody sandwich structure of gold-platinum-iron oxide nanoparticle-labeled cTnI antibody II - myocardial troponin I - cTnI antibody I". At this time, a part of the 625 nm emitted light passing through the sensing area of the sensing optical fiber will be absorbed by the gold-platinum-iron oxide nanoparticles; after incubating for a period of time, use a capillary glass tube or a microsyringe to remove the serum, and then record the light intensity signal received by the ambient light sensor of the smartphone as the final value, denoted as Δ2. Perform a difference analysis according to the ambient light sensor application program of the smartphone, and select the difference between the final value and the initial value (Δ2 - Δ1) as the analysis value. Δ2 - Δ1 is the light intensity value absorbed by the gold-platinum-iron oxide nanoparticles, and the concentration of myocardial troponin I in the test substance is immediately defined by calculating the light intensity value absorbed by the gold-platinum-iron oxide nanoparticles.

[0092] 1.1 The experimental reagents are as follows in the table

[0093] Table 1 Experimental reagents

[0094]

[0095]

[0096] 1.2 Preparation of main solutions

[0097] (1) Prepare phosphate buffer solution (PBS, 1×) with a concentration of 0.015 mol / L and pH = 7.0, 0.1 mol / L MES buffer solution with pH = 7.0, 10 mg / mL EDC solution (prepared and used immediately), 10 mg / mL NHS solution (prepared and used immediately), and 10% (w / v) BSA solution according to conventional methods.

[0098] (2) Prepare the labeling complex solution as shown in Table 2

[0099] Table 2 Formulation of the Labeling Complex Solution

[0100] Reagent Name Concentration Quantity Unit BSA 5％ 2.5 g Tween - 20 0.5％ 250 μL Sucrose 5％ 2.5 g Tris - HCl 20 mmol / L 20 -

[0101] For the above-prepared solutions, the group activator EDC solution and NHS solution need to be prepared and used immediately and cannot be stored for a long time; except for 1×PBS, the rest are stored in a refrigerator at 4°C.

[0102] 1.3 Preparation of Gold-Platinum-Iron Oxide Nanoparticle Suspension

[0103] (1) Prepare a solution of HAuCl with a concentration of 24 mmol / L 4 and a solution of H 2 PtCl 6 , and mix them in a 1:1 ratio to form a 0.5 ml mixture;

[0104] (2) Add the mixture to 200 ml of water and continuously stir to obtain a chloroauric acid solution. Rapidly add 500 μL of 0.5% ammonia water to the mixture under the conditions of 300 rpm and 25°C, and continuously stir for 2 min to obtain a chloroauric acid ammine solution;

[0105] (3) Prepare 3 mL of a 0.5 mol / L solution of FeCl 2 , and quickly add it to the chloroauric acid ammine solution, and continuously stir for 20 min;

[0106] (4) Centrifuge at 8000 rpm for 10 min;

[0107] (5) Wash the obtained product 3 times with 50 mL of H 2 O;

[0108] (6) Resuspend the obtained product in 6 mL of H 2 O to obtain a gold-platinum-iron oxide nanoparticle suspension, named Fe x O y @Au α Pt β -NPs (2 mg / mL).

[0109] 1.4 Preparation of Signal Probe

[0110] After the above-mentioned preparation of the gold-platinum-iron oxide nanoparticle suspension, before preparing the signal probe by the microsphere immunolabeling antibody technique with cTnI antibody II, the surface of the gold-platinum-iron oxide nanoparticles needs to be treated, and an amide reaction occurs with the amino group on the antibody under the activation of EDC / NHS to form a stable amide bond. The specific steps are as follows:

[0111] (1) Ultrasonically resuspend and mix the Fe x O y @Au α Pt β -NPs suspension (power 5%, on for 2 s, off for 3 s), repeat 12 times until the precipitate is uniformly dispersed into a solution, and then pipette 0.5 mL of the Fe x O y @Au α Pt β -NPs suspension, and dilute it to 1 mL of a Fe x O y @Au α Pt β -NPs suspension with a concentration of 1 mg / mL;

[0112] (2) Mix 1 mL of the Fe x O y @Au α Pt β -NPs suspension with a concentration of 1 mg / mL with 100 μL of sodium polyacrylate (PAA), and incubate at room temperature with rotation for 2 h;

[0113] (3) Use 1 mL of pure water to centrifuge the PAA-incubated Fe x O y @Au α Pt β -NPs at 8000 rpm for 5 min, purify, and disperse in 2 mL of MES buffer (10 mmol / L, pH = 7.0);

[0114] (4) Add 20 μL of the EDC activation solution (concentration 10 mg / mL) and 20 μL of the NHS solution (concentration 10 mg / mL) to the above solution, vortex and mix well, and activate at room temperature by rotating and mixing on a rotary mixer for 40 min to obtain the activated gold-platinum-iron oxide nanoparticle suspension;

[0115] (5) Add 9.76 μL (4.1 mg / mL) of cTnI antibody II (19C7cc antibody) to the activated gold-platinum-iron oxide nanoparticle suspension, wrap it with tin foil to avoid light at room temperature, and incubate with rotation on a rotary mixer for 3 h;

[0116] (6) Add 20 μL of BSA (1%) blocking solution to the above solution. Under room temperature conditions, wrap it with tin foil to avoid light and rotate and mix it on a disk rotary mixer for 30 min;

[0117] (7) Use 1 mL of pure water to centrifuge Fe x O y @Au α Pt β -dAb at 8000 rpm for 5 min, and repeat the purification 3 times;

[0118] (8) Discard the supernatant, add 1 mL of labeling complex solution (5% w / v BSA, 0.5% w / v T-20, 5% w / v sucrose, 20 mmol / L Tris-HCl) to the precipitate, and ultrasonically mix the precipitate thoroughly to successfully prepare a signal probe (Fe x O y @Au α Pt β -dAb) conjugated with gold-platinum-iron nanoparticles of cTnI antibody II, and store it in a refrigerator at 4 °C in the dark for later use.

[0119] 1.5 Preparation of capture probe

[0120] (1) Prepare a Corning multimode optical fiber of appropriate length, and perform pretreatment on the optical fiber. Use an optical fiber stripping pliers to strip a 2 - 2.5 cm bare fiber segment in the middle of the optical fiber, and strip the coating layers at both ends of the optical fiber. The stripped ends of the optical fiber are used for subsequent assembly with the first connector (optical fiber probe) and the second connector (optical fiber probe) of the optical fiber signal sensing immunoassay detector. Then fix the optical fiber on a manual fiber taper platform, and use a flame torch to burn the bare fiber segment to perform a fiber tapering operation on the optical fiber to obtain a bare fiber segment with a tapering length of about 1 cm and a total length of the bare fiber segment of about 3 - 3.5 cm.

[0121] (2) Bend the prepared optical fiber by about 90°, and fix it on the surface of a glass slide with medical tape, with the bare fiber segment protruding. Fix the glass slide at an appropriate height on an iron stand;

[0122] (3) Mix 98% concentrated sulfuric acid and 30% H 2 O 2 in a ratio of 3:1 to prepare piranha solution. Then place the piranha solution on the iron stand and immerse the bare fiber segment in the piranha solution for 30 min to hydroxylate the bare fiber segment (hereinafter referred to as the sensing area);

[0123] (4) Soak the sensing area in pure water for 5 min to remove the residual solution;

[0124] (5) Mix absolute ethanol with 3-aminopropyltriethoxysilane (APTES) to prepare a 5% APTES solution. Subsequently, place the 5% APTES solution on an iron stand, and immerse the sensing area in the 5% APTES solution for 2 h to generate amino groups.

[0125] (6) Immerse the sensing area in pure water for 5 min to remove the residual solution.

[0126] (7) Mix PBS with glutaraldehyde to prepare a 5% glutaraldehyde solution. Subsequently, place the 5% APTES solution on an iron stand, and immerse the sensing area in the 5% APTES solution for 30 min. One aldehyde group of glutaraldehyde reacts with the amino group of the fiber, and the other aldehyde group of glutaraldehyde can bind to the amino group of cTnI antibody I in the next step.

[0127] (8) Wash the sensing area 3 times with pure water.

[0128] (9) Mix PBS with cTnI antibody I (16A11cc antibody) to prepare an antibody solution, about 2 μg of antibody per optical fiber. Place the antibody solution on an iron stand, and immerse the sensing area in the antibody solution for 4 h to successfully immobilize the cTnI-16A11cc antibody on the surface of the sensing area.

[0129] (10) Wash the unreacted antibody with pure water.

[0130] (11) Immerse the optical fiber in a 1% BSA blocking solution for 30 min to block the unreacted aldehyde groups on the fiber surface and obtain a capture probe (a sensing optical fiber conjugated with 16A11cc antibody).

[0131] 1.6 Structure of the optical fiber signal sensing immuno-detector

[0132] As Figures 1 to 3 shown, the optical fiber signal sensing immuno-detector includes a box body, a microcontroller, a 625 nm laser, a power controller, a switch, a rechargeable battery, a capillary, a first optical fiber connector, and a second optical fiber connector. The capillary serves as a reaction container and is fitted with the sensing optical fiber. The sensing optical fiber is used for the detection and sensing of cardiac troponin I. The microcontroller is used for the conversion of power supply and the laser. The 625 nm laser is used for the emission of optical signals. The power controller is used for the power control of the rechargeable battery. The rechargeable battery is used for the power supply of the detection device. The switch controls the state of the detector. The 625 nm laser is arranged in the box body. The smart phone is inserted into the embedding groove of the box body. The capillary is carried on the carrier. The first end of the sensing optical fiber is connected to the laser through the first optical fiber connector. The second end of the sensing optical fiber extends into the embedding groove through the second optical fiber connector and is used for transmitting the optical fiber signal to the optical sensor of the mobile terminal. The bare fiber segment part of the sensing optical fiber embedded in the capillary is conjugated with cTnI antibody I (16A11cc antibody).

[0133] The detection steps of this fiber optic signal sensing immunoassay instrument are as follows:

[0134] (1) Take 100 μL of the sample to be tested and add it to a capillary glass reaction dish. Turn on the switch of the fiber optic signal sensing immunoassay instrument and control the current to 2 A, and record the initial value Δ1 measured by the ambient light sensor of the smartphone.

[0135] (2) After 5 minutes, remove the sample and record the final value Δ2 measured by the ambient light sensor of the smartphone.

[0136] (3) Use the difference between the final value and the initial value (Δ2 - Δ1) as the analysis value.

[0137] 1.7 Preparation of serum

[0138] (1) Freshly collected venous blood (2 - 5 mL) is placed in a red-capped blood collection tube (without added anticoagulant), left to stand at room temperature for 30 - 60 minutes or at 2 - 8 °C overnight until the blood coagulates.

[0139] (2) Centrifugation: At room temperature, 3500 rpm, for 5 minutes.

[0140] (3) Sampling: Extract the upper layer of serum for testing.

[0141] (4) Preservation: Store at 2 - 8 °C for 24 hours and at -15 °C or below for 90 days.

[0142] Example 2 Detection of cardiac troponin I

[0143] (1) Standard sample detection

[0144] Use the three sensing optical fibers prepared in Example 1 and the fiber optic signal sensing immunoassay instrument to detect standard sample solutions with different concentrations (0.1 ng / mL, 0.2 ng / mL, 0.4 ng / mL, 0.8 ng / mL, 1.6 ng / mL, Shanghai Lingchao Biotechnology, recombinant cardiac troponin I (cTnI) antigen), and detect 3 times with a smartphone and a optical power meter respectively.

[0145] The detection method is as follows:

[0146] Smartphone detection operation: Fit the smartphone into the embedding slot of the fiber optic signal sensing immunoassay instrument, and mix 100 μL of serum sample with 10 μL of Fe x O y @Au α Pt β-dAb hybrid incubation. After the incubation, use a capillary or a microsyringe to aspirate 50 μL of the sample and inject it into a glass reaction dish. Then turn on the switch, adjust the current of the power controller to 2 A, and immediately record the light intensity signal received by the ambient light sensor of the smartphone as the initial value, denoted as Δ1. After incubating for 6 min, use a capillary glass tube or a microsyringe to remove the serum, and then record the light intensity signal received by the ambient light sensor of the smartphone as the final value, denoted as Δ2. Perform a difference analysis according to the ambient light sensor application program of the smartphone, and select the difference between the final value and the initial value (Δ2 - Δ1) as the analysis value. The results are as Figure 4 shown.

[0147] Optical power meter detection operation: Fit the optical power meter into the embedded slot of the fiber optic signal sensing immunoassay detector. Mix the serum sample with Fe x O y @Au α Pt β -dAb hybrid incubation. After the incubation, use a capillary or a microsyringe to aspirate about the sample and inject it into a glass reaction dish. Then turn on the switch, adjust the current of the power controller to 2 A, and immediately record the light intensity signal received by the optical power meter as the initial value, denoted as α1. After incubating for 6 min, use a capillary glass tube or a microsyringe to remove the serum, and then record the light intensity signal received by the optical power meter as the final value, denoted as α2. Perform a difference analysis according to the results of the optical power, and select the difference between the final value and the initial value (α2 - α1) as the analysis value. The results are as Figure 5 shown.

[0148] Analysis of detection results:

[0149] As Figure 6 shown, by comparing the numerical values of the two signal detection devices, detect standard solutions with different concentrations using an optical power meter and a smartphone respectively. Take the numerical values of the optical power meter as the X-axis and the numerical values of the smartphone as the Y-axis to plot the detection curve and the detected standard curve after fitting. The detection results of the two signal receiving devices have a high degree of correlation, and the linear range of the device detection is 0.1 - 1.6 ng / mL.

[0150] (2) Stability analysis

[0151] Use the sensing optical fiber prepared in Example 1 and the fiber optic signal sensing immunoassay detector to detect the concentrations of standard products (Shanghai Lingchao Biotechnology, recombinant cardiac troponin I (cTnI) antigen) with high, medium, and low concentrations (1.6 ng / mL, 0.8 ng / mL, 0.2 ng / mL) respectively, and repeat each concentration five times. The detection method is as follows:

[0152] At the same time, as shown in Table 3 below and Figure 7As shown, both the SD value and CV value of the sensing optical fiber detection standard product are within the acceptable range, and the CV value of this detection method can be controlled within 15%, meeting the requirements of clinical detection.

[0153] Table 3 Stability Analysis

[0154] Group Mean Standard Deviation (SD) Coefficient of Variation (CV) High Value Group (1.6 ng / mL) 1.564 ng / mL 0.157 10.02％ Medium Value Group (0.8 ng / mL) 0.709 ng / mL 0.050 7.00％ Low Value Group (0.2 ng / mL) 0.214 ng / mL 0.021 9.68％

[0155] (3) Recovery Analysis

[0156] The sensing optical fiber prepared in Example 1 was combined with an optical fiber signal sensing immunoassay detector to detect standard products at three concentrations (high, medium, and low) respectively. The concentrations of the standard products (Shanghai Lingchao Biotechnology, recombinant cardiac troponin I (cTnI-16A11cc) antigen) were (1.6 ng / mL, 0.8 ng / mL, 0.2 ng / mL), and each concentration was repeated five times.

[0157] At the same time, as shown in Table 4 below, the recovery rate of the sensing optical fiber for detecting standard products was controlled within 85-115%, meeting the requirements of clinical detection.

[0158] Table 4 Recovery Analysis

[0159]

[0160]

[0161] (4) Clinical Sample Detection

[0162] Twenty-one clinical samples (from the Second People's Hospital of Guangdong Province) were taken, and the sensing optical fiber prepared in Example 1 was combined with an optical fiber signal sensing immunoassay detector to detect them respectively. The ambient light sensor of a smartphone was used as the receiving device, and the detection results are as follows Figure 8 As shown, the lowest detection limit of the present invention is 0.036 ng / mL, and the detection range is 0.08-1.5 ng / mL, which has met the clinical detection requirements.

[0163] In summary, an optical fiber signal sensing immunoassay detector was constructed by using a 625 nm laser signal emitter and assembled components. Its power can be freely controlled. By combining the sensing optical fiber with the optical fiber signal sensing immunoassay detector, a fiber optic signal sensing immunoassay kit for cardiac troponin can be obtained. The sandwich immunoassay method can be used to initiate the subsequent analysis process, and the ambient light sensor of a smartphone can be used to determine the change of the optical signal; a sensing immunoassay device based on optical signals is formed, which can achieve one-step sample addition and one-step reaction, is less affected by the environment, has an economical cost, and is easy to operate. It can be effectively applied to immunoassay with a wide range of application scenarios.

[0164] Example 3

[0165] According to the method of Example 1, different Fe x O y @Au α Pt β -NPs, determination of Fe by absorbance x O y @Au α Pt β -The light absorption properties of NPs.

[0166] Different concentrations of NH 3 ·H 2 O and FeCl 2 Solution, NH 3 ·H 2 O and FeCl 2 The concentrations of the solutions added were 0.5% w / v NH 3 ·H 2 O+0.1mol / L FeCl 2 , 0.03% w / v NH 3 ·H 2 O+0.5mol / LFeCl 2 , 0.03% w / v NH 3 ·H 2 O+0.1mol / L FeCl 2 , 0.5% w / v NH 3 ·H 2 O+0.5mol / LFeCl 2 , 0.5% w / v NH 3 ·H 2 O+0.3mol / LFeCl 2 After the preparation is completed, the suspension is fully ultrasonicated and Fe x O y @Au α Pt β -NPs were subjected to absorbance detection.

[0167] Analysis results: Figure 9 As shown, in the preparation of Fe x O y @Au α Pt β -NPs were added at a concentration of 0.5% NH 3 ·H 2 O and a concentration of 0.5 mol FeCl 2 When the prepared Fe x O y @Au α Pt β-NPs have the highest absorbance and can more effectively absorb the 625 nm emission light, resulting in a more obvious attenuation of the light intensity. This significant change in light intensity makes the detection signal easier to detect and analyze, helps improve the detection sensitivity of the detection device for cTnI, and thus enables rapid and accurate diagnosis of acute myocardial infarction.

[0168] Example 4

[0169] Prepare Fe x O y @Au α Pt β -dAb according to the method of Example 1, and determine the coupling efficiency of the signal probe by the magnitude of the light intensity difference (Δ2 - Δ1). Add different amounts of Fe x O y @Au α Pt β -dAb to 100 μL of plasma samples, which are 5 μL, 7.5 μL, 10 μL, 12.5 μL, and 15 μL respectively. After sufficient reaction, use the fiber optic signal sensing immunoassay kit to test respectively, where the sample volume for each test is 30 μL and the concentration of cTnI is about 0.8 ng / mL.

[0170] Analysis results: As Figure 10 shown, when detecting the concentration of cardiac troponin, the optimal addition amount of Fe x O y @Au α Pt β -dAb is 10 μL / test. At this time, the light intensity difference is the largest, the coupling efficiency is the highest, which can significantly improve the detection sensitivity, make it easier for the instrument to capture the signal, facilitate the discovery of low-content cTnI, enhance the detection accuracy, reduce interference signals, lower the probability of misjudgment, and also improve the detection stability, ensure the result repeatability, and facilitate data processing.

[0171] Example 5

[0172] Prepare the sensing optical fiber according to the method of Example 1, and determine the coupling efficiency of the signal probe by the magnitude of the light intensity difference (Δ2 - Δ1).

[0173] Add different masses of cTnI-16A11cc antibody during the preparation of the sensing optical fiber, which are 0.5 μg, 1 μg, 1.5 μg, 2 μg, and 2.5 μg respectively. Then add 10 μL of Fe x O y @Au α Pt β-dAb. After sufficient reaction, the fiber optic signal sensing immunoassay kit was used for testing respectively, with the sample volume of each test being 30 μL and the concentration of cTnI being approximately 0.4 ng / mL.

[0174] Analysis results: As Figure 11 shown, when preparing the sensing optical fiber, the optimal addition amount of cTnI-16A11cc antibody is 2 μg / root, at which time the light intensity difference is the largest and the coupling efficiency is the highest.

[0175] Example 6

[0176] Serum was prepared according to the method of Example 1. Subsequently, cardiac troponin I was added to the negative serum, and the serum was divided into a high concentration group (1.5 ng / mL), a medium concentration group (1.0 ng / mL), and a low concentration group (0.2 ng / mL) according to the concentration of cardiac troponin I; 100 μL of sample volume was prepared for each group, and 10 μL of FexOy@AuαPtβ-dAb signal probe was added to each group and incubated for 15 min. The sensing optical fiber and the fiber optic signal sensing immunoassay kit were assembled, and the smart phone was embedded with the fiber optic signal sensing immunoassay kit. After the incubation, about 30 μL of serum was respectively aspirated using a capillary or a micro syringe and injected into a glass reaction dish. Then the switch was turned on, the current of the power controller was adjusted to 2 A, and the light intensity signal received by the ambient light sensor of the smart phone was immediately recorded as the initial value, denoted as Δ1. Subsequently, the reaction was carried out for 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 10 min, and 15 min respectively. Then the serum was removed using a capillary glass tube or a micro syringe, and the light intensity signal received by the ambient light sensor of the smart phone was recorded again as the final value, denoted as Δ2. According to the difference analysis of the ambient light sensor application program of the smart phone, the difference between the final value and the initial value (Δ2 - Δ1) was selected as the analysis value, and the highest value of Δ2 - Δ1 was taken as the optimal detection time of cardiac troponin I. As Figure 12 shown, when the detection time is 6 min, it is the optimal detection time.

[0177] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0178] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A fiber optic signal sensing immunoassay kit for cardiac troponin, characterized in that: The optical fiber signal sensing immunoassay kit comprises a capture probe and a signal probe; The capture probe includes a sensing optical fiber and a cTnI antibody coupled to the sensing optical fiber, and the cTnI antibody added to each sensing optical fiber is 1.8 μg to 3 μg; The signal probe comprises oxidized gold platinum iron nanometal particles coupled with cTnI antibody II, and 35 μg to 45 μg of cTnI antibody II is added per 1 mg of oxidized gold platinum iron nanometal particles; The cTnI antibody 1 and cTnI antibody 2 can bind to different epitopes of cardiac troponin I.

2. The optical fiber signal sensing immunoassay kit according to claim 1, characterized in that: The amount of cTnI antibody added to each of the sensing optical fibers is 2 μg to 2.5 μg; preferably, the amount of cTnI antibody added to each of the sensing optical fibers is 2 μg to 2.2 μg.

3. The optical fiber signal sensing immunoassay kit according to claim 1, characterized in that: The amount of cTnI antibody II added per 1 mg of oxidized gold platinum iron nanometal particles is 38 μg to 42 μg.

4. The optical fiber signal sensing immunoassay kit according to claim 3, characterized in that: The amount of the signal probe added to each 1 μL of the test sample is 0.1 μg to 0.15 μg, preferably 0.1 μg to 0.125 μg.

5. The optical fiber signal sensing immunoassay kit according to claim 1, characterized in that: The clone number of the cTnI antibody 1 is 16A11cc; and / or, The clone number of the cTnI antibody II is 19C7cc.

6. The optical fiber signal sensing immunoassay kit according to any one of claims 1 to 5, characterized in that: The method for preparing the signal probe comprises the following steps: Mixing chloroauric acid, chloroplatinic acid and water to obtain a gold-platinic acid solution; reacting the gold platinum acid solution with aqueous ammonia to obtain a gold platinum acid solution; reacting the gold platinum acid solution with a ferrous chloride solution to obtain a gold platinum iron oxide nanoparticle suspension; The gold platinum iron oxide nanoparticle suspension is mixed with 1-ethyl-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide to perform an activation reaction to obtain an activated gold platinum iron oxide nanoparticle suspension; Add cTnI antibody 2 to the obtained activated oxidized gold platinum iron nanoparticle suspension for incubation; Adding blocking solution to the incubated solution to perform blocking reaction to obtain precipitation; The obtained precipitate is added into the labeling solution and mixed evenly to obtain the signal probe; Preferably, the concentration of the added ammonia solution is 0.4% w / v to 0.6% w / v, and the concentration of the added ferrous chloride solution is 0.4 mol / L to 0.6 mol / L; The dosage ratio of the chloroauric acid, chloroplatinic acid, ammonia water and ferrous chloride is 0.006mmol:0.006mmol:450μL~550μL:2mL~7mL; more preferably 0.006mmol:0.006mmol:480μL~520μL:2mL~4mL.

7. The optical fiber signal sensing immunoassay kit according to claim 6, characterized in that: The labeling solution contains 4% w / v to 6% w / v BSA, 0.3% w / v to 0.7% w / v T-20, 4% w / v to 6% w / v sucrose, and 18 mmol / L to 22 mmol / L Tris-HCl; and / or, The usage ratio of the gold platinum iron oxide nanoparticles, 1-ethyl-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide is 1 mg: 0.2 mg to 0.4 mg: 0.2 mg to 0.4 mg.

8. The optical fiber signal sensing immunoassay kit according to any one of claims 1 to 5, characterized in that: The preparation method of the capture probe comprises the following steps: Stripping the middle section of the sensing optical fiber to obtain a bare fiber section, and mixing the bare fiber section with a piranha solution to perform a hydroxylation treatment; The bare fiber segment after hydroxylation treatment is mixed with APTES solution for silanization treatment; The bare fiber segment after silanization treatment is mixed with glutaraldehyde solution to carry out aldehyde reaction; The bare fiber segment after the aldehyde reaction was mixed with the cTnI antibody and incubated; The incubated bare fiber segment is immersed in a blocking solution to perform a blocking reaction, and the capture probe is obtained after drying.

9. The optical fiber signal sensing immunoassay kit according to any one of claims 1 to 4, characterized in that: The optical fiber signal sensing immunoassay kit further comprises an optical fiber signal sensing immunoassay instrument; the optical fiber signal sensing immunoassay instrument comprises a box body and a laser; the box body has an embedding groove for inserting a mobile terminal, the first end of the sensing optical fiber is connected to the laser, the second end of the sensing optical fiber extends into the embedding groove and is used to transmit the optical fiber signal to the optical sensor of the mobile terminal; preferably, The output end of the laser is provided with a first optical fiber connector, and the box body is provided with a second optical fiber connector connected to the embedding groove; the first end of the sensing optical fiber is detachably connected to the first optical fiber connector, and the second end is detachably connected to the second optical fiber connector; and / or, A carrier is provided on one side of the box body away from the embedding groove, and a receiving groove for receiving the reaction container is provided on the carrier, and the receiving groove has opening structures at two opposite ends along the extending direction of the box body; and / or, The outer peripheral wall of the box body is provided with a groove, and the sensing optical fiber is detachably accommodated in the groove.

10. A method for detecting cardiac troponin for non-diagnostic purposes, characterized in that: The steps include: Mixing and incubating the sample to be tested with a signal probe, wherein the signal probe includes oxidized gold platinum iron nanoparticles coupled with cTnI antibody II; The incubated sample is mixed with a capture probe for incubation, wherein the capture probe comprises a sensing optical fiber and a cTnI antibody coupled to the sensing optical fiber; The light intensity value of the sensing optical fiber is measured by the optical sensor of the mobile terminal.

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