阅读说明：本技术 免疫检测方法 (Immunoassay method ) 是由 施志欣 吴和晋 李政亮 许纯渊 于 2019-12-11 设计创作，主要内容包括：本发明提供一种免疫检测方法,其包含：提供碟片；提供捕获抗体于基板上；添加样品于分流槽；施加第一转速,以从分流槽传送包含抗原的样品至反应槽；施加第二转速,以沉降样品于基板,使样品中的抗原与捕获抗体结合而获得第一复合物；利用毛细作用力,使样品从反应槽流出并填满流道；施加第三转速,以将样品从流道传送至废液槽；提供侦测抗体于基板上,使侦测抗体与第一复合物结合而获得第二复合物；以及检测第二复合物的来自局域性表面等离子体共振的光谱信号。(The invention provides an immunodetection method, which comprises the following steps: providing a disc; providing a capture antibody on a substrate; adding a sample into the shunting groove; applying a first rotational speed to transfer the sample comprising the antigen from the split channel to the reaction channel; applying a second rotation speed to settle the sample on the substrate, so that the antigen in the sample is combined with the capture antibody to obtain a first complex; enabling the sample to flow out of the reaction tank and fill the flow channel by using capillary force; applying a third rotational speed to transfer the sample from the flow channel to the waste reservoir; providing a detection antibody on the substrate, and enabling the detection antibody to be combined with the first compound to obtain a second compound; and detecting a spectral signal from the localized surface plasmon resonance of the second complex.)

1. An immunoassay method, comprising:

providing a disc, wherein the disc comprises a splitter and a plurality of disc units, and each disc unit comprises:

a reaction tank connected to the waste liquid tank by a flow path; and

the substrate is arranged in the reaction tank and is embedded with a plurality of first nano particles;

providing a capture antibody on the substrate;

adding a sample comprising an antigen to the split-flow channel;

applying a first rotational speed to move the sample in the shunt slot to the reaction slot;

applying a second rotation speed to settle the sample on the substrate, so that the antigen in the sample is combined with the capture antibody to obtain a first complex;

allowing the sample to flow out of the reaction groove by using capillary force and filling the flow channel;

applying a third rotational speed to move the sample from the flow channel to the waste reservoir;

providing a detection antibody on the substrate, and combining the detection antibody and the first complex into a second complex; and

detecting a spectroscopic signal of the second complex, wherein the spectroscopic signal is from localized surface plasmon resonances arising from the vibrations of the plurality of first nanoparticles;

wherein the second rotational speed is greater than the first rotational speed.

2. The immunoassay method of claim 1, wherein the third rotational velocity is greater than the first rotational velocity.

3. The immunoassay method of claim 1, wherein an end of the flow channel connected to the waste liquid tank extends in a direction passing through a center of the disk.

4. The immunoassay method of claim 1, wherein the detection antibody comprises a plurality of second nanoparticles, and wherein the plurality of first nanoparticles and the plurality of second nanoparticles vibrate to shift the wavelength of the spectral signal, thereby amplifying the spectral signal.

5. The immunoassay of claim 1, wherein at least one of the first plurality of nanoparticles and the second plurality of nanoparticles is a gold nanoparticle.

6. The immunoassay method of claim 1, wherein the first rotational speed is less than 1500 rpm.

7. The immunoassay method of claim 1, wherein said second rotation rate is greater than 2500 rpm.

8. The immunoassay of claim 1, further comprising a washing step comprising the steps of:

applying the first rotating speed to convey the cleaning solution from the diversion trench to the reaction trench;

enabling the cleaning solution to flow out of the reaction tank and fill the flow channel by using capillary force; and

applying the third rotational speed to convey the cleaning liquid from the flow path to the waste liquid tank.

9. The immunoassay method of claim 1, further comprising the step of providing a blocking agent on the substrate between the step of providing the capture antibody on the substrate and the step of providing the detection antibody on the substrate.

Technical Field

The present invention relates to an immunoassay method, and more particularly, to an immunoassay method of localized surface plasmon resonance capable of simplifying a step of injecting a reagent.

Background

Due to the advancement of medical science and technology, the life of people is prolonged. In various medical technologies, it is very important to provide a detection technique for medical data used to assist diagnosis. Currently, the detection technology and the detection instrument are concentrated in a large hospital, so that the subject needs to specially visit the hospital and go through a long detection process, and the detection willingness of the subject is reduced.

Therefore, Point-of-Care Testing (Point-of-Care Testing) can be performed more quickly. Among them, microfluidic disks (microfluidic disks) which are miniaturized, easy to carry, high in detection identification and convenient to operate are the mainstream products. Meanwhile, the micro-fluid disc can be matched with a centrifugal platform to reduce the reaction time.

For example, Enzyme-linked immunoassay (E L ISA) and microfluidic disc-like E L ISA (CD E L ISA) can reduce the overall detection time by the advantages of sequential release and uniform miniaturization of liquid, however, disc-like E L ISA has the disadvantages of insufficient sensitivity and complicated reagent injection steps.

Disclosure of Invention

In view of the above problems, an objective of the present invention is to provide an immunoassay method, which combines immunoassay, a micro-fluid disk, and a local surface plasmon resonance (L SPR) technology capable of amplifying optical signals, and uses a micro-fluid function matching program to automatically control the rotation speed of a motor, so as to simplify the steps of reagent injection, automatic liquid injection and liquid transfer.

The invention aims to provide an immunoassay method, which comprises the following steps: providing a disc, wherein the disc comprises a diversion channel and a plurality of disc units, each disc unit comprises a reaction tank connected to a waste liquid tank through a flow channel and a substrate arranged in the reaction tank, and the substrate is embedded with a plurality of first nano particles; providing a capture antibody (capture antibody) on a substrate; adding a sample into the shunting groove; applying a first rotational speed to transfer the sample containing the antigen (antigen) from the split channel to the reaction channel; applying a second rotation speed to settle the sample on the substrate, so that the antigen in the sample is combined with the capture antibody to obtain a first complex; enabling the sample to flow out of the reaction tank and fill the flow channel by using capillary force; applying a third rotational speed to transfer the sample from the flow channel to the waste reservoir; providing a detection antibody (detection antibody) on the substrate to bind the detection antibody and the first complex as a second complex; and detecting a spectral signal from the localized surface plasmon resonance of the second complex, the plurality of first nanoparticles vibrating to produce localized surface plasmon resonance. Wherein the second rotation speed is greater than the first rotation speed.

The immunodetection method of the invention has the following advantages:

(1) the method of the invention effectively and adjustably injects the reagent by changing the balance of the centrifugal force and the capillary force, and compared with the method of repeatedly injecting a plurality of reagents into the micro-titration plate by manpower, the method of the invention can simplify the manufacturing process, shorten the detection time and reduce the error and the cost of manual operation. Meanwhile, in the conventional disk design, the reaction tank and the disk unit are disposed on the same plane, but the problem of poor air discharge is easily caused. However, the reaction tank of the present invention is protruded in a radial direction, so that air can be effectively removed through a three-dimensional structure. The invention also adjusts the width of the connecting flow channel between the disc unit and the reaction tank on the plane, so that the disc has the advantages of smooth exhaust and small volume required by the reagent.

(2) The method of the invention uses the motor to control the rotating speed to completely remove and clean the liquid in the reaction tank, and uses the centrifugal force and the capillary force to evacuate the liquid to keep the surface of the substrate in a state close to dryness, so that the correct and stable data can be obtained during the subsequent optical detection.

Drawings

FIG. 1 is a schematic diagram of a disc according to a preferred embodiment of the present invention.

Fig. 2 is a partially enlarged view of a disc according to a preferred embodiment of the present invention.

FIG. 3 is a disc layout according to the preferred embodiment of the present invention.

FIG. 4 is a schematic diagram of a disc according to a preferred embodiment of the present invention.

FIG. 5 is a schematic diagram of a disc cleaning process according to a preferred embodiment of the present invention.

FIG. 6 is a schematic reaction scheme of a preferred embodiment of the present invention.

Fig. 7 is a schematic illustration of an aliquot of a preferred embodiment of the present invention.

FIG. 8 is an analytical chart of an aliquot of the present invention.

FIG. 9 is an analytical chart of an aliquot of the present invention.

FIG. 10 is a graph of angular velocity analysis of an aliquot of the present invention.

FIG. 11 is a graph of coefficient of variation analysis for aliquots of the invention.

FIG. 12 is a schematic view of an apparatus for quantifying an aliquot according to the present invention.

Fig. 13 is a schematic view of a liquid-filled flow channel according to the present invention.

Fig. 14 is a graph showing the rotational speed analysis of the filling liquid of the present invention.

FIG. 15 is a flow chart image of the fill liquid of the present invention.

FIG. 16 is an image of a liquid-filled reaction vessel according to the present invention.

Fig. 17 is a schematic view of a fluid evacuation flow path of the present invention.

FIG. 18 is an analysis of liquid evacuation according to the present invention.

Fig. 19 is a schematic view showing the arrangement of siphon flow path according to the present invention.

Fig. 20 is a key rotational speed analysis diagram of the siphon flow path of the present invention.

Fig. 21 is an image of residual moisture in the siphon flow path according to the present invention.

Fig. 22 is an analysis diagram of residual moisture in the siphon flow path of the present invention.

FIG. 23 is a schematic diagram of the detection area range according to the present invention.

FIG. 24 is an analysis chart of the incubation rotation speed of the present invention.

FIG. 25 is an analysis chart of the incubation rotation speed of the present invention.

FIG. 26 is an analysis chart of the number of washes in the present invention.

FIG. 27 is a graph of the accuracy analysis of the present invention.

Description of the symbols:

S51-S58, S601-S624: step (ii) of

1: disc

100. 400: disc unit

110. 410: splitter box

110 a: center of circle

120. 420, 2020: reaction tank

121: substrate

122: reaction zone

130. 430, 2030: waste liquid tank

140. 440, a step of: storage tank

150: flow passage

160: end part

2401: water film

2601. 2602: in part

401: equant plate

402: capillary tube

450: siphon channel

451: metering channel

452: connecting channel

453: exhaust passage

701: capture antibody

702: bovine serum albumin

703: antigens

704: detection of antibodies

D. L length

h. H: width of

Detailed Description

In order to make the aforementioned objects, technical features, and advantages of practical implementation easier for a person of ordinary skill in the art to understand, embodiments will be described in more detail below with reference to the drawings.

In one embodiment, a disk may be provided, which may include a diverter channel and a plurality of disk units. The number of disc units may be 8 or more. Each disk unit may include a reaction tank connected to the waste liquid tank by a flow path and a substrate disposed in the reaction tank. Each disk unit may include a storage slot. A plurality of first nanoparticles may be disposed on the substrate. The plurality of first nanoparticles may be gold nanoparticles or silver nanoparticles. The extending direction of the first part of the flow passage connected with the waste liquid groove passes through the circle center of the disc. A capture antibody may be provided on the substrate.

In one embodiment, a first rotation speed may be applied, and the centrifugal force generated by the first rotation speed may be used to drive the disk, so that the sample is transferred from the distribution groove to the reaction groove. The sample may comprise an antigen. A second rotational speed may be applied, and the sample may be settled on the substrate using centrifugal force generated by the second rotational speed, contacting the sample with the capture antibody, and allowing the antigen in the sample to specifically bind to the capture antibody as a first complex. Capillary force can be used to make the sample flow out of the reaction tank and fill the flow channel, but the sample does not overflow the flow channel, i.e. is not transferred to the waste liquid tank. A third rotational speed may be applied to transfer the sample from the flow channel to the waste reservoir using the euler force of the angular velocity caused by the third rotational speed.

In one embodiment, a detection antibody can be provided on the substrate to specifically bind the detection antibody to the first complex to detect a spectroscopic signal of localized surface plasmon resonance of the second complex. The plurality of first nanoparticles may vibrate to generate localized surface plasmon resonances. The detection antibody may comprise a plurality of second nanoparticles, and the plurality of first nanoparticles and the plurality of second nanoparticles may vibrate to shift the wavelength of the spectral signal, thereby amplifying the spectral signal to improve the sensitivity of the spectral signal.

After the capture antibody, the sample or the detection antibody are transmitted, the cleaning solution is transmitted to remove the residual liquid, so that the precision of the detection method is improved.

In one embodiment, between the step of providing the capture antibody on the substrate and the step of providing the detection antibody on the substrate, a step of providing a blocking agent on the substrate may be included. The capture antibody, antigen, detection antibody, wash solution and blocking agent can be capture antibody, antigen, detection antibody, wash solution and blocking agent known to those of ordinary skill in the art.

In a preferred embodiment of the invention, the immunodetection agents selected are as follows:

(A) single mouse anti-cardiac troponin I (Monoclonal mouse anti-cardiac tropin I, HyTest/19C7), concentration: 3.6 mg/ml.

(B) Recombinant human cardiac troponin I (Recombinant human cardiac troponin I, HyTest/8RTI7), concentration: 0.9 mg/ml.

(C) Single mouse anti-cardiac troponin I (Monoclonal mouse anti-cardiac tropin I, HyTest/16A11), concentration: 8.3 mg/ml.

(D) Phosphate buffer (BSA buffer).

(E)10 XPhosphate buffer (10 XPBS) comprising 80 g/L NaCl, 2 g/L KCl, 14.4 g/L NaHPO4 and 2.4 g/L KH2PO 4.

(F) Surfactant Tween-20

(G) Contains Phosphate buffer surfactant Tween-20(Phosphate Buffered SalineTween-20, PBST), which comprises 1 XPBS and Tween-20.

(H) And (4) edible pigment.

In a preferred embodiment of the invention, the microfluidic disc material is selected as follows:

(A) biocompatible adhesive tape (3M, usa).

(B) Polycarbonate (PC) fan test strips (taiwan, inc., kunjin industries, ltd.).

(C) Glass substrates with gold nanoparticles (Highua Crystal science, Inc., Taiwan).

(D) Micro titer plates (Highua Crystal science, Inc., Taiwan).

In a preferred embodiment of the present invention, the detailed operation steps are as follows.

Preparation and synthesis

The selected area is 0.07cm²The round glass plate is used as a substrate, and the concentration of the capture antibody is 3000ng/cm²And diluting the antigen concentration sequence to be 0, 64, 320, 1600, 8000, 40000 and 200000pg/m L, taking 1mM, 20m L tetrachloroauric acid solution, heating to boil, quickly adding 38.8mM, 2m L sodium citrate solution, heating to red solution color, obtaining gold nanoparticles (Au NPs), mixing every 100 mu L AuNPs with 1mg/ml, 1u L horseradish peroxidase (SA-HRP), and obtaining horseradish peroxidase-gold nanoparticles (SA-HRP Au NPs).

Disc design

Referring to fig. 1, the disc 1 has a splitter 110 disposed at the center of the disc and 8 disc units 100. When the disc 1 is circular, the disc has a center 110A. The distribution groove 110 connects all the disk units 100 to equally distribute the reagent (aliquoting). The disk unit 100 has a reaction tank 120, a waste liquid tank 130, a storage tank 140, and a flow channel 150. A substrate coated with gold nanoparticles is disposed in the reaction tank 120. First, the reagents are temporarily stored in the storage tank 140, and then, each reagent is reacted in the reaction tank 120 by centrifugal force, flows out of the reaction tank by capillary phenomenon and fills the flow channel 150, and then, is transferred to the waste liquid tank 130 by centrifugal force. Therefore, the user only needs a single injection of the reagent, so that the reagent can be automatically and equally distributed into the plurality of reaction chambers 120, and the reagent can be kept in the reaction chambers 120 for incubation, so that the reagent can be coated on the substrate.

Referring to FIG. 2, (A) is a front view of the reaction chamber, (B) and (C) are side views of the reaction chamber, length L is the minimum length that can be detected by rotation on the centrifugal stage, length D is the diameter of the detection area, length L can be more than 1mm, if less than 1mm, no detection by rotation is possible, if more than 10mm, a negative effect of using a large volume of reagent is produced, and a substrate 121 is disposed in the reaction chamber 120 to form the reaction region 122.

Referring to FIG. 3, since the substrates can be disposed at different positions in the reaction vessel, the effects of the disposed positions on the detection were compared in three types of Type A, Type B and Type C, respectively, and the results are shown in Table 1.

TABLE 1

	Type A	Type B	Type C
				Required volume of reagent	Multiple purpose	Chinese character shao (a Chinese character of 'shao')	Chinese character shao (a Chinese character of 'shao')
Effect of exclusion of reagents	No residue liquid	With residual liquid	No residue liquid
				The result of the detection	There is a trend toward	Has no obvious trend	There is a trend toward

Referring to table 1, it is seen that the Type C setting method requires a small volume of reagent, easily removes the reagent, and hardly causes the reagent to remain, and the test results tend to be similar. Therefore, Type C is selected.

And then, providing PMMA processed by an engraving machine, so that a flow channel exists on the PMMA, and obtaining the disc unit. Referring to fig. 4, (a) is a schematic view of a disc, (B) is a schematic view of a disc unit, (C) is a partially enlarged schematic view of the disc unit, and (D) is a real view of the disc unit.

As shown in (a), the disc includes a bisecting disc 401 and 8 disc units 400. The trisection plate 401 includes a central dividing groove 410, 8 capillaries 402 are provided on the outer periphery of the trisection plate 401, and the capillaries 402 are connected to the disc unit 400 and deliver the aliquoted liquid to the disc unit 400. As shown in (B), the disk unit 400 includes a planar microfluidic structure protruding in the axial direction and a reaction groove 420. The planar microfluidic structure includes a reservoir 440, a connecting channel 452 for connecting to the reaction chamber, a metering channel 451, a siphon channel 450, an exhaust channel 453, and a waste liquid tank 430. As shown in (C), the reaction tank 420 disposed radially includes a glass substrate 421 coated with gold nanoparticles and a plastic cap 423.

Comparative example

Replacing the micro-titer plate made of transparent plastic material at the bottom of the micro-titer plate with the glass substrate coated with the nano-gold particles, and performing immunoadsorption reaction, as follows:

(1) the capture antibody was coated on the glass with gold nanoparticles by 60W microwave for 30 minutes, the reagent was removed and washed 4 times.

(2) Bovine Serum Albumin (BSA), antigen, and detection antibody labeled with gold nanoparticles are sequentially added to the microtiter plate, and the plate is spun at 2700rpm for 20 minutes to deposit on the glass at the bottom of the well plate, and after the deposition, the reagent is removed and washed 4 times.

(3) The hole plate is turned over 180 degrees, the liquid is dried by high-speed centrifugation to reduce surface water stain, and optical measurement is carried out at the wavelength of 550 nm.

Examples of the invention

The L SPR technique was integrated into a microfluidic centrifugal platform on which centrifugation, sedimentation and removal of reagents were performed and followed by detection in an optical instrument, as detailed below:

(1) coating step

The capture antibody was transferred to the reaction tank at a low rotation speed of 1000rpm and then coated on the glass with gold nanoparticles by a microwave of 60W for 30 minutes. The rotation speed was increased to 2700rpm to remove the unbound capture antibody to the waste liquid tank. And adding PBST serving as a cleaning solution into the storage tank, driving the reagent to the reaction tank at a low rotation speed of 1000rpm for cleaning, and enabling the PBST to pass through the siphon flow channel after the cleaning is finished. Finally, the speed was increased to 2700rpm to discharge PBST to the waste liquid tank.

(2) Cultivating and cleaning:

bovine serum albumin was transferred to the reaction tank by centrifugation at 1000rpm and sedimented on glass by centrifugation at 2700rpm for 20 minutes. After completion, the rotation speed is increased to 2700rpm to discharge the unbound bovine serum albumin to the waste liquid tank. And then adding PBST into the storage tank, driving the PBST at a low rotation speed of 1000rpm until the reaction tank is cleaned, and enabling the PBST to pass through the siphon flow channel after the cleaning is finished. Finally, the speed was increased to 2700rpm to discharge PBST to the waste liquid tank. And settling the antigen and the SA-HRP @ Au NPs respectively by using the same centrifugation speed, centrifugation time and centrifugation times.

(3) A detection step:

the disc was examined on an optical instrument at a wavelength of 550 nm.

Refer to fig. 5 and 6. S51-S54 are injecting the reagent, filling the reagent, then climbing the reagent to empty the reagent, S55-58 are injecting the cleaning solution to fill the cleaning solution, and then climbing the cleaning solution to empty the cleaning solution.

In steps S601 to S603, the capture antibody is bound to the substrate in the reaction chamber 620. Steps S604 to S606 remove the capture antibody not bound to the substrate with a washing solution. Steps S607 to S609 provide a barrier agent on the substrate. In steps S610 to S612, the blocking agent not bonded to the substrate is removed by a cleaning solution. In steps S613 to S615, the antigen and the capture antibody are bound. In steps S616 to S618, the antigen not bound to the capture antibody is removed by the washing solution. Step S619 to S621, the detection antibody and the antigen are combined to form a sandwich structure of the detection antibody-antigen-capture antibody. In steps S622 to S624, the detection antibody not bound to the antigen is removed by a washing solution.

Next, the comparative examples and examples were analyzed.

Analysis of one, one aliquot of sample

Reference is made to fig. 7, which is a schematic illustration of an aliquot of a preferred embodiment of the present invention. Represents a reagent which only needs to be injected once, and can reduce the whole injection times of the test so as to greatly save time and labor. When channels with different diameters are selected, the time for the liquid to break through the channels is different, and the error is caused by filling in the theta direction. The larger the angular acceleration is, the smaller the time difference of the liquid filling the groove body and breaking through the channel is, and the variation of the volume of the liquid is small.

Referring to fig. 8, (a) is an analysis graph of angular acceleration against liquid diversion, and (B) is an analysis graph of angular acceleration against a breakthrough time difference. As shown in (A), it is found that when the depth of the groove body is 0.5mm, the resistance is large because the depth is small, the time for filling the central diversion groove is long, and the coefficient of variation is high. As shown in (B), it was found that when the depth of the groove body was sufficient, the time required to fill the central manifold body was short.

Next, the flow rate error analysis was performed by selecting the channels with diameters of 0.2, 0.4 and 0.8mm, and the results are shown in fig. 9. It can be seen that the error of the volume amounts flowing out at the first and last channels is small when connecting with smaller channels. Therefore, the tube diameter of the fixed channel is 0.2mm, and the results of analyzing the breakthrough time difference, the flow rate and the coefficient of variation are shown in fig. 10 and 11.

Referring to fig. 10, (a) is an analysis diagram of the difference in breakthrough time between the angular accelerations, and (B) is an analysis diagram of the flow rate between the angular accelerations.

Referring to fig. 11, which is a graph of coefficient of variation analysis of an aliquot of the present invention, the value obtained by multiplying Δ t and Qr at each angular acceleration is related to the coefficient of variation c.v. The angular acceleration when improving the motor and accelerating can reduce the time of filling central splitter box, makes the syringe needle front end and break through the outflow fast filled up to liquid, if use narrower passageway simultaneously, can make the equivalent distribution coefficient of variation of reposition of redundant personnel of liquid can control in 3 ~ 5%.

Referring to FIG. 12, (A) and (B) are discs with and without dosing devices, respectively. Due to errors in aliquotting, all reagents may be discharged to the waste liquid tank. Therefore, a quantitative device is added beside the reaction tank to flow the excess reagent to the waste liquid tank.

Analysis II, filling liquid

If the inlet flow channel is designed to be wider and deeper, the flow channel resistance is small and the flow rate is increased, liquid flows into the reaction tank quickly, the exhaust channel is blocked, the exhaust cannot be performed, the reaction tank is difficult to be completely filled, liquid accumulation is generated, the height of the liquid in the flow channel is higher than that of the siphon flow channel, and all the liquid is discharged into the waste liquid tank. Therefore, the present invention overcomes the problem of air removal by using the radially protruding reaction grooves 423 as shown in fig. 4(C) and the ratio of the liquid width H to the width H of the connecting channel.

Referring to fig. 13, the width of the liquid flowing out of the inlet channel is defined as width H, the width of the connecting channel is defined as width H, and different ratios (H/H) are provided at different rotation speeds. Wherein, the width H of the connecting channel represents the inlet width of the reaction tank.

The hydraulic diameter of the inlet channel of the fixed liquid flowing into the reaction tank was 0.4mm, the rotation speed was changed to 1000, 2000, 3000, 4000 and 5000rpm, and the H/H was 0.2, 0.4, 0.6, 0.8 and 1.0mm, and the results of examining the flow rate at each rotation speed are shown in fig. 14.

It is known that the volume flow into the reactor is of great importance in the filling process. At low volumetric flow rates (Q <300), the reaction tank is completely filled with liquid, the venting is good, and excess liquid overflows through the metering channel to the waste tank. At moderate volumetric flow rates (300< Q <900), the reaction chamber is poorly evacuated by air and is not completely filled with liquid, which flows through the top of the capillary tube and into the waste reservoir, while excess liquid also flows into the waste reservoir through the metering channel. At high volumetric flow rates (900< Q), large bubbles were observed in the connecting channel that prevented liquid flow into the reaction chamber, most of the liquid flowed into the waste reservoir, and the reaction chamber was not filled. It is known that the filling effect varies according to the fluid design and is additionally related to the ratio (H/H). If the ratio (H/H) is less than 0.3, successful filling can be achieved.

Referring to FIG. 15, (A), (B) and (C) are images of stream at 1000rpm, 2000rpm to 4000rpm and 5000rpm, respectively.

As shown in (A), the liquid is smoothly exhausted and successfully retained. As shown in (B), the continuous liquid takes up the volume of liquid to be filled with bubbles, and the liquid is discharged to the waste liquid tank by siphoning. As shown in (C), the vent valve is blocked, so that the reaction tank cannot be filled with liquid, the filled reaction tank fails, and the liquid is discharged to the waste liquid tank.

Referring to FIG. 16, (A) and (B) are a top view and a side view of the reactor at 1000rpm, respectively, and (C) and (D) are a top view and a side view of the reactor at 5000rpm, respectively. When the rotation speed was 1000rpm, the liquid was smoothly filled in the reaction vessel, and when the rotation speed was increased to 5000rpm, the liquid was not filled in the reaction vessel.

Analysis III, liquid evacuation

Referring to fig. 17, (a) is a schematic view of liquid evacuation with hydrophilic surface treatment, (B) is a schematic view of liquid evacuation without hydrophilic surface treatment, and (C) is a schematic view of flow channels for liquid evacuation.

As shown in (A), the liquid automatically passes through the highest point of the siphon flow channel under the siphon action and reaches the waste liquid tank, the rotating speed of the motor is increased, and the liquid in the reaction tank can be carried to the waste liquid tank along with the liquid in the connecting channel. However, the effect of the surface treatment is ineffective with time. As shown in (B), in order to avoid the reagent from directly entering the waste liquid tank through the siphon channel, there is a radial difference Δ R between the reaction tank and the overflow point of the siphon channel. The radial difference Δ R is defined as the difference between the equilibrium water level after centrifugation and the highest point of the siphon. A safe accumulation height is set according to the radial difference ar to avoid liquid from entering the waste tank directly through the siphon channel and to enable liquid actuation. The distance of movement of the liquid through the surface of the unmodified flow channel in elevation is dependent on the angular acceleration of the motor and the hydraulic diameter d of the flow channel_HAnd the liquid is lifted by momentum under the action of changing the rotating speed. As shown in (C), the length of the flow path is at a high rotational speed (ω)_H>2000rpm) above the liquid level in the reaction vessel, and has a width and depth of 0.4 mm. When the motor rotates to a high rotating speed, the liquid enters the reaction tank under the driving of centrifugal force; then the motor speed is reduced to a low speed (omega)_L<10rpm) when the centrifugal force is smaller than the capillary force, the liquid in the flow channel is driven by the capillary force to fill the flow channel;finally, the motor is raised to a high rotating speed, and the liquid in the reaction tank is discharged to the waste liquid tank due to the siphonage phenomenon.

The rotation speed was set at 4000rpm, the rotation speed was then decreased to 0rpm, the angular acceleration was set at 10000, 40000, 70000, 100000rpm/s, the inclination angle was set at 15, 30, 45 degrees, and the height of liquid elevation was observed, and the results are shown in fig. 18.

Referring to fig. 18, (a) is an angular acceleration analysis chart, and (B) is an inclination analysis chart. It is known that higher angular acceleration produces greater euler force and the height of liquid lift increases accordingly. The greater the hydraulic diameter, the lower the resistance, the greater the liquid lifting height, and vice versa. Meanwhile, the angle of the inclination angle affects the angular acceleration required for lifting, and the larger the angle of the inclination angle is, the larger the lifting height of the liquid is, and vice versa.

Even if the liquid is discharged to the waste liquid tank through the highest point of the siphon channel, if the applied rotating speed does not reach the critical rotating speed, the liquid still remains in the flow channel connected with the front end of the waste liquid tank, so that after the liquid is injected and centrifuged subsequently, the liquid can be directly discharged to the waste liquid tank, and the liquid cannot be reserved for centrifugal sedimentation cultivation. Therefore, the method is analyzed according to the arrangement mode of the siphon flow channel.

Referring to fig. 19, (a) and (B) are respectively design 1 and design 2 of the siphon flow channel, and the analysis result is shown in fig. 20, when the hydraulic diameter of the siphon flow channel for liquid evacuation is larger, the key rotation speed for liquid evacuation is reduced due to smaller resistance; and vice versa. Meanwhile, it can be seen that the extension direction of the siphon channel of design 2 is a centrifugal direction, i.e. the extension direction of the end 160 of the flow channel 150 connected to the waste liquid tank 130 passes through the center 110A of the disc, so the key rotation speed is lower than that of the siphon channel of design 1.

Since the glass surface needs to be dried when L SPR sensing is performed, in the present invention, the liquid in the reaction tank is drained to the waste liquid tank through the siphon channel by using the liquid draining method.

Referring to fig. 21, it is seen that water film 2401 is formed due to residual moisture on the glass surface. Then, the substrate with the water film and completely dried was analyzed, and as a result, as shown in fig. 22, the signal was slightly increased by the water film, which is similar to the completely dried result.

Volume of assay III, reagent

The absorbance (o.d.) of Anti IgG-HRP @ Au NPs was fixed, the more STD volume added at the same concentration of STD, the higher the final data, the experiment related to the height of reagent deposited vertically on the bottom sensing glass, and the results are shown in fig. 23.

Referring to FIG. 23, (A) shows that the incubation height of the reagent is height H1, (B) shows the specific size of the example of the present invention, in which the length L of the minimum length of the rotation detection on the centrifugal platform is 10mm, the length D of the diameter of the detection area is 3mm, and the height H1 of the incubation height of the reagent is 3mm, wherein the volume V of the required reagent is_totalIs the volume V of the reaction tank_chamberVolume V of connecting channel_channelAnd flow channel volume V_{disk channel}The sum of (a) and (b). Volume V of reaction tank_chamberThe circular area is multiplied by the thickness, and the length D of the diameter of the original design (as shown in (C)) is 6; and the length D of the new design (as shown in (D)) is 3. Volume V of connecting channel_channelThe rectangular area multiplied by the thickness, the length L of the original design and the new design are both 10, and the thickness is 4. the flow channel volume V_{disk channel}Then the sum of the volumes of portions 2601 and 2602 (as shown in (E)), the volume of portion 2601 is the length times the width and then the depth; the volume of portion 2602 is the volume of the siphon flow path, and its volume is set to 1. The embodiment of the invention can effectively reduce the dosage of the reagent.

Meanwhile, the comparative examples and examples were analyzed for the volume of the reagents required, and the results are shown in table 2.

TABLE 2

Reagent volume (μ L)	Comparative example	Examples of the invention
			Capture antibody	100	71
Barrier agent	100	71
			Antigens	100	71
Detection of antibodies	100	71
			Cleaning liquid	1600	284

As shown in table 2, it is understood that the examples of the present invention can greatly reduce the volume of the reagent used.

Fifth, analysis, incubation speed and time of reagent

The incubation time was 20 minutes, and the rotation speed of 2700rpm was selected as the optimum centrifugal sedimentation incubation rotation speed, the antigen concentration sequence was diluted to 0, 64, 320, 1600, 8000, 40000, 200000pg/m L for detection on the centrifugal immunoassay analyzer, and the results are shown in FIG. 24, which indicates that there was still a difference in absorbance between the comparative example and the example.

Referring to FIG. 25, it can be seen that increasing the rotational speed raises the signal. When the incubation time is 10 minutes or 20 minutes, no increase is added to the signal when the centrifugation sedimentation incubation is performed at 5000rpm, and therefore, the centrifugation sedimentation incubation is performed at 5000rpm for 10 minutes.

Sixth, washing of reaction

The immunoadsorption reaction detection needs to be cleaned for many times so as to avoid the adsorption of non-abnormal proteins or the residues in the reaction tank. Therefore, the effect of the cleaning pass was analyzed. After sedimentation, the reagent was removed and washed 1 and 4 times with washing solution PBST, respectively, and the results are shown in FIG. 26. It can be seen that the signal of 1 wash is slightly greater than the signal of 4 washes, but the difference is not great.

Analysis seven, precision

The results of the analyses of the examples of the present invention and the comparative examples are shown in fig. 27. It can be seen that the examples of the present invention tended to be similar to the comparative examples, and thus the analytical capabilities of the examples were similar to those of the microtiter plates.

In summary, although the present invention has been described with the above embodiments and examples specifically for the immunoassay method of the present invention, it will be understood by those skilled in the art that modifications and variations can be made to the embodiments without departing from the technical principles and spirit of the present invention. Therefore, the scope of the invention is to be determined by the following claims.