Test paper for detecting estrone and method for preparing the same

Abstract

The application discloses a test paper for detecting estrone and a preparation method thereof, which comprises the following steps: (1) preparing a CsYF4@Yb2O3 compound, adsorbing estrone antibodies, i.e. first antibodies, on the surface of the compound to obtain a photothermal signal probe; (2) assembling a test paper strip, fixing estrone antigens and second antibodies on a detection area and a quality control area respectively; (3) mixing the photothermal signal probe with a sample liquid to be detected, and then inserting a sample pad end of the test paper strip into the mixed liquid to perform chromatography; and (4) detecting a photothermal signal: irradiating the detection area with a near-infrared LED, collecting temperature by using a thermal imaging or temperature measuring device, and performing quantitative analysis according to a linear relationship between the temperature of the detection area and the estrone concentration of the sample. The detection mode is flexible, has a wide linear range, high sensitivity and good specificity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of small molecule analysis and detection, and particularly relates to a test paper for detecting estrone and a preparation method thereof. BACKGROUND

[0002] Lateral flow immunoassay (LFIA) has the characteristics of fast analysis performance, good selectivity, low cost, small sample requirement, easy mass production and stable long-term storage, and is widely used in the design of portable analysis and detection sensors. Compared with the colorimetric mode, the light-thermal type lateral flow immunoassay (LFIA) using light-thermal signal probes has an increase of several tens to hundreds of times in sensitivity. The signal of this detection method is caused by temperature change due to light-thermal effect, and the background signal is low, the sensing sensitivity is high, and it can be performed on various substrates of different colors, and has strong application potential. At present, there is still a need for new nanomaterials with higher light-thermal conversion efficiency as light-thermal signal probes to form more obvious thermal contrast, so as to further improve the performance of light-thermal LFIA.

[0003] Fluorides generally have lower phonon energy and higher light transmittance, which is beneficial to reduce light scattering and improve light utilization. In terms of light-thermal conversion, fluoride matrix may contribute to the absorption and conversion of photons, thereby improving the light-thermal efficiency. Yb2O3 is a rare earth oxide with excellent thermal stability and chemical stability. In the field of optics, Yb2O3 is often used as an additive of optical materials to improve the light transmittance and light-thermal conversion efficiency of the materials. SUMMARY

[0004] In view of the above problems existing in the prior art, the present application provides a test paper for detecting estrone and a preparation method thereof, and a CsYF4@Yb2O3 composite material is used to prepare a light-thermal test paper strip for detecting estrone. The test paper strip of the present application is used to detect estrone, and the detection limit is as low as 10 -1 pg / mL.

[0005] The technical scheme of the present application is as follows:

[0006] The first object of the present application is to provide a CsYF4@Yb2O3 composite material, and the preparation method of the composite material comprises the following steps:

[0007] (1) Y(NO3)3 and Yb2O3 are mixed in an aqueous ethylenediaminetetraacetic acid solution, and under stirring, NH4F solution and CsF solution are sequentially added, and stirring is continued until a milky white solution is generated;

[0008] (2) The milky white solution is reacted at high temperature, and after the reaction is completed, it is cooled to room temperature, and then washed and dried to obtain the CsYF4@Yb2O3 composite material.

[0009] In one embodiment of the present invention, in step (1), one or more of the following conditions are met:

[0010] The molar ratio of Y(NO3)3 to Yb2O is 1:10-10:1;

[0011] The concentration of the aqueous solution of ethylenediaminetetraacetic acid is 5-7 mg / mL;

[0012] The concentration of the NH4F solution is 0.8-1.2 mol / L;

[0013] The concentration of CsF solution is 0.8-1.2 mol / L;

[0014] The molar ratio of Y(NO3)3 to CsF is 1:5-5:1;

[0015] The stirring reaction conditions are room temperature and time of 5-30 minutes.

[0016] In one embodiment of the present invention, in step (2), one or more of the following conditions are met:

[0017] The high-temperature reaction is carried out at a temperature of 160-250℃ for 12-36 hours.

[0018] The cleaning process involves alternating between ultrapure water and alcohol 2-3 times.

[0019] Drying is carried out at 50-80℃ for 1-4 hours.

[0020] In one embodiment of the present invention, the specific method for producing the CsYF4@Yb2O3 composite material is as follows: 140-160 mg of ethylenediaminetetraacetic acid (EDTA) is added to a 50 mL beaker, and 25 mL of ultrapure water is added and stirred rapidly for 5 minutes. Then, 0.8-1.0 mL of Y(NO3)3 with a molar concentration of 0.6-0.8 mol / L and 0.1-0.3 mL of Yb2O3 aqueous solution (containing 5% nitric acid) with a molar concentration of 0.6-0.8 mol / L are added, and the mixture is stirred rapidly for 30 minutes. Subsequently, 2-4 mL of NH4F with a molar concentration of 0.8-1.2 mol / L and 2-4 mL of CsF with a molar concentration of 0.8-1.2 mol / L are added, and the mixture is stirred continuously for 30 minutes until a milky white solution is produced. After transferring the solution to a high-pressure reactor at 200℃, the reaction was allowed to proceed for 24 hours. The mixture was then cooled to room temperature, washed 2-3 times alternately with ultrapure water and alcohol, and dried at 70℃ for 2 hours to obtain the CsYF4@Yb2O3 nanocomposite material. It was then dried for further use.

[0021] The second objective of this invention is to provide an application of the above-mentioned CsYF4@Yb2O3 composite material for the preparation of photothermal signal probes.

[0022] The third objective of this invention is to provide a photothermal signal probe prepared from the above-mentioned CsYF4@Yb2O3 composite material, containing the CsYF4@Yb2O3 composite material, estrone antibody, and bovine serum albumin.

[0023] In one embodiment of the present invention, the photothermal signal probe preparation method is as follows: CsYF4@Yb2O3 composite material is mixed with analyte antibody and bovine serum albumin to obtain CsYF4@Yb2O3-mAb mixture.

[0024] In one embodiment of the present invention, CsYF4@Yb2O3 composite material is placed in a centrifuge tube, a weak alkaline solution is added to adjust the pH of the system to 6-8, the mixture is shaken and mixed, then estrone antibody is added, and the mixture is shaken and reacted at room temperature for 30-60 min. Bovine serum albumin (BSA) is added for blocking, and the mixture is shaken and reacted at room temperature for 1-1.5 h. After centrifugation, the supernatant is removed, and the remaining substance is reconstituted in buffer solution to obtain CsYF4@Yb2O3-mAb mixture, which is then refrigerated for later use.

[0025] In one embodiment of the present invention, the buffer solution is a phosphate buffer, a borate buffer, or a carbonate buffer.

[0026] A fourth objective of this invention is to provide a test strip containing the aforementioned photothermal signal probe, the test strip comprising a photothermal signal probe and a test strip body;

[0027] The photothermal signal probe is prepared by modifying a CsYF4@Yb2O3 composite material with an estrone monoclonal or polyclonal antibody, and is used in a form independent of the main structure of the photothermal test strip or in a form dried on the conjugate pad.

[0028] The main body of the test strip includes a PVC base plate, a sample pad, a nitrocellulose membrane (NC membrane), and an absorbent pad.

[0029] In one embodiment of the present invention, the test strip body comprises: a sample pad, a nitrocellulose membrane (NC membrane), and an absorbent pad, which are sequentially and alternately pasted from top to bottom in a horizontal direction on a PVC base plate; wherein, the nitrocellulose membrane is used to separate and detect analytes from other substances in the sample, the sample pad is used for sample loading, the absorbent pad is used to absorb excess liquid, and the PVC base plate provides physical support for the test strip; the nitrocellulose membrane includes a detection zone (T zone) and a control zone (C zone); wherein, estrone antigen, i.e., the analyte-protein conjugate, is immobilized on the T zone; and a secondary antibody, i.e., an anti-primary antibody, is immobilized on the C zone;

[0030] The photothermal signal probe can be used independently of the main structure of the photothermal test strip, or the photothermal signal probe can be dried on the conjugate pad and the conjugate pad can be inserted between the sample pad and the NC membrane.

[0031] In one embodiment of the present invention, the estrone antibody, i.e., the primary antibody, is derived from at least one of mice, rats, and rabbits.

[0032] In one embodiment of the present invention, the secondary antibody includes at least one of sheep anti-mouse secondary antibody, rabbit anti-mouse secondary antibody, sheep anti-rabbit secondary antibody, and donkey anti-rabbit secondary antibody.

[0033] The fifth object of the present invention is to provide a method for preparing the above-mentioned test strip, comprising the following steps:

[0034] Preparation of CsYF4@Yb2O3 composite materials;

[0035] Preparation of CsYF4@Yb2O3 composite material, estrone antibody, and bovine serum albumin CsYF4@Yb2O3-mAb mixture;

[0036] Constructing the test strip: Add or spray estrone antigen to the T zone, and add or spray secondary antibody against the primary antibody (i.e., anti-primary antibody) to the C zone. After drying, store in a vacuum bag for later use.

[0037] The photothermal signal probe, namely the CsYF4@Yb2O3-mAb mixture, is stored in a sealed container as a solution or lyophilized powder; or the photothermal signal probe, namely the CsYF4@Yb2O3-mAb mixture, is dried on the binding pad and the binding pad is inserted between the sample pad and the NC membrane for use.

[0038] In one embodiment of the present invention, the addition or spraying of estrone antigen to the T region specifically involves adding or spraying a 5-20 mM PBS solution containing 0.5-10 mg / mL estrone antigen to the T region; the addition or spraying of a secondary antibody against the primary antibody, i.e., anti-primary antibody, to the C region specifically involves adding or spraying a 5-20 mM PBS solution containing 0.05-10 mg / mL secondary antibody to the C region.

[0039] The sixth objective of this invention is to provide an application of the above-mentioned test strip for detecting estrone; the photothermal temperature of the detection area is negatively correlated with the estrone content to be measured, and the color intensity is negatively correlated with the estrone content in the sample, specifically:

[0040] When the sample does not contain estrone, the T region appears purple and the temperature is high.

[0041] When the sample contains estrone, the T region appears light purple or even disappears, and the temperature decreases.

[0042] The quality control area, which serves as a reference for verifying the validity of the test strip results, always appears purple.

[0043] The sixth objective of this invention is to provide a test strip for detecting estrone, comprising a photothermal signal probe and a test strip body;

[0044] The photothermal signal probe contains a mixture of CsYF4@Yb2O3 composite material, estrone antibody (primary antibody), and bovine serum albumin, namely CsYF4@Yb2O3-mAb mixture;

[0045] The main body of the test strip comprises: a sample pad, a nitrocellulose membrane (NC membrane), and an absorbent pad, which are horizontally overlapped and pasted from top to bottom on a PVC base plate; wherein, the nitrocellulose membrane is used to separate and detect analytes from other substances in the sample, the sample pad is used for sample loading, the absorbent pad is used to absorb excess liquid, and the PVC base plate provides physical support for the test strip; the nitrocellulose membrane includes a detection zone (T zone) and a control zone (C zone); wherein, the T zone is immobilized with estrone antigen, i.e., the analyte-protein conjugate; the C zone is immobilized with a secondary antibody, which is a secondary antibody against the primary antibody, i.e., an anti-primary antibody;

[0046] The photothermal signal probe can be used independently of the main structure of the photothermal test strip, or the photothermal signal probe can be dried on the conjugate pad and the conjugate pad can be inserted between the sample pad and the NC membrane.

[0047] In one embodiment of the present invention, the method for detecting estrone using test strips includes the following steps:

[0048] When the photothermal signal probe is used independently of the main structure of the photothermal test strip, it specifically includes:

[0049] Mix the sample to be tested with CsYF4@Yb2O3-mAb solution in the running buffer for 3-10 min, and then place the test strip in the buffer. After 15-30 min, read the colorimetric results and perform semi-quantitative analysis. Obtain a photograph of the colorimetric results and perform grayscale analysis using image processing software to perform quantitative analysis.

[0050] When the photothermal signal probe is dried on the conjugate pad and the conjugate pad is inserted between the sample pad and the NC membrane in the main body structure of the test strip, the specific steps include:

[0051] The sample to be tested is mixed with the running buffer solution, placed into the test strip, and the colorimetric result is read after 20-40 minutes. A colorimetric result image is obtained for semi-quantitative analysis; grayscale analysis is performed using image processing software for quantitative analysis.

[0052] After the test strip is dried, it is placed under a near-infrared LED light source for excitation. The temperature result is obtained using a thermal imaging or temperature measuring device and a smart display terminal. The thermal imaging or temperature measuring device includes at least one of a mobile phone infrared thermal imaging analysis accessory, an infrared thermal imager, and a temperature gun. The smart display terminal includes at least one of a computer and a smartphone. The thermal imaging device acquires photothermal imaging photos and outputs and displays them through the connected smart display terminal.

[0053] In one embodiment of the present invention, the running buffer is a PBS solution with pH 6.5 to 8.0 and a total concentration of 10 mM, and the following components are in mass percentage, specifically including: 0 to 15% sucrose, 1 to 10% BSA, and 0.15 to 1% Tween-20.

[0054] In one embodiment of the present invention, the wavelength of the near-infrared LED light source is 980nm.

[0055] The detection principle of the photothermal test strip for estrone detection in this invention is as follows: The control zone (zone C) serves as a reference for verifying the validity of the test strip results and always appears purple. After the sample solution and CsYF4@Yb2O3-mAb are premixed, they move towards the absorbent paper under capillary action. When there is no estrone in the sample, CsYF4@Yb2O3-mAb is captured by estrone-BSA in zone T, and zone T appears purple to the naked eye. Under laser excitation, CsYF4@Yb2O3-mAb exhibits an LSPR effect, and the temperature rises. Excess CsYF4@Yb2O3-mAb is captured by the secondary antibody in zone C, so zone C also appears purple. When the sample contains estrone, estrone binds to some of the CsYF4@Yb2O3-mAb, thereby reducing the total amount of CsYF4@Yb2O3-mAb captured in zone T. The LSPR effect of CsYF4@Yb2O3-mAb in zone T decreases or even disappears, and the temperature drops. As the concentration of estrone in the sample increases, less and less CsYF4@Yb2O3-mAb is captured in the T region, and the temperature in the T region gradually decreases, which is inversely proportional to the concentration of the analyte.

[0056] The beneficial technical effects of this invention are as follows:

[0057] The CsYF4@Yb2O3 composite material provided by this invention can be used in the preparation and application of photothermal test strips without changing the conventional structure of the test strips. It can be used as a photothermal signal probe, and can be used independently of the aforementioned photothermal test strip form for easy storage, or it can be fixed to the bonding pad of the test strip for easy carrying.

[0058] The detection method provided by this invention, which includes a photothermal test strip, is used to detect estrone. The photothermal test strip is based on the plasma resonance effect, using a CsYF4@Yb2O3 composite material with high photothermal conversion efficiency and small size as a T-zone fixed photothermal signal probe. It is excited by a near-infrared LED light source and combined with a smart terminal and infrared thermal imaging accessories to realize the acquisition of photothermal signals. This effectively removes the color of the sample liquid base and the interference of the test strip fluorescence background, thereby improving the signal-to-noise ratio.

[0059] The testing method provided by this invention has a lower detection limit, a wider detection range, and better specificity. It is more sensitive than other photothermal test strips and is suitable for the rapid detection of estrone. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of the photothermal test strip of the present invention;

[0061] Figure 2 The scanning electron microscope image and particle size distribution diagram of the CsYF4@Yb2O3 composite material in the photothermal signal probe of the test strip of the present invention are shown.

[0062] Figure 3 This invention illustrates the photothermal temperature variations of the CsYF4@Yb2O3 composite material, CsYF4, and Yb2O3 in the photothermal signal probe of the test strip.

[0063] Figure 4 This is a diagram showing the response of the test strip of the present invention to water samples of different concentrations of estrone under photothermal mode;

[0064] Figure 5 This is a diagram showing the response of the test strip of the present invention to estrone and four other estrogens. Detailed Implementation

[0065] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0066] Example 1: Preparation of raw materials

[0067] 1.1 Preparation of CsYF4@Yb2O3 nanocrystals

[0068] 140 mg of EDTA was added to a 50 mL beaker, followed by 25 mL of ultrapure water and rapid stirring for 5 minutes. Then, 0.8 mL of Y(NO3)3 (0.6 mol / L) and 0.1 mL of Yb2O3 (0.6 mol / L) were added, and the mixture was rapidly stirred for 30 minutes. Subsequently, 2 mL of NH4F (0.8 mol / L) and 2 mL of CsF (0.8 mol / L) were added, and the mixture was stirred continuously for 30 minutes until a milky white solution was produced. The solution was transferred to a 200 °C autoclave and reacted for 24 hours. After cooling to room temperature, the mixture was washed three times alternately with ultrapure water and alcohol, and then dried at 70 °C for 2 hours to obtain the CsYF4@Yb2O3 nanocomposite material. The dried material was then ready for further use.

[0069] 1.2 Characterization of the properties of CsYF4@Yb2O3 composite material

[0070] Transmission electron microscopy and particle size distribution of CsYF4@Yb2O3 composite material were determined as follows: Figure 2 As shown, the photothermal temperature change is as follows Figure 3 As shown, the CsYF4@Yb2O3 composite material has the strongest heating capacity, which is superior to CsYF4 and Yb2O3.

[0071] 1.3 Adsorption of CsYF4@Yb2O3 with Antibody: A mixture of CsYF4@Yb2O3 composite material, estrone antibody, and bovine serum albumin was prepared, namely, a mixture of CsYF4@Yb2O3-mAb.

[0072] Take 1 mL of CsYF4@Yb2O3 into a centrifuge tube, add 4 μL of 0.2 mW / L K2CO3 solution to adjust the pH of the system, vortex to mix, then add 5 μL of 1 mg / mL estrone antibody, mix well, and incubate at room temperature with shaking for 45 min. After the reaction is complete, add 100 μL of BSA (m / m = 5%) for blocking for 1 h, centrifuge at 12000 r / min for 30 min, remove the supernatant, and then redissolve in 100 μL of buffer (20 mW / L Na3PO4, 5% BSA, 0.25% Tween-20, 10% sucrose) to obtain the CsYF4@Yb2O3-mAb mixture, and store at 4℃ for later use.

[0073] 1.4 Preparation of the solution for the detection zone (T zone)

[0074] Estrone-BSA was diluted to 0.6 mg / mL with 10 mM PBS solution at pH 7.4.

[0075] 1.5 Preparation of solutions for the quality control zone (Zone C)

[0076] The goat anti-mouse secondary antibody was diluted to 0.4 mg / mL with 10 mM PBS solution at pH 7.4.

[0077] Example 2: Preparation of test strips

[0078] Attach the NC membrane to the center of the PVC base plate. Overlap the sample pad and absorbent pad to the left and right ends of the NC membrane, respectively, so that they cover the NC membrane by about 2 mm. Cut the assembled card into strips with a width of 3 mm. Draw the detection line (T zone) and the control line (C zone) on the NC membrane, with a 4 mm interval between the two lines, to obtain the blank test strip. Add 0.5 μL of T zone solution and 0.5 μL of C zone solution to T zone and C zone respectively. Place the test strip after spotting in an oven and dry it at 37°C for 60 min. Store it in a vacuum bag for later use.

[0079] Example 3: Preparation of test strips containing binding pads

[0080] Test strips according to Figure 1The binding method consists of a sample pad, a nitrocellulose membrane (NC), a conjugation pad, and a PVC base plate. The NC membrane is adhered to the center of the PVC base plate, and a detection line (T zone) and a control line (C zone) are drawn on the NC membrane, with a 4mm gap between the two lines. Then, the right end of the conjugation pad overlaps the left end of the NC membrane, covering it by about 2mm. The sample pad overlaps the left end of the conjugation pad, covering it by about 2mm. The absorbent pad overlaps the right end of the NC membrane, covering it by about 2mm. The assembled test strip is cut into 3mm wide strips. A mixture of 10μL CsYF4@Yb2O3 composite material, estrone antibody, and bovine serum albumin (CsYF4@Yb2O3-mAb mixture) is fixed on the conjugation pad. 0.5μL of the T zone solution and 0.5μL of the C zone solution are added to the T zone and C zone respectively. The sampled test strips are placed in an oven and dried at 37℃ for 60min, then stored in a vacuum bag for later use.

[0081] Example 4: Working Curve Plotting

[0082] Prepare 10 mL of 1 mg / mL estrone standard solution using acetonitrile, and dilute to a concentration of 10 mM PBS. -2 pg / mL, 10 - 1 pg / mL, 10 0 pg / mL, 10 1 pg / mL, 10 2 pg / mL, 10 3 pg / mL, 10 4 pg / mL, 10 5 pg / mL, prepared as the test solution. Mix 80 μL of the test solution with 10 μL of CsYF4@Yb2O3-mAb and 10 μL of running buffer (10 mM PBS solution containing 5% sucrose, 1% BSA, 1% Tween-20, pH 7.4) in a centrifuge tube for 10 min. Then insert the test strip into the centrifuge tube, remove the test strip after 10 min, and allow it to dry. Finally, use a near-infrared LED (power 1.36 W / cm²) to test. 2 Irradiation for 3 minutes was performed, and temperature changes were monitored using a mobile phone and infrared thermal imaging accessories. The results of the photothermal mode are as follows: Figure 4 As shown; the working curve is y = 2.681x + 0.517(R). 2 =0.9891).

[0083] The results showed that under photothermal mode, the negative T region had the highest temperature and the estrone concentration was 10. 5 The temperature in region T drops to its lowest point at a concentration of pg / mL; this concentration is used as the detection limit for the photothermal mode. Therefore, the detection limit of the constructed dual-mode test strip can reach 10. -1 pg / mL.

[0084] Example 5: Detection of estrone

[0085] The specificity of the CsYF4@Yb2O3 complex photothermal quantitative test strip for estrone was verified, including the following steps:

[0086] 1. Preparation of test paper materials

[0087] Same as Example 1.

[0088] 2. Preparation of test strips

[0089] Same as Example 3.

[0090] 3. Drawing working curves

[0091] Same as Example 4.

[0092] 4. Specificity

[0093] Prepare 10 mL of 1 mg / mL standard solutions of estrone, estradiol, estriol, diethylstilbestrol, and hexanestilbestrol using acetonitrile. Dilute these solutions with 10 mM PBS to a concentration of 120 ng / mL and use them as test solutions.

[0094] 5. Sample testing

[0095] Mix 80 μL of the test solution with 10 μL of CsYF4@Yb2O3-mAb and 10 μL of running buffer (10 mM PBS solution containing 5% sucrose, 1% BSA, 1% Tween-20, pH 7.4) in a centrifuge tube for 10 min. Then insert the test strip into the centrifuge tube and wait for the test strip to dry. Finally, use a near-infrared LED (power 1.36 W / cm²) to measure the mixture. 2 Irradiation for 3 minutes was performed, and temperature changes were monitored using a mobile phone and infrared thermal imaging accessories. The results of the photothermal mode are shown as follows: Figure 5 As shown in the figure, compared with the blank, estradiol, estriol, diethylstilbestrol, and hexanestilbestrol have very weak effects on the T-zone temperature of the test strip, while estrone has a very significant effect on the T-zone temperature of the test strip. This indicates that the test strip has a weak response to the four substances, meaning that the test strip has good specificity.

[0096] As can be seen from the above embodiments, the CsYF4@Yb2O3 composite material provided in this application, when used in the preparation of photothermal test strips, does not require alteration of the conventional structure of the test strip. It can be used as a photothermal signal probe, either independently of the aforementioned photothermal test strip form for convenient storage, or fixed to the conjugate pad of the test strip for easy portability. The detection method of this invention, which includes a photothermal test strip for detecting estrone, is based on the plasma resonance effect. It uses the high photothermal conversion efficiency and small size of the CsYF4@Yb2O3 composite material as a T-region fixed photothermal signal probe, excited by a near-infrared laser source. Combined with a smart terminal and infrared thermal imaging accessories, it achieves photothermal signal acquisition, effectively removing sample liquid base color and test strip fluorescence background interference, thereby improving the signal-to-noise ratio. The detection method has a lower detection limit, a wider detection range, and better specificity, exhibiting higher sensitivity than other photothermal test strips.

[0097] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A test strip for detecting estrone, characterized in that, The test strip includes a photothermal signal probe and a test strip body; The photothermal signal probe is prepared by modifying a CsYF4@Yb2O3 composite material with an estrone monoclonal or polyclonal antibody, and is used in a form independent of the main structure of the photothermal test strip or in a form dried on the conjugate pad. The main body of the test strip includes a PVC base plate, a sample pad, a nitrocellulose membrane (NC membrane), and an absorbent pad.

2. The test strip for detecting estrone according to claim 1, characterized in that, The preparation method of the CsYF4@Yb2O3 composite material includes the following steps: (1) Mix Y(NO3)3 and Yb2O3 in an aqueous solution of ethylenediaminetetraacetic acid, and while stirring, add NH4F solution and CsF solution in sequence, and continue stirring until a milky white solution is produced; (2) The milky white solution was placed at high temperature to react. After the reaction was completed, it was cooled to room temperature, washed and dried to obtain the CsYF4@Yb2O3 composite material.

3. The test strip for detecting estrone according to claim 2, characterized in that, In step (1), one or more of the following conditions must be met: The molar ratio of Y(NO3)3 to Yb2O3 is 1:10-10:1; The concentration of the aqueous solution of ethylenediaminetetraacetic acid is 5-7 mg / mL; The concentration of the NH4F solution is 0.8-1.2 mol / L; The concentration of CsF solution is 0.8-1.2 mol / L; The ratio of Y(NO3)3 to NH4F and CsF is 1:5-5:1; Stirring should be performed at room temperature for 5-30 minutes. In step (2), one or more of the following conditions must be met: The high-temperature reaction is carried out at a temperature of 160-250℃ for 12-36 hours. The cleaning process involves alternating between ultrapure water and alcohol 2-3 times. Dry at 50-80°C for 1-4 hours.

4. A photothermal signal probe prepared from the CsYF4@Yb2O3 composite material as described in claim 1, characterized in that, The mixture contains CsYF4@Yb2O3 composite material, estrone antibody, and bovine serum albumin; the CsYF4@Yb2O3 composite material is mixed with estrone antibody and bovine serum albumin to obtain CsYF4@Yb2O3-mAb mixture.

5. A test strip containing the photothermal signal probe of claim 4, characterized in that, The test strip includes a photothermal signal probe and a test strip body; The main body of the test strip comprises: a sample pad, a nitrocellulose membrane (NC membrane), and an absorbent pad, which are sequentially and overlappingly pasted from top to bottom on a PVC base plate in a horizontal direction; wherein, the nitrocellulose membrane is used to separate and detect analytes from other substances in the sample, the sample pad is used for sample loading, the absorbent pad is used to absorb excess liquid, and the PVC base plate provides physical support for the test strip; the nitrocellulose membrane includes a detection zone (T zone) and a control zone (C zone); wherein, the T zone is immobilized with estrone antigen, i.e., the analyte-protein conjugate; the C zone is immobilized with a secondary antibody, which is a secondary antibody against the primary antibody, i.e., an anti-primary antibody; The photothermal signal probe can be used independently of the main structure of the photothermal test strip, or the photothermal signal probe can be dried on the conjugate pad and the conjugate pad can be inserted between the sample pad and the NC membrane.

6. The test strip according to claim 5, characterized in that, Estrone antibodies, or primary antibodies, can be derived from at least one of the following sources: mice, rats, and rabbits.

7. The test strip according to claim 5, characterized in that, The secondary antibody includes at least one of goat anti-mouse secondary antibody, rabbit anti-mouse secondary antibody, goat anti-rabbit secondary antibody, and donkey anti-rabbit secondary antibody.

8. An application of the test strip of claim 5 for non-disease diagnosis and treatment purposes, characterized in that, Used for detecting estrone; the photothermal temperature of the detection area is negatively correlated with the estrone content to be measured, and the color intensity is negatively correlated with the estrone content in the sample, specifically: When the sample does not contain estrone, the T region appears purple and the temperature is high. When the sample contains estrone, the T region appears light purple or even disappears, and the temperature decreases. The quality control area, which serves as a reference for verifying the validity of the test strip results, always appears purple.

9. The application according to claim 8, characterized in that, The method for detecting estrone using test strips includes the following steps: When the photothermal signal probe is used independently of the main structure of the photothermal test strip, it specifically includes: Mix the sample to be tested with CsYF4@Yb2O3-mAb solution in the running buffer for 3-10 min, and then place the test strip in the buffer. After 15-30 min, read the colorimetric results and perform semi-quantitative analysis. Obtain a photograph of the colorimetric results, perform grayscale analysis using image processing software, and then perform quantitative analysis. When the photothermal signal probe is dried on the conjugate pad and the conjugate pad is inserted between the sample pad and the NC membrane in the main body structure of the test strip, the specific steps include: The sample to be tested is mixed with the running buffer solution and placed into the test strip. After 20-40 minutes, the colorimetric results are read and a colorimetric result photograph is obtained for semi-quantitative analysis. Grayscale analysis is performed using image processing software for quantitative analysis. After the test strip is dried, it is placed under a near-infrared LED light source for excitation. The temperature result is obtained using a thermal imaging or temperature measuring device and a smart display terminal. The thermal imaging or temperature measuring device includes at least one of a mobile phone infrared thermal imaging analysis accessory, an infrared thermal imager, and a temperature gun. The smart display terminal includes at least one of a computer and a smartphone. The thermal imaging device acquires photothermal imaging photos and outputs and displays them through the connected smart display terminal.

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