CN112782099A - Preparation method of cellulose silicon-based cascade double-ring resonant cavity chip for detecting PCA3 - Google Patents

Abstract

The invention discloses a preparation method of a cellulose silicon-based cascade bicyclic resonant cavity chip for detecting PCA3, belonging to the technical field of cascade bicyclic resonant cavity sensing. The fixing amount of the PCA3 gene probe on the surface of the sensing ring is increased by modifying the cellulose nano film on the surface of the sensing ring, the number of chips combined with the PCA3 is increased by utilizing the specific combination property of the PCA3 gene probe and the PCA3, the response signal of the silicon-based cascade double-ring resonant cavity sensor to the PCA3 is greatly improved, and the unmarked, high-sensitivity and high-selectivity detection of the PCA3 is realized. The functional chip for detecting PCA3 reduces the detection cost, and is expected to be widely applied to diagnosis and treatment of prostate cancer.

Description

Preparation method of cellulose silicon-based cascade double-ring resonant cavity chip for detecting PCA3

Technical Field

The invention relates to the technical field of cascaded double-ring resonant cavity sensing, in particular to a preparation method of a cellulose silicon-based cascaded double-ring resonant cavity chip for detecting PCA 3.

Background

Prostate cancer is one of common tumors threatening the health of men, and the incidence rate of prostate cancer in China is always on the rise in recent years. Prostate cancer is said to be a "silent killer," not easily detectable at an early stage, with about 2/3 cancer patients having advanced to an advanced stage when diagnosed, and overall survival and quality of life being severely affected. The data show that 65-75% of prostate cancer patients have bone metastasis, bone related events such as bone pain, pathological fracture, limb movement disorder, spinal cord compression, hypercalcemia and the like, and even lower limb paralysis. Meanwhile, patients with advanced prostate cancer also have symptoms of low mood, deep digestion, insomnia, depression, general weakness and the like.

Early screening not only aids in the early detection of prostate cancer, but also helps to reduce prostate cancer mortality and improve life quality during life. Blood drawing for Prostate Specific Antigen (PSA) is the best method for diagnosing early stage suspected prostate cancer. However, PSA has prostate tissue specificity but no tumor specificity, and is also increased in some benign prostate diseases, PSA examination has the disadvantages of over-diagnosis of low-risk prostate cancer and under-diagnosis of high-grade prostate cancer, and such needle biopsy is invasive, causes great pain to patients, is prone to over-puncture, and may cause complications such as hematuria and rectal bleeding.

The PCA3 molecular detection can effectively solve the dilemma faced by the clinical application for prostate cancer screening. Prostate cancer gene 3 (PCA 3) is a non-coding RNA highly expressed in prostate cancer tissue, not only organ (prostate) specific, but also tumor specific, and PCA3 is not affected by age, prostate volume or other prostate diseases (prostatitis). PCA3 is specifically and highly expressed in prostate cancer cells, and is one of the tumor markers with high specificity for prostate cancer. The PCA3 gene expression quantity in urine cells is detected, so that early screening of the prostate cancer can be realized, over-puncture biopsy can be avoided, and pain of a patient can be relieved. Therefore, the detection of PCA3 is of great significance for early diagnosis and timely treatment of prostate cancer.

Currently, real-time fluorescent quantitative RT-PCR is often used for detection of PCA3, e.g., (hainan medicine) 2019, 30 (23): 3044 application of quantitative detection of mRNA density of PCA3 in prostate cancer diagnosis in the gray area of PSA (prostate cancer), published in the treatise on Chinese tumor prevention and treatment journal 2018, 25(05):329 published "review of the diagnostic value of prostate cancer in the gray area of PSA using the combined assay scores of serum PHI and urine PCA 3" by Zhang Zheng and Liu Gui Li et al, "Clinical Chemistry & Laboratory Medicine" 2016, 54(3):483 to Riane J.Hendriks, Siebren Dijkstra et al, comprehensive analysis of state specific biological operators PCA3and ERG in book urine, urinary segments and exosomes, Experimental & Molecular Pathology 2010,89(1):58 issued to Zhihua Tao, Mo Shen et al, "PCA 3 gene expression in program cancer tissue in a Chinese position: quantitative by real-time FQ-RT-PCR based on exon 3of PCA3, the content of biomarkers in urine was determined by RT-qPCR.

Although the RT-PCR fluorescence quantitative method has high sensitivity, the method has some insurmountable limitations such as the need of fluorescence labeling, professional technicians for operation, harsh experimental conditions, long turnaround time and the like, which seriously limits the application of the method in low-resource environment. Furthermore, since the thermocycling amplification step risks falsely amplifying non-specific contaminants, false positive results may occur and the sensitivity and specificity of the test is not ideal. Therefore, in order to provide a more accurate early diagnosis of prostate cancer, it is necessary to find new methods for the direct quantitative detection of PCA3 without the need for fluorescent labels.

The silicon-based cascaded double-ring resonant cavity sensor has very high refractive index sensitivity due to the vernier amplification effect between the reference ring and the sensing ring, and can realize unmarked high-sensitivity detection on an object to be detected. However, since the cascaded double ring resonator sensor will show the same spectrum signal for the same refractive index material, the selective detection of the PCA3 can not be realized. If the method of directly reacting and connecting the PCA3 gene probe with the hydroxyl functional group on the surface of the resonant cavity is adopted, the quantity of the immobilized PCA3 gene probe is usually too small, so that the signal change of the cascade bicyclic resonant cavity sensor can not be observed or the observed signal change is very weak when the PCA3 is detected. Therefore, in order to perform more accurate and high-sensitivity detection and diagnosis on the PCA3 by using the cascaded double-ring resonator sensor, a preparation method of a cascaded double-ring resonator chip with a functionalized PCA3 probe with excellent performance needs to be found.

Disclosure of Invention

Aiming at the prior art, the invention aims to provide a preparation method of a cellulose silicon-based cascade double-ring resonant cavity chip for detecting PCA 3.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect of the present invention, a cellulose silicon-based cascaded dual-ring resonator chip for detecting PCA3 is provided, including: a first waveguide, a second waveguide, and a third waveguide; a reference ring is arranged between the first waveguide and the second waveguide and is respectively coupled with the first waveguide and the second waveguide; a sensing ring is arranged between the second waveguide and the third waveguide and is respectively coupled with the second waveguide and the third waveguide; the method comprises the following steps that incident light enters a first waveguide to be coupled with a reference ring, light led out from the reference ring is further coupled with a second waveguide, part of the light coupled with the reference ring and the second waveguide leaks from a mid end of the second waveguide, part of the light is further coupled with a sensing ring, and the light led out from the sensing ring is further coupled with a third waveguide and then is output from a pass end;

and the surface of the sensing ring is sequentially modified and fixed with a silane coupling agent, a cellulose film and a PCA3 gene probe.

Preferably, the silane coupling agent is 3-aminopropyltriethoxysilane, 3- (2, 3-glycidoxy) propyltrimethoxysilane or 3- (2, 3-glycidoxy) propyltriethoxysilane.

Preferably, the cellulose film is made of cellulose or cellulose derivatives or cellulose copolymers or blends doped with other nanoparticles; more preferably, the cellulose derivative is one or more of carboxylated cellulose, polymeric cellulose, hydroxypropyl methyl cellulose and hydroxyethyl cellulose.

Preferably, the PCA3 gene probe is designed by using 4 exons of PCA3 as templates.

Preferably, the sequence of the PCA3 gene probe includes but is not limited to that shown in SEQ ID NO.1, SEQ ID NO.2 or SEQ ID NO.3, and specifically is as follows:

NH₂-(CH₂)₆-AAAAATTGTTCAAAGACCCTTCGTGTT；(SEQ ID NO.1)

NH₂-(CH₂)₆-AAAAACTGCTGACTTTACCATCTGAGGCCAC；(SEQ ID NO.2)

NH₂-(CH₂)₆-AAAAATCCTGGTCTCCCTCGGCTGCA；(SEQ ID NO.3)

in a second aspect of the present invention, a method for preparing the cellulose silicon-based cascaded dual-ring resonator chip for detecting PCA3 is provided, which includes the following steps;

(1) preprocessing a silicon-based cascaded double-ring resonant cavity;

(2) modifying a silane coupling agent on the surface of a pretreated sensing ring of the silicon-based cascaded bicyclic resonant cavity;

(3) further modifying cellulose on the surface of the sensing ring modified by the silane coupling agent;

(4) the PCA3 gene probe is further modified on the cellulose surface of the sensing ring.

Preferably, in the step (3), the cellulose modified on the surface of the sensing ring is immobilized by covalent reaction between the cellulose and a silane coupling agent on the surface of the sensing ring.

Preferably, in the step (4), the PCA3 gene probe is immobilized on the surface of the cellulose film through covalent reaction of the PCA3 gene probe and cellulose.

In a third aspect of the invention, the application of the silicon-based cascade bicyclic resonant cavity chip modified by the cellulose film with the functionalized PCA3 gene probe in preparing a PCA3 diagnosis and/or detection product is provided.

The fourth aspect of the invention provides a preparation method of a cellulose silicon-based cascade double-ring resonator chip for detecting PCA3, which comprises the following steps:

and contacting a sensing ring of the silicon-based cascade double-ring resonant cavity chip modified by the cellulose film functionalized by the PCA3 gene probe with liquid to be detected, and qualitatively or quantitatively detecting the PCA3 in the liquid to be detected according to a wavelength change signal or an optical power intensity change signal.

The invention has the beneficial effects that:

(1) when the cellulose silicon-based cascade bicyclic resonant cavity chip for detecting PCA3 is used for detecting PCA3, compared with a common RT-PCR fluorescence quantitative method, the preparation method of the cellulose silicon-based cascade bicyclic resonant cavity chip does not need fluorescence labeling and amplification, does not need harsh experimental conditions and longer turnover time, greatly simplifies operation steps, saves detection time and reduces detection cost.

(2) According to the preparation method of the cellulose silicon-based cascade double-ring resonant cavity chip for detecting PCA3, when the chip is used for detecting PCA3, noninvasive, rapid and non-radiative detection can be achieved, and pain of a patient caused by puncture blood sampling is avoided.

(3) According to the preparation method of the cellulose silicon-based cascade double-ring resonant cavity chip for detecting PCA3, the adopted cellulose is polysaccharide which is most widely distributed and contained in nature, the raw materials are easy to obtain, and the detection cost is effectively reduced.

(4) According to the preparation method of the cellulose silicon-based cascade double-ring resonant cavity chip for detecting PCA3, the adopted cellulose is tasteless, odorless, nontoxic, harmless and free of environmental pollution, and the operation process is safer and more environment-friendly.

(5) According to the preparation method of the cellulose silicon-based cascade double-ring resonant cavity chip for detecting PCA3, the adopted cellulose is insoluble in water, dilute alkali solution and common organic solvent at normal temperature and is very stable at normal temperature, and the formed cellulose film can better protect the substrate silicon and the reference ring resonant cavity from being corroded by liquid in the experimental process and can better ensure the stability of signals.

(6) According to the preparation method of the cellulose silicon-based cascade double-ring resonator chip for detecting PCA3, the adopted cellulose molecules contain a large number of hydroxyl functional groups, so that more groups can be used for further modifying the PCA3 gene probes, the number of the fixed PCA3 gene probes can be obviously increased, the signal intensity of the cascade double-ring resonator for detecting the PCA3 can be effectively improved, and the sensitivity and the detection range of the PCA3 can be improved.

In conclusion, the preparation method of the cellulose silicon-based cascade double-ring resonator chip for detecting PCA3 has the advantages of low cost, no mark and high sensitivity when the chip is used for detecting PCA3, and is expected to be widely applied to prevention and treatment of PCA 3.

Drawings

FIG. 1: the invention discloses a cross-sectional schematic diagram of a silicon-based cascaded double-ring resonant cavity; in the figure, 1-incident light, 2-first waveguide, 3-reference ring, 4-second waveguide, 5-mid end of second waveguide, 6-sensing ring, 7-third waveguide, 8-drop end of third waveguide.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

As described in the background section, the detection of PCA3 is important for early diagnosis and timely treatment of prostate cancer. PCA3 localized to chromosome 9, was approximately 25kb in length, and contained 3 introns and 4 exons, and studies showed that PCA3 is a non-coding RNA gene with very few protein products and is therefore more targeted for gene testing of PCA 3.

Biosensors based on optical ring resonators are currently receiving a lot of attention. In the ring resonant cavity, light waves are continuously and circularly transmitted around the micro-ring, and the evanescent waves passing through the surface of the waveguide contact with a tested sample to act. Different from the traditional planar optical waveguide sensor, in the annular resonant cavity sensor, because the optical wave is continuously transmitted around the ring, the action length of the optical wave and the measured sample is not the physical actual length of the resonant cavity any more, but is related to the quality factor Q of the resonant cavity, therefore, the annular resonant cavity can realize great sensing sensitivity with a very small physical size, not only low cost and miniaturization are realized, but also expensive medicines are saved to a great extent in the biological sensing process.

The cascade dicyclic resonant cavity waveguide sensor consists of two ring resonant cavities with different radiuses, including sensing ring and reference ring, where the sensing ring has no spin coating upper cladding layer to contact directly with the liquid to be measured and the reference ring is covered with one upper cladding layer. When the concentration of the liquid to be detected changes, the mode characteristic of light transmitted in the waveguide is influenced, the change of resonance wavelength or the change of power intensity is further influenced, and the parameter change of the liquid to be detected can be obtained by analyzing the change of the resonance spectrum. The cascaded double-ring resonant cavity sensor has a unique double-ring structure, and the sensor ring and the reference ring form a vernier amplification effect similar to a vernier caliper, so that the sensitivity of the device is greatly improved compared with that of the traditional single-ring sensor.

At present, no report of using a cascade bicyclic resonant cavity waveguide sensor to detect PCA3 exists, and based on the report, the invention carries out deep research and provides a preparation method of a cellulose silicon-based cascade bicyclic resonant cavity chip for detecting PCA 3.

In one embodiment of the invention, the silicon-based cascaded double-ring resonant cavity waveguide chip modified by the cellulose film comprises: the optical waveguide comprises a first waveguide 2, a reference ring 3, a second waveguide 4, a sensing ring 6 and a third waveguide 7, wherein incident light 1 enters the first waveguide 2 to be coupled with the reference ring 3, light guided out from the reference ring 3 is further coupled with the second waveguide 4, part of the light coupled by the reference ring 3and the second waveguide 4 leaks from a mid end 5 of the second waveguide, part of the light is further coupled with the sensing ring 6, the light guided out from the sensing ring 6 is further coupled with the third waveguide 7 and then is output from a pass end 8 (figure 1), by sequentially modifying and fixing a silane coupling agent, a cellulose film and a PCA3 gene probe on the surface of a sensing ring 6 in a silicon-based cascade double-ring resonant cavity chip, the modified cellulose film is used for increasing the fixed quantity of the PCA3 gene probe, and the high-sensitivity selective detection of the PCA3 is realized by utilizing the signal change caused by the combination of the PCA3and the PCA3 gene probe and the vernier amplification effect between the sensing ring and the reference ring.

The silicon-based cascade double rings of the invention refer to a reference ring 3and a sensing ring 6, and a micro-ring resonant cavity used for modifying a silane coupling agent, a cellulose film and a PCA3 gene probe is the sensing ring 6 instead of the reference ring 3.

The detection of PCA3 as described herein is accomplished by sensing the change in refractive index of sensing ring 6.

The silane coupling agent used for modifying the surface of the sensing ring is aminosilane or epoxy silane, and specifically can be 3-aminopropyltriethoxysilane or 3- (2, 3-glycidoxy) propyltrimethoxysilane or 3- (2, 3-glycidoxy) propyltriethoxysilane.

The cellulose film is fixed on the surface of the sensing ring 6 by covalent reaction of cellulose and epoxy silane or amino silane on the surface of the sensing ring 6.

The cellulose used in the preparation of the cellulose film is cellulose, and cellulose derivatives such as carboxylated cellulose, polymerized cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose and the like.

The prepared cellulose film may further comprise a cellulose copolymer or blend doped with other nanoparticles.

The PCA3 probe is immobilized on the surface of a cellulose film through the covalent reaction of the PCA3 probe and cellulose.

The PCA3 probe is designed by using 4 exons of PCA3 as templates.

The process for modifying the PCA3 probe on the surface of the sensing ring 6 comprises the following steps:

preprocessing a silicon-based cascaded double-ring resonant cavity;

modifying epoxy silane or amino silane on the surface of the sensing ring 6;

thirdly, further modifying cellulose on the surface of the sensing ring 6 modified by amino silane or epoxy silane;

and fourthly, further modifying the PCA3 probe on the cellulose surface of the sensing ring 6.

The signal adopted when the chip is used for detecting the PCA3 content in the sample is a wavelength change signal or a power intensity change signal.

The PCA3 probe has the performance of specific binding with PCA3, and the selective detection of the PCA3 is realized by the signal change caused by the specific binding of the silicon-based cascade bicyclic resonant cavity sensor.

The process of modifying the PCA3 probe on the surface of the sensing ring 6 can be specifically as follows: pretreating the silicon-based cascaded double-ring resonant cavity, and dripping a solution containing a silane coupling agent on the surface of a sensing ring of the pretreated silicon-based cascaded double-ring resonant cavity for 30-60 min; then, the sensing ring is put into a solution containing cellulose, the reaction is carried out for 4 to 24 hours at the temperature of between 80 and 100 ℃, and a cellulose film is further modified on the surface of the sensing ring modified by the silane coupling agent; then, the sensing ring is put into a solution which is filled with nitrogen and contains succinic anhydride, and the reaction is carried out for 24 hours at room temperature, or triethylamine is dripped into the solution and then the reaction is carried out for 6 hours at 110 ℃; and then transferring the sensing ring into EDC/NHS solution, standing for 30-90min, then transferring into solution containing PCA3 gene probe, and further modifying PCA3 gene probe on the surface of the cellulose film.

Wherein the pretreatment specifically comprises the following steps: immersing the silicon-based cascade bicyclic resonant cavity in a piranha solution for treatment for 30min at 80 ℃, cleaning with ultrapure water, and then immersing in ammonia water: hydrogen peroxide: treating in a solution with a water volume ratio of 1:1:5 for 1h, and cleaning with ultrapure water.

The solution containing the silane coupling agent includes, but is not limited to: a toluene solution containing 2% 3-aminopropyltriethoxy silicon, an anhydrous toluene solution containing 1% 3- (2, 3-glycidoxy) propyltrimethoxy silane, or an anhydrous ethanol solution containing 2.5% 3-aminopropyltriethoxy silane.

The cellulose-containing solution includes, but is not limited to: an aqueous solution of carboxymethyl cellulose, a DMSO solution containing LiCl and cellulose, or a DMF solution containing cellulose.

In the solution containing the succinic anhydride, the concentration of the succinic anhydride is 2-245 mg/ml.

In order to make the technical solutions of the present application more clearly understood by those skilled in the art, the technical solutions of the present application will be described in detail below with reference to specific embodiments.

Example 1

The silicon-based cascade bicyclic resonant cavity is immersed in a piranha solution (98% sulfuric acid: 30% hydrogen peroxide: 7:3) for treatment at 80 ℃ for 30min, cleaned with ultrapure water, and then immersed in a solution prepared by mixing ammonia water: hydrogen peroxide: treating in a solution with a water volume ratio of 1:1:5 for 1h, and cleaning with ultrapure water. And (3) dropwise adding a 2% toluene solution of 3-aminopropyl triethoxy silicon on the sensor ring of the processed silicon-based cascade bicyclic resonant cavity for processing for 1h, and then processing for 30min at 120 ℃. Then, 5ml of an aqueous solution containing 0.271g of carboxymethyl cellulose was placed in the sensor ring and reacted at 90 ℃ for 15 hours. The sensor ring was then placed in 5ml of methanol containing 100mg succinic anhydride and reacted at room temperature for 24 h. The sensor loop was then transferred to a freshly prepared solution of EDC/NHS (0.04M: 0.01M) for 1h and subsequently to a solution containing 10. mu.M of PCA3 probe NH₂-(CH₂)₆And (3) carrying out refrigerator reaction at 4 ℃ in PBS (phosphate buffer solution) of-AAAAATTGTTCAAAGACCCTTCGTGTT overnight to prepare the cellulose silicon-based cascade bicyclic resonant cavity chip for detecting PCA 3.

Example 2

The silicon-based cascade bicyclic resonant cavity is immersed in a piranha solution (98% sulfuric acid: 30% hydrogen peroxide: 7:3) for treatment at 80 ℃ for 30min, cleaned with ultrapure water, and then immersed in a solution prepared by mixing ammonia water: hydrogen peroxide: treating in a solution with a water volume ratio of 1:1:5 for 1h, and cleaning with ultrapure water. Dropping the liquid-treated sensing ring surface of the silicon-based cascade bicyclic resonant cavity into an anhydrous toluene solution containing 1% of 3- (2, 3-epoxypropoxy) propyl trimethoxy silaneAfter drying at 110 ℃ for 1h, the sensor ring was placed in 5ml of DMSO solution containing 0.01g LiCl and 0.5g cellulose and reacted at 80 ℃ for 24 h. The sensor ring was then placed in 9ml of a solution of tetrahydrofuran containing 25mg succinic anhydride and purged with nitrogen and allowed to react overnight at room temperature for 24 h. The sensor loop was then transferred to a freshly prepared 0.02MEDC/0.01MNHS solution for 1h and subsequently transferred to 10. mu.M of PCA3 probe NH₂-(CH₂)₆And (3) carrying out refrigerator reaction at 4 ℃ in PBS (phosphate buffer solution) of-AAAAACTGCTGACTTTACCATCTGAGGCCAC overnight to prepare the cellulose silicon-based cascade bicyclic resonant cavity chip for detecting PCA 3.

Example 3

The silicon-based cascade bicyclic resonant cavity is immersed in a piranha solution (98% sulfuric acid: 30% hydrogen peroxide: 7:3) for treatment at 80 ℃ for 30min, cleaned with ultrapure water, and then immersed in a solution prepared by mixing ammonia water: hydrogen peroxide: treating in a solution with a water volume ratio of 1:1:5 for 1h, and cleaning with ultrapure water. Then, 2.5 percent of 3-aminopropyltriethoxysilane absolute ethyl alcohol solution is dripped on a sensing ring of the silicon-based cascade bicyclic resonant cavity for processing for 1 hour, and then the sensing ring is put into 6ml of DMF solution containing 200mg of cellulose for reaction for 4 hours at 100 ℃. The sensor ring was then placed in 5ml of acetone solution containing 1.201g succinic anhydride and purged with nitrogen, and several drops of triethylamine were added dropwise and reacted at 110 ℃ for 6 hours. The sensor loop was then transferred to a freshly prepared 0.2MEDC/0.05MNHS solution for 1h and subsequently to 10. mu.M of PCA3 probe NH₂-(CH₂)₆And (3) carrying out refrigerator reaction at 4 ℃ in PBS (phosphate buffer solution) of-AAAAATCCTGGTCTCCCTCGGCTG CA overnight to prepare the cellulose silicon-based cascade bicyclic resonant cavity chip for detecting PCA 3.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

SEQUENCE LISTING

<110> Ji south China medical science and technology development Co., Ltd

<120> preparation method of cellulose silicon-based cascade double-ring resonant cavity chip for detecting PCA3

<130> 2020

<160> 3

<170> PatentIn version 3.5

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<212> DNA

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aaaaactgct gactttacca tctgaggcca c 31

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<213> Artificial sequence

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Claims (10)

1. A preparation method of a cellulose silicon-based cascaded double-ring resonant cavity chip for detecting PCA3 is characterized in that the silicon-based cascaded double-ring resonant cavity chip comprises the following steps: a first waveguide, a second waveguide, and a third waveguide; a reference ring is arranged between the first waveguide and the second waveguide and is respectively coupled with the first waveguide and the second waveguide; a sensing ring is arranged between the second waveguide and the third waveguide and is respectively coupled with the second waveguide and the third waveguide; the method comprises the following steps that incident light enters a first waveguide to be coupled with a reference ring, light led out from the reference ring is further coupled with a second waveguide, part of the light coupled with the reference ring and the second waveguide leaks from a mid end of the second waveguide, part of the light is further coupled with a sensing ring, and the light led out from the sensing ring is further coupled with a third waveguide and then is output from a pass end;

and the surface of the sensing ring is sequentially modified and fixed with a silane coupling agent, a cellulose film and a PCA3 gene probe.

2. The method for preparing the cellulose silicon-based cascade bicyclic resonator chip for detecting the PCA3 as claimed in claim 1, wherein the silane coupling agent is 3-aminopropyltriethoxysilane, 3- (2, 3-glycidoxy) propyltrimethoxysilane or 3- (2, 3-glycidoxy) propyltriethoxysilane.

3. The method for preparing the cellulose silicon-based cascade bicyclic resonator chip for detecting the PCA3 as claimed in claim 1, wherein the cellulose film is made of cellulose, cellulose derivatives or cellulose copolymer or blend doped with other nanoparticles.

4. The method for preparing the cellulose silicon-based cascade bicyclic resonator chip for detecting the PCA3 as claimed in claim 1, wherein the cellulose derivative is one or more of carboxylated cellulose, polymerized cellulose, hydroxypropyl methylcellulose and hydroxyethyl cellulose.

5. The method for preparing the cellulose silicon-based cascade bicyclic resonator chip for detecting the PCA3 as claimed in claim 1, wherein the PCA3 gene probe is designed by taking 4 exons of PCA3 as a template.

6. The method for preparing the cellulose silicon-based cascade bicyclic resonator chip for detecting the PCA3 as claimed in any one of claims 1-5, comprising the following steps;

(1) preprocessing a silicon-based cascaded double-ring resonant cavity;

(2) modifying a silane coupling agent on the surface of a pretreated sensing ring of the silicon-based cascaded bicyclic resonant cavity;

(3) further modifying cellulose on the surface of the sensing ring modified by the silane coupling agent;

(4) the PCA3 gene probe is further modified on the cellulose surface of the sensing ring.

7. The method for preparing the cellulose silicon-based cascade bicyclic resonator chip for detecting the PCA3 as claimed in claim 6, wherein in the step (3), the modification of the cellulose on the surface of the sensing ring is performed by covalent reaction between the cellulose and a silane coupling agent on the surface of the sensing ring.

8. The method for preparing the cellulose silicon-based cascade bicyclic resonator chip for detecting PCA 3of claim 6, wherein in step (4), the PCA3 gene probe is immobilized on the surface of the cellulose film through covalent reaction between the PCA3 gene probe and cellulose.

9. Use of the cellulose film-modified silicon-based cascaded bicyclic resonator chip of any one of claims 1-5 in the preparation of a PCA3 diagnostic and/or detection product.

10. A preparation method of a cellulose silicon-based cascade double-ring resonant cavity chip for detecting PCA3 is characterized by comprising the following steps:

contacting the sensing ring of the cellulose membrane silicon-based cascade double-ring resonant cavity chip with the PCA3 gene probe functionalized according to any one of claims 1-5 with liquid to be detected, and qualitatively or quantitatively detecting PCA3 in the liquid to be detected according to a wavelength change signal or an optical power intensity change signal.

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