阅读说明：本技术 基于熵驱动和杂交链反应的atp检测核酸传感器及其制备方法 (ATP detection nucleic acid sensor based on entropy driving and hybrid chain reaction and preparation method thereof ) 是由 邢超 王军 于 2020-06-29 设计创作，主要内容包括：本发明公开了基于熵驱动和杂交链反应的ATP检测核酸传感器及其制备方法。该核酸传感器包括5种探针,分别为H、F、A/B/S、H1和H2；本发明基于ATP核酸适配体构象转变,释放引发链,驱动熵驱动催化放大一级循环和杂交链式反应二级循环,最终通过荧光信号增强检测ATP分子。本核酸传感器具有反应迅速,灵敏度高,抗干扰能力强,反应条件温和等优点,能够弥补现有ATP检测方法的不足,实现ATP的快速准确的定量检测。(The invention discloses an ATP detection nucleic acid sensor based on entropy driving and hybrid chain reaction and a preparation method thereof. The nucleic acid sensor comprises 5 probes, namely H, F, A/B/S, H1 and H2; the invention is based on ATP aptamer conformation transition, releases initiation chain, drives entropy to drive catalytic amplification primary circulation and hybridization chain reaction secondary circulation, and finally detects ATP molecules through fluorescence signal enhancement. The nucleic acid sensor has the advantages of rapid reaction, high sensitivity, strong anti-interference capability, mild reaction conditions and the like, can make up for the defects of the existing ATP detection method, and realizes the rapid and accurate quantitative detection of ATP.)

1. An ATP-detecting nucleic acid sensor based on entropy-driven and hybrid strand reactions, characterized in that an upstream moisture-driving circuit comprises: reconstructing a probe H, pre-assembling a template probe A/B/S and a stimulating probe F; the downstream hybridization strand reaction circuit comprises: fluorescent dye-modified hairpin probes H1 and H2; the probe sequences are respectively as follows:

and (3) reconstructing a probe H: CAGGTTACCCTACGTCTCCATAGGGTAACCTGGGGGAGTATTGCGGAGGAAGGT, respectively;

pre-assembling a template probe A: TGGAGACGTAGGGTAACCTGAGGGCCG TAAGAGAGCTGTAGATTGGATCG, respectively;

pre-assembling a template probe B: CCACATACATCATATTCCCTCAGGTTACCCTACG, respectively;

pre-assembling a template probe S: GTCACTCGATCCAATCTACAGCTCTCTTACGG, respectively;

stimulation probe F: CGATCCAATCTACAGCTCTCTTACGGCCCTCATTC AATACCCTACG, respectively;

hairpin probe H1:

CGATCCAA(FAM)TCTACAGCAGATGTGTAGCTGTAGA(Dabcy 1)TTGGATCGAGTGAC；

hairpin probe H2: TACACATCTGCTGTAGATTGGATCGGTCACTCGATCCAATCTACAGC are provided.

2. A method for producing the nucleic acid sensor according to claim 1, comprising the steps of:

(1) dissolving the pre-assembled template probe A, B, S in Tris-HCl buffer solution, annealing for 8 minutes at 95 ℃ to ensure that the pre-assembled template probe A/B/S mixed solution is obtained after complete hybridization;

(2) pre-dissolving a hairpin probe H1 in a Tris-HCl buffer solution, and annealing at 95 ℃ for 8 minutes to obtain a stable H1 hairpin solution;

(3) pre-dissolving a hairpin probe H2 in a Tris-HCl buffer solution, and annealing at 95 ℃ for 8 minutes to obtain a stable H2 hairpin solution;

(4) pre-dissolving the reconstructed hairpin probe H in Tris-HCl buffer solution, and annealing at 95 ℃ for 8 minutes to obtain stable H hairpin solution;

(5) and (3) mixing the solutions prepared in the steps (1), (2), (3) and (4), and adding a stimulation probe F to obtain a sensing solution.

3. The method of claim 2, wherein the Tris-HCl buffer is composed of: 5mM Tris-HCl, 40 mM sodium chloride, pH 7.4; in the sensing solution, the final concentration of each probe was 200 nM.

4. Use of a nucleic acid sensor according to claim 1 in the preparation of a reagent for the detection of ATP, comprising the steps of:

(1) respectively adding ATP standard solutions with different concentrations and a sample to be detected into the sensing solution, and incubating for 1h at 37 ℃ in a constant-temperature metal bath;

(2) taking out each group of standard sample solution, and measuring the fluorescence value of each standard solution by using a fluorescence spectrometer; and obtaining an ATP concentration-fluorescence intensity standard curve;

(3) and calculating the concentration of ATP to be detected according to the fluorescence value of the sample to be detected.

5. The use of claim 4, wherein said fluorescence measurement of step (2) has an excitation wavelength of 488nm and an emission wavelength of 520 nm.

Technical Field

The invention belongs to the field of nucleic acid sensors, and particularly relates to an ATP detection nucleic acid sensor based on entropy driving and hybridization chain reaction and a preparation method thereof, in particular to an entropy driving circuit coupling hybridization chain reaction double amplification circuit based on nucleic acid aptamer regulation and a fluorescence biosensor for fluorescence detection of ATP.

Background

ATP has important reference significance in clinical medical diagnosis, the content of ATP is often related to the health degree of organisms, and the content of ATP in human serum is about 1 mu mol.L^-1When the content is abnormal, various diseases such asCardiovascular and cerebrovascular diseases, Parkinson's syndrome, ischemia, hypoglycemia, malignant tumors and the like, and ATP has wide clinical application, and can provide important auxiliary treatment for diseases such as cerebral hemorrhage sequelae, myocardial diseases, chronic hepatitis and the like. Therefore, the rapid, accurate, sensitive and specific ATP detection method is designed, which is not only beneficial to promoting the exploration of the mysteries of life on the molecular level, but also has important significance for the analysis of the latest drugs, clinical diagnosis, overcoming of a plurality of difficult and complicated diseases and the like, and has potential application value in the fields of environmental science, biology, medicine and the like.

Disclosure of Invention

The invention aims to provide an ATP detection nucleic acid sensor based on entropy driving and hybrid chain reaction and a preparation method thereof.

The following technical scheme is adopted for achieving the purpose:

the invention provides a nucleic acid sensor for detecting ATP cascade method, an upstream soil moisture driving circuit comprises: reconstructing a probe H, pre-assembling a template probe A/B/S and a stimulating probe F; the downstream hybridization strand reaction circuit comprises: fluorescent dye-modified hairpin probe H1 and hairpin probe H2. The probe sequences are respectively as follows:

and (3) reconstructing a probe H: CAGGTTACCCTACGTCTCCATAGGGTAACCTGGGGGAGTATTGCGGAGGAAGGT, respectively;

pre-assembling a template probe A: TGGAGACGTAGGGTAACCTGAGGGCCG TAAGAGAGCTGTAGATTGGATCG, respectively;

pre-assembling a template probe B: CCACATACATCATATTCCCTCAGGTTACCCTACG, respectively;

pre-assembling a template probe S: GTCACTCGATCCAATCTACAGCTCTCTTACGG, respectively;

stimulation probe F: CGATCCAATCTACAGCTCTCTTACGGCCCTCATTC AATACCCTACG, respectively;

hairpin probe H1:

CGATCCAA(FAM)TCTACAGCAGATGTGTAGCTGTAGA(Dabcy 1)TTGGATCGAGTGAC；

hairpin probe H2: TACACATCTGCTGTAGATTGGATCGGTCACTCGATCCAATCTACAGC, respectively;

the preparation method of the nucleic acid sensor comprises the following steps:

(1) dissolving the probe A, B, S in Tris-HCl buffer solution, annealing for 8 minutes at 95 ℃ to ensure that the probe is completely hybridized to obtain a preassembled template probe A/B/S mixed solution;

(2) pre-dissolving a hairpin probe H1 in a Tris-HCl buffer solution, and annealing at 95 ℃ for 8 minutes to obtain a stable H1 hairpin solution;

(3) pre-dissolving a hairpin probe H2 in a Tris-HCl buffer solution, and annealing at 95 ℃ for 8 minutes to obtain a stable H2 hairpin solution;

(4) pre-dissolving the reconstructed hairpin probe H in Tris-HCl buffer solution, and annealing at 95 ℃ for 8 minutes to obtain stable H hairpin solution;

(5) and (3) mixing the solutions prepared in the steps (1), (2), (3) and (4), and adding a stimulation probe F to obtain a sensing solution.

The Tris-HCl buffer contained the following final concentration components: 5mM Tris-HCl, 40 mM sodium chloride, pH 7.4; in the sensing solution, the final concentration of each probe was 200 nM.

The working principle of the sensor is shown in figure 1:

in the presence of ATP, the recognition probe H undergoes conformational transition, a hidden HI region of an H chain is exposed, and the 3-terminal base of HI is not hybridized with the 5-terminal base of S; and then HI continues to be complementarily matched with the subsequent structure of S, the base at the position is the original hybridization part of B and A, and A is replaced to form an HI/B/S hybrid. In this case, the S-middle part of the hybrid T/B/S has a 4-base unhybridized portion. F in the solution can be hybridized with the 4 bases, and is gradually hybridized with S towards two ends by taking the F as a fulcrum, HI and B originally hybridized with S are gradually replaced, so that HI and B are released, and the first cycle process is completed. The HI released into the solution can be continuously repeated in the first cycle process to continuously release B, so that signal amplification is realized.

The 5-terminus of B released into solution can hybridize with the 3' -end of hairpin H1, followed by gradual hybridization with the neck of H1, opening hairpin H1, forming a hybrid of B/H1. The 5 'end of H1 of the formed B/H1 hybrid can be continuously hybridized with the 3' end base of H2, so that the hairpin structure of H2 is opened, the B/H1/H2 hybrid is formed, the 5 'end of H2 can be continuously opened to the 3' end of H1, and the cycle is repeated to realize signal amplification. The stem position of H1 of the hairpin structure is modified with a fluorescent group FAM, and a complementary site thereof is modified with a quenching group Dabcy 1. While H1 maintains the hairpin structure, the fluorescence of FAM is quenched, with no fluorescent signal. When B opens H1 and further opens H2, and B/H1/H2/H1/H2/H1/H2/H1/H2 … … hybrid is formed, FAM is far away from Dabcy1, FAM fluorescence is recovered, and fluorescence signals are enhanced. The concentration of ATP in the solution can be measured by measuring the increase in the fluorescent signal.

Further, the application of the nucleic acid sensor to ATP ions comprises the following steps:

(1) respectively adding ATP standard solution and solution to be detected with different concentrations into the sensing solution, uniformly mixing, and incubating for 1 hour at 37 ℃ in a constant-temperature metal bath;

(2) taking out each group of mixed solution from the constant-temperature metal bath, and measuring the fluorescence value of each mixed solution;

(3) and (3) making a standard curve of the ATP concentration to the fluorescence value according to the fluorescence values of the ATP standard solutions with different concentrations, calculating a regression equation, and finally calculating the ATP concentration according to the fluorescence value of the sample to be detected.

And (3) the fluorescence value is measured, the excitation wavelength is 488nm, and the emission wavelength is 520 nm.

The ATP detection concentration is 0.1-2. mu.M.

The invention has the beneficial effects that: the invention provides a nucleic acid sensor for detecting ATP cascade signal amplification and a preparation method thereof, which realizes high specificity identification of ATP by utilizing ATP aptamer conformation transformation; the entropy is utilized to drive the catalytic amplification primary circulation and the hybridization chain reaction secondary circulation, so that the fluorescence signal is amplified, and the ultra-sensitive detection of the target ATP is realized; the reaction condition is mild, the reaction speed is high, the anti-interference capability is strong, and the detection sensitivity is improved.

Drawings

FIG. 1 is a diagram showing the operation of a nucleic acid biosensor constructed according to the present invention.

FIG. 2 is a standard curve of ATP concentration-fluorescence intensity in the examples.

FIG. 3 is a bar graph of the selectivity of the sensor for different interfering analytes.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the following embodiments, but the present invention is not limited by the following embodiments.

Seven DNA probes, namely, a pre-assembled template probe (hereinafter referred to as A, B and S), a reconstituted probe (hereinafter referred to as H), a stimulation probe (hereinafter referred to as F), a fluorescent dye Dabcy1, a FAM-modified hairpin probe 1 (hereinafter referred to as H1) and a hairpin probe 2 (hereinafter referred to as H2), were designed in the examples of the present invention.