CN112114142A - Detection test strip based on quantum dot mark and preparation method and application thereof - Google Patents
Detection test strip based on quantum dot mark and preparation method and application thereof Download PDFInfo
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- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
- G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
- G01N33/569—Immunoassay; Biospecific binding assay; Materials therefor for microorganisms, e.g. protozoa, bacteria, viruses
- G01N33/56911—Bacteria
- G01N33/56916—Enterobacteria, e.g. shigella, salmonella, klebsiella, serratia
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Abstract
The invention discloses a salmonella detection test strip based on quantum dot labeling and a preparation method thereof, belonging to the field of food safety detection. The detection of the salmonella is realized by connecting ZnS: Mn quantum dots with a salmonella aptamer as a signal probe and utilizing a test strip chromatography principle. The test paper strip consists of a sample pad, a nitrocellulose membrane (NC membrane), absorbent paper and a back plate. And (3) utilizing a Biodot three-dimensional spraying point instrument to spray and fix the aptamer complementary sequence connected with streptavidin and Poly A on an NC membrane to form a detection line T line and a quality control line C line. The quantum dot and the salmonella aptamer (the aptamer contains a Poly T sequence) are coupled to be used as a signal probe, and when the signal probe is mixed with a sample solution and then dripped on a sample pad, the sample pad flows through an NC membrane to migrate to water absorbent paper due to the action of capillary force caused by the water absorbent paper. And detecting the salmonella according to the fluorescence intensity ratio of the T line and the C line.
Description
Technical Field
The invention belongs to the field of food safety detection, and particularly relates to a salmonella detection test strip based on quantum dot labeling, and a preparation method and application thereof.
Background
Food-borne diseases become global public health problems, wherein the incidence rate of the food-borne diseases caused by food-borne pathogenic bacteria is the highest, and the food-borne diseases pose great threat to human health. According to the report of the State health council on the national food poisoning event 2015, the microbial food poisoning number is the largest, and accounts for 53.7% of the total number of the annual food poisoning. About 3 hundred million people in China are ill with salmonella every year, and account for 70-80% of the total pathogenicity of pathogenic bacteria food-borne diseases. Food poisoning events caused by food-borne pathogenic bacteria are frequently reported in developed countries and developing countries. Among them, salmonella has become an important food-borne pathogenic bacterium causing human infection, food contamination and bacterial food poisoning worldwide. However, the traditional food-borne pathogenic bacteria detection method has certain defects in detection time, sensitivity and specificity, and cannot meet increasingly strict detection requirements. Therefore, the development of a detection method which is quicker, more convenient, higher in sensitivity and better in specificity has important significance for guaranteeing the food safety.
Aptamers (aptamers) are a class of single-stranded oligonucleotide sequences obtained by in vitro screening that bind tightly to the specificity of the corresponding ligand. The high-order structure formed by the oligonucleotide sequence can identify any type of corresponding target substance such as protein and low molecule, and has high affinity with the target substance. Compared with antibodies, aptamers have the advantages of wide target molecule range, in-vitro screening, easy artificial synthesis and modification, small molecules, good stability, insensitivity to temperature and easy storage, and have been widely applied to clinical diagnosis, clinical treatment, drug delivery, proteome research and food safety as recognition molecules.
In recent years, the rapid development of new nanomaterials in analytical detection is favored by more and more researchers, and many nanomaterials with excellent characteristics are emerging. The magnetic nano material is widely applied to the fields of food safety detection, biomedical detection and the like by virtue of excellent performance and unique structure of the magnetic nano material. The magnetic nano material has wide application in the separation and enrichment of food-borne pathogenic bacteria. Food-borne pathogenic bacteria polluted in food are usually small in quantity, and the conventional analysis method cannot be used for quickly and efficiently detecting the food-borne pathogenic bacteria. The magnetic nano material which is subjected to functional and biological modification can well identify pathogenic bacteria which are usually difficult to detect, and can enrich and separate a small amount of food-borne pathogenic bacteria in food under the action of an external magnetic field. Quantum Dots (QDs) are three-dimensional clusters consisting of a finite number of atoms, all of which are on the nanometer scale in 3 dimensions. The size of the quantum dot is generally between 1 nm and 10nm, electrons and holes are limited by quanta through small particle size, a continuous energy band is changed into a discrete energy level structure with molecular characteristics, fluorescence is emitted under the irradiation of exciting light, and the light absorption and emission characteristics of the quantum dot can be changed by regulating and controlling the size of the quantum dot. The wide wavelength excites narrow wavelength emission, higher fluorescence quantum yield and good biocompatibility, so that the quantum dots arouse wide interest of researchers in the field of life science, and the quantum dots are widely applied to numerous fields such as biomedical imaging, drug screening, photodynamic therapy, biosensors and the like.
Disclosure of Invention
Aiming at the problems in the prior art, the applicant of the invention provides a salmonella detection test strip based on quantum dot marking, and a preparation method and application thereof. The method is simple and convenient to operate, simple in process and capable of being used for on-site rapid screening of port units for salmonella detection.
The technical scheme of the invention is as follows:
the test paper strip based on the quantum dot mark comprises a sample pad, a nitrocellulose membrane NC (numerical control) membrane, absorbent paper and a back plate, wherein the NC membrane is pasted on the back plate, the sample pad and the absorbent paper are respectively pasted at two ends of the NC membrane and coincide with the edge of the NC membrane by 2-4mm, a detection line T line and a quality control line C line are arranged on the NC membrane, the interval between the T line and the C line is 5mm, a binder of a streptavidin and biotin modified aptamer complementary chain is sprayed on the T line, and a binder of streptavidin and biotin modified Poly A is sprayed on the C line.
The preparation method of the test strip is as follows:
s1: firstly, adhering an NC film on a back plate, and then respectively adhering a sample pad and absorbent paper on the upper side and the lower side of the NC film to cover the edge of the NC film by about 2-4 mm;
s2: taking 50 mu L of 0.125mg/mL streptavidin SA solution, and adding a biotin modified aptamer complementary chain to obtain a conjugate solution 1; taking 50 mu L of 0.125mg/mL streptavidin SA solution, adding biotin modified Poly A to obtain a conjugate solution 2, respectively incubating the solution 1 and the solution 2 in a shaking table at 37 ℃ and 180RPM overnight, and spraying the incubated conjugate solution 1 and the incubated conjugate solution 2 on a T line and a C line of an NC membrane by using a Biodot XYZ 3050 three-dimensional point spraying instrument in a spraying amount of 1.0 mu L/cm respectively to obtain sprayed test paper;
s3: and (4) drying the test paper sprayed in the step S2 for 2h at 37 ℃ to fix the T line and the C line on an NC membrane, finally cutting the test paper into test paper strips with the width of 4mm by using a slitter, and placing the test paper strips in a refrigerator at 4 ℃ for later use.
The concentration of solution 1 in S2 was: 0.15-0.3 μ M; the concentration of solution 2 was: 0.15-0.3. mu.M.
An application of a detection test strip based on quantum dot labeling in salmonella detection.
The specific application method is as follows:
step 1: and mixing 30 mu L of a sample to be detected with 50 mu L of a signal probe, performing oscillation incubation at 37 ℃ and 180RPM for 2.5h to obtain a mixed solution, dropwise adding 30 mu L of the mixed solution on a sample pad, washing by using 50 mu L of heavy suspension buffer solution after 15min, and observing the result under an ultraviolet lamp box.
The signal probe is prepared by the following method:
and adding 4 mu L of 100 mu M salmonella amino aptamer solution into ZnS: Mn quantum dot solution, mixing to obtain a mixed solution, placing the mixed solution in a shaking table at 37 ℃ in a dark place, carrying out oscillation incubation at 180RPM for 16h, centrifuging the mixed solution in a centrifuge at 4 ℃ and 8000r/min for 3min after the incubation is finished, removing the unconnected aptamer, re-dispersing the precipitate in a re-suspension buffer solution, and storing the re-dispersed solution at 4 ℃ in a dark place for later use to obtain the signal probe.
The heavy suspension buffer solution is PBS buffer solution, the pH value of the buffer solution is 7.4, and the components comprise 0.5 percent of PEG, 0.25 percent of Tween-20, 5 percent of sucrose and 0.02 percent of MgSO 44、0.05％(NH4)2SO4。
The concentration of the ZnS-Mn quantum dot solution is 5-10 mg/mL; the mass molar ratio of the ZnS to Mn quantum dots to the salmonella amino aptamer is 1.25-2.5 multiplied by 107g/mol。
According to the invention, ZnS: Mn quantum dots and salmonella aptamer (the aptamer contains a Poly T sequence) are coupled to be used as a signal probe, and when the signal probe is incubated with a solution to be detected and then dripped on a sample pad, the sample pad flows through an NC membrane to migrate to absorbent paper due to capillary force action caused by the absorbent paper. When the sample to be detected does not contain salmonella, the signal probe is in an idle state, firstly combines with a complementary sequence of a T line when flowing through an NC membrane, and the rest signal probe is combined with a C line Poly A. After detection, the fluorescent material is observed by an ultraviolet lamp box, and the T line and the C line both display fluorescence. When the sample contains Salmonella, the signaling probe first binds to the bacteria, does not bind to the complementary strand when passing through the T-line, and remains bound to the C-line when passing through the C-line. When the sample is observed under an ultraviolet lamp box, the C line has fluorescence, and the T line disappears or weakens the fluorescence according to the concentration of bacteria in the sample
The beneficial technical effects of the invention are as follows:
according to the invention, ZnS-Mn quantum dots are used as signal molecules and are connected with a salmonella aptamer to form a signal probe, the signal probe is incubated with salmonella, and the detection of the salmonella is realized by utilizing the lateral chromatography principle of a test strip and is used for detecting a pork reagent sample. The method has the lowest visual detection limit of 1.86 × 103CFU/mL, drawing a standard curve of the relative fluorescence intensity of the test strip T line and the test strip C line and the logarithm value of the concentration of the bacterial liquid to obtain that the test strip is 1.86 multiplied by 102CFU/mL to 1.86X 106The linearity in the CFU/mL range is good.
The method is simple and convenient to operate, simple in process and capable of being used for site rapid screening of port units for salmonella detection.
2, the aptamer is used for realizing specific capture on the detected substance, so that the stability and accuracy of detection are effectively improved.
Compared with the antibody, the aptamer has the advantages of artificial synthesis, no dependence on animals and cells, short cycle, low cost, small batch-to-batch difference, convenient chemical modification, good stability and long-term storage.
And 4, by using the quantum dots with high fluorescence quantum yield, the detection background is low, and the detection sensitivity is greatly improved.
Drawings
FIG. 1: a quantum dot mark-based salmonella detection test strip schematic diagram.
FIG. 2: absorption spectrum of Mn quantum dots (a) in example 1; emission spectra of ZnS: Mn quantum dots (254nm excitation) and observed effect under UV light box (inset) (b).
FIG. 3: aptamer concentration in supernatant before and after conjugation in example 1 (Apt 0: supernatant before conjugation; Apt 1: supernatant after conjugation) (a); signal probe probes pass through the nanodrop scanned ultraviolet spectrum (QDs-Apt: quantum dot-aptamer probe, QDs: ZnS: Mn quantum dot) (b).
FIG. 4: the test results of the test strips for salmonella typhimurium bacterial liquid with different concentrations in test example 1 were obtained.
FIG. 5: the fluorescence intensity curve (a) of the test results of the test strips for salmonella typhimurium of different concentrations in test example 1; and (b) a standard curve of the relative fluorescence intensity of the T line and the C line and the log value of the bacterial liquid concentration.
Detailed Description
The present invention will be described in detail with reference to the accompanying drawings and examples.
Example 1:
preparing the test strip:
s1: firstly, adhering an NC film on a back plate, and then respectively adhering a sample pad and absorbent paper on the upper side and the lower side of the NC film to cover the edge of the NC film by about 2 mm;
s2: taking 50 mu L of 0.125mg/mL Streptavidin (SA) solution, and adding biotin modified aptamer complementary strand to obtain solution 1; taking 50 mu L of 0.125mg/mL Streptavidin (SA) solution, adding biotin modified Poly A to obtain solution 2, respectively placing the solution 1 and the solution 2 in a shaking table, incubating at 37 ℃ and 180RPM overnight, and spraying the incubated conjugate solution 1 and the incubated conjugate solution 2 on a T line and a C line of an NC membrane by using a Biodot XYZ 3050 three-dimensional point spraying instrument in a spraying amount of 1.0 mu L/cm respectively to obtain sprayed test paper;
s3: and (4) drying the test paper sprayed in the step S2 for 2h at 37 ℃ to fix the T line and the C line on an NC membrane, finally cutting the test paper into test paper strips with the width of 4mm by using a slitter, and placing the test paper strips in a refrigerator at 4 ℃ for later use.
Preparation of a signal probe:
and adding 4 mu L of 100 mu M salmonella amino aptamer solution into ZnS: Mn quantum dot solution, mixing to obtain a mixed solution, placing the mixed solution in a shaking table at 37 ℃ in a dark place, carrying out oscillation incubation at 180RPM for 16h, centrifuging the mixed solution in a centrifuge at 4 ℃ and 8000r/min for 3min after the incubation is finished, removing the unconnected aptamer, re-dispersing the precipitate in a re-suspension buffer solution, and storing the re-dispersed solution at 4 ℃ in a dark place for later use to obtain the signal probe.
Example 2
Preparing the test strip:
s1: firstly, adhering an NC film on a back plate, and then respectively adhering a sample pad and absorbent paper on the upper side and the lower side of the NC film to cover the edge of the NC film by about 3 mm;
s2: taking 50 mu L of 0.125mg/mL Streptavidin (SA) solution, and adding biotin modified aptamer complementary strand to obtain solution 1; taking 50 mu L of 0.125mg/mL Streptavidin (SA) solution, adding biotin modified Poly A to obtain solution 2, respectively placing the solution 1 and the solution 2 in a shaking table, incubating at 37 ℃ and 180RPM overnight, and spraying the incubated conjugate solution 1 and the incubated conjugate solution 2 on a T line and a C line of an NC membrane by using a Biodot XYZ 3050 three-dimensional point spraying instrument in a spraying amount of 1.0 mu L/cm respectively to obtain sprayed test paper;
s3: and (4) drying the test paper sprayed in the step S2 for 2h at 37 ℃ to fix the T line and the C line on an NC membrane, finally cutting the test paper into test paper strips with the width of 4mm by using a slitter, and placing the test paper strips in a refrigerator at 4 ℃ for later use.
Preparation of a signal probe:
and adding 4 mu L of 100 mu M salmonella amino aptamer solution into ZnS: Mn quantum dot solution, mixing to obtain a mixed solution, placing the mixed solution in a shaking table at 37 ℃ in a dark place, carrying out oscillation incubation at 180RPM for 16h, centrifuging the mixed solution in a centrifuge at 4 ℃ and 8000r/min for 3min after the incubation is finished, removing the unconnected aptamer, re-dispersing the precipitate in a re-suspension buffer solution, and storing the re-dispersed solution at 4 ℃ in a dark place for later use to obtain the signal probe.
Example 3
Preparing the test strip:
s1: firstly, adhering an NC film on a back plate, and then respectively adhering a sample pad and absorbent paper on the upper side and the lower side of the NC film to cover the edge of the NC film by about 4 mm;
s2: taking 50 mu L of 0.125mg/mL Streptavidin (SA) solution, and adding biotin modified aptamer complementary strand to obtain solution 1; taking 50 mu L of 0.125mg/mL Streptavidin (SA) solution, adding biotin modified Poly A to obtain solution 2, respectively placing the solution 1 and the solution 2 in a shaking table, incubating at 37 ℃ and 180RPM overnight, and spraying the incubated conjugate solution 1 and the incubated conjugate solution 2 on a T line and a C line of an NC membrane by using a Biodot XYZ 3050 three-dimensional point spraying instrument in a spraying amount of 1.0 mu L/cm respectively to obtain sprayed test paper;
s3: and (4) drying the test paper sprayed in the step S2 for 2h at 37 ℃ to fix the T line and the C line on an NC membrane, finally cutting the test paper into test paper strips with the width of 4mm by using a slitter, and placing the test paper strips in a refrigerator at 4 ℃ for later use.
Preparation of a signal probe:
and adding 4 mu L of 100 mu M salmonella amino aptamer solution into ZnS: Mn quantum dot solution, mixing to obtain a mixed solution, placing the mixed solution in a shaking table at 37 ℃ in a dark place, carrying out oscillation incubation at 180RPM for 16h, centrifuging the mixed solution in a centrifuge at 4 ℃ and 8000r/min for 3min after the incubation is finished, removing the unconnected aptamer, re-dispersing the precipitate in a re-suspension buffer solution, and storing the re-dispersed solution at 4 ℃ in a dark place for later use to obtain the signal probe.
Test example 1
Commercial pork sample blank sample labeling recovery experiment: pork paste was purchased from snow wave shops in Wuxi European supermarket. Weighing 25g of minced pork, adding 225mL of PBS buffer solution, mashing, centrifuging, taking supernatant, sterilizing at 121 ℃ for 20min, and preparing a sample solution. Culturing salmonella typhimurium in LB liquid culture medium until OD 0.2 is measured by an enzyme labeling instrument, taking 1mL bacterial liquid, centrifuging for 5min at 5000r/min, removing redundant culture medium, washing twice by PBS buffer solution, taking 100 mu L bacterial liquid, and adding 900 mu L sterilized sample solution. The bacterial liquid is diluted by 10 times of gradient with buffer solution to 1.86 multiplied by 105、1.86×104、1.86×103CFU/mL。
50. mu.L of the prepared signal probe prepared in example 1 was taken, and 30. mu.L of the above P was added theretoBS buffer diluted to 1.86X 105、1.86×104、1.86×103CFU/mL concentration of sample solution, placed in 37 degrees C shaking table 180RPM incubation for 2.5 h. 30 mu.L of the mixture of the probe and the sample solution was dropped on the sample pad of the test strip prepared in example 1, and after 15min, 50 mu.L of the resuspension buffer was used for washing, and the results observed under the UV light box are shown in FIG. 4 and are shown in Table 1 below. The result shows that the recovery rate is 96-121% compared with the concentration of the added bacterial liquid, and the method has good accuracy.
TABLE 1 pork standard recovery results
Test example 2
Commercial pork sample blank sample labeling recovery experiment: pork paste was purchased from snow wave shops in Wuxi European supermarket. Weighing 25g of minced pork, adding 225mL of PBS buffer solution, mashing, centrifuging, taking supernatant, sterilizing at 121 ℃ for 20min, and preparing a sample solution. Culturing salmonella typhimurium in LB liquid culture medium until OD 0.2 is measured by an enzyme labeling instrument, taking 1mL bacterial liquid, centrifuging for 5min at 5000r/min, removing redundant culture medium, washing twice by PBS buffer solution, taking 100 mu L bacterial liquid, and adding 900 mu L sterilized sample solution. The bacterial liquid is diluted by 10 times of gradient with buffer solution to 1.86 multiplied by 105、1.86×104、1.86×103CFU/mL。
50. mu.L of the prepared signal probe prepared in example 1 was diluted to 1.86X 10 by adding 30. mu.L of the above PBS buffer, respectively5、1.86×104、1.86×103CFU/mL concentration of sample solution, placed in 37 degrees C shaking table 180RPM incubation for 2.5 h. And (3) respectively dropwise adding 30 mu L of mixed solution of the probe and the sample solution onto the sample pad of the test strip prepared in example 1, washing the sample pad with 50 mu L of heavy suspension buffer solution after 15min, and observing the result under an ultraviolet lamp box, wherein the results are shown in the following table 2. The result shows that the recovery rate is between 91% and 116% by comparing with the concentration of the added bacterial liquid, and the method has good accuracy.
TABLE 2 commercial pork recovery results
Test example 3
Commercial pork sample blank sample labeling recovery experiment: pork paste was purchased from snow wave shops in Wuxi European supermarket. Weighing 25g of minced pork, adding 225mL of PBS buffer solution, mashing, centrifuging, taking supernatant, sterilizing at 121 ℃ for 20min, and preparing a sample solution. Culturing salmonella typhimurium in LB liquid culture medium until OD 0.2 is measured by an enzyme labeling instrument, taking 1mL bacterial liquid, centrifuging for 5min at 5000r/min, removing redundant culture medium, washing twice by PBS buffer solution, taking 100 mu L bacterial liquid, and adding 900 mu L sterilized sample solution. The bacterial liquid is diluted by 10 times of gradient with buffer solution to 1.86 multiplied by 105、1.86×104、1.86×103CFU/mL。
50. mu.L of the prepared signal probe prepared in example 1 was diluted to 1.86X 10 by adding 30. mu.L of the above PBS buffer, respectively5、1.86×104、1.86×103CFU/mL concentration of sample solution, placed in 37 degrees C shaking table 180RPM incubation for 2.5 h. 30 μ L of the mixture of the probe and the sample solution was dropped on the sample pad of the test strip prepared in example 1, and after 15min, 50 μ L of the resuspension buffer was used for washing, and the results were observed under an ultraviolet light box as described in table 3 below. The result shows that the recovery rate is between 98% and 106% by comparing with the concentration of the added bacterial liquid, and the method has good accuracy.
TABLE 3 pork recovery results on the market with a standard
The present invention includes, but is not limited to, the above embodiments, and any equivalent substitutions or partial modifications made within the spirit and principle of the present invention are considered to be within the scope of the present invention.
Claims (8)
1. The test paper strip based on the quantum dot mark comprises a sample pad, a nitrocellulose membrane NC (numerical control) membrane, absorbent paper and a back plate, wherein the NC membrane is pasted on the back plate, the sample pad and the absorbent paper are respectively pasted at two ends of the NC membrane and coincide with the edge of the NC membrane by 2-4mm, and the test paper strip is characterized in that a detection line T line and a quality control line C line are arranged on the NC membrane, the interval between the T line and the C line is 5mm, a binder of a streptavidin and biotin modified aptamer complementary chain is sprayed on the T line, and a binder of streptavidin and biotin modified Poly A is sprayed on the C line.
2. The preparation method of the test strip based on the quantum dot mark of claim 1 is characterized by comprising the following steps:
s1: firstly, adhering an NC film on a back plate, and then respectively adhering a sample pad and absorbent paper on the upper side and the lower side of the NC film to cover the edge of the NC film by about 2-4 mm;
s2: taking 50 mu L of 0.125mg/mL streptavidin SA solution, and adding a biotin modified aptamer complementary chain to obtain a conjugate solution 1; taking 50 mu L of 0.125mg/mL streptavidin SA solution, adding biotin modified Poly A to obtain a conjugate solution 2, respectively incubating the solution 1 and the solution 2 in a shaking table at 37 ℃ and 180RPM overnight, and spraying the incubated conjugate solution 1 and the incubated conjugate solution 2 on a T line and a C line of an NC membrane by using a Biodot XYZ 3050 three-dimensional point spraying instrument in a spraying amount of 1.0 mu L/cm respectively to obtain sprayed test paper;
s3: and (4) drying the test paper sprayed in the step S2 for 2h at 37 ℃ to fix the T line and the C line on an NC membrane, finally cutting the test paper into test paper strips with the width of 4mm by using a slitter, and placing the test paper strips in a refrigerator at 4 ℃ for later use.
3. The method according to claim 2, wherein the concentration of solution 1 in S2 is: 0.15-0.3 μ M; the concentration of solution 2 was: 0.15-0.3. mu.M.
4. An application of a detection test strip based on quantum dot labeling in salmonella detection.
5. The use according to claim 4, characterized in that the specific application method is as follows:
step 1: and mixing 30 mu L of a sample to be detected with 50 mu L of a signal probe, performing oscillation incubation at 37 ℃ and 180RPM for 2.5h to obtain a mixed solution, dropwise adding 30 mu L of the mixed solution on a sample pad, washing by using 50 mu L of heavy suspension buffer solution after 15min, and observing the result under an ultraviolet lamp box.
6. The use of claim 5, wherein the signaling probe is prepared by:
and adding 4 mu L of 100 mu M salmonella amino aptamer solution into ZnS: Mn quantum dot solution, mixing to obtain a mixed solution, placing the mixed solution in a shaking table at 37 ℃ in a dark place, carrying out oscillation incubation at 180RPM for 16h, centrifuging the mixed solution in a centrifuge at 4 ℃ and 8000r/min for 3min after the incubation is finished, removing the unconnected aptamer, re-dispersing the precipitate in a re-suspension buffer solution, and storing the re-dispersed solution at 4 ℃ in a dark place for later use to obtain the signal probe.
7. The use according to claim 5 or 6, wherein the resuspension buffer is PBS buffer, the pH of the buffer is 7.4, and the composition comprises 0.5% PEG, 0.25% Tween-20, 5% sucrose, 0.02% MgSO4、0.05％(NH4)2SO4。
8. The use according to claim 6, wherein the concentration of ZnS: Mn quantum dots solution is 5-10 mg/mL; the mass molar ratio of the ZnS to Mn quantum dots to the salmonella amino aptamer is 1.25-2.5 multiplied by 107g/mol。
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| CN108226509A (en) * | 2017-12-15 | 2018-06-29 | 武汉市农业科学院 | The fluorescence immune chromatography detection method and Test paper of a kind of salmonella typhimurium |
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| WO2017211214A1 (en) * | 2016-06-07 | 2017-12-14 | 江南大学 | Preparation method of salmonella-detecting colloidal gold test strip for food based on salmonella core polysaccharide monoclonal antibody |
| CN107478830A (en) * | 2017-06-14 | 2017-12-15 | 江苏大学 | A kind of ochratoxin A Rapid detection test strip based on aptamers identification |
| CN107796938A (en) * | 2017-10-17 | 2018-03-13 | 中国农业科学院农业质量标准与检测技术研究所 | A kind of aptamer fluorescent test paper strip and its preparation method and application |
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