254results about How to "Highly selective detection" patented technology

The invention discloses a preparation method of an unmarked electrochemiluminescent tumor marker immunosensor and application of the immunosensor in detection of tumor markers, and belongs to the field of novel nano functional materials and biosensors. According to the preparation method of the unmarked electrochemiluminescent tumor marker immunosensor, a novel micro-nano material NH4CoPO4 is taken as a substrate so that the luminescence stability of a luminol-hydrogen peroxide luminescent system can be greatly enhanced, and meanwhile, rod-like gold@siver core-shell nanoparticles are taken as a biomimetic catalytic luminescent system, and therefore, an unmarked electrochemiluminescent immunosensor, which is low in cost, high in sensitivity, good in specificity, fast in detection and simple to prepare and is used for detecting tumor makers, can be prepared.

The invention relates to a method for preparing magnetic DNA (deoxyribonucleic acid) supramolecular hydrogel and application thereof. The magnetic DNA supramolecular hydrogel comprises magnetic oxidized graphene and two types of DNA monomers [Y-type DNA monomers (Y-DNA) and linker DNA monomers (L-DNA)]. The Y-DNA and the L-DNA are hybridized by sticky ends in a complementary manner to form DNA hydrogel; exposed sticky ends of the DNA hydrogel are adsorbed on the surfaces of the magnetic oxidized graphene under pi-pi stacking effects to form the magnetic DNA supramolecular hydrogel. The method and the application have the advantages that the magnetic DNA supramolecular hydrogel prepared by the aid of the method is low in cost, easy to operate and separate and high in reaction speed and universality; the method can be successfully applied to colorimetry and ultraviolet-visible absorption quantitative detection on medicine carriers and adenosine triphosphate (ATP); as compared with existing detection methods, the method is easy and convenient to implement and low in cost and has a broad application prospect, visual detection results can be obtained, and complicated instruments or equipment can be omitted.

The invention relates to a surface-enhanced Raman scattering aptamer sensor for detecting polychlorinated biphenyls and application. Gold-silver core-shell nanoparticles are used as a Raman substrate;4-thiosalicylic acid as a Raman signal molecule is modified on the surface of the gold-silver core-shell nanoparticles; a PCB72 aptamer is used as a pollutant identification element for constructingto obtain the sensor. Compared with the prior art, the surface-enhanced Raman scattering aptamer sensor disclosed by the invention has the advantages that by adopting an advanced surface-enhanced Raman technology, the detection sensitivity of the sensor to PCB72 is greatly improved, the linear detection range of the sensor is 1pg/mL-1000pg/mL and the detection limit can reach 0.3pg/mL; meanwhile,by adopting the aptamer, specific recognition of the PCB72 is realized, and the detection selectivity of the sensor to the PCB72 is greatly improved. The sensor disclosed by the invention can be usedfor detection analysis of an actual water sample; compared with other analysis methods, an analysis method disclosed by the invention has the advantages that a sample does not need complex pretreatment; simplicity, quickness and ultrahigh sensitivity are realized.

The invention discloses an application of an electrochemiluminescence biosensor based on cytosine (C)-containing cyclic DNA sequences where in-situ reduced Ag nano-clusters are enriched as signal probes and adopting dual amplification strategy to detection of target thrombin. According to the technical scheme, DNA cleavage enzyme with hairpin DNA recognition capability and catalysis effect is designed, when target thrombin exists, hairpin DNA is opened, and substrate DNA is cleaved under the action of Zn<2+>; a large quantity of cytosine (C)-containing cyclic DNA sequences are aggregated through HCR (hybridization chain reaction), in-situ reduction of AgNO3 is performed on the electrode surface by NaBH4, a large quantity of Ag nano-clusters are formed, and the electrochemiluminescence biosensor with dual amplification effect is prepared. The sensor is subjected to luminescence detection, and a linear relation is formed between light-emitting signals and concentration of a to-be-testedsample. The Ag nano-cluster signal probes and the DNA dual amplification technology are combined for rapid and high-sensitivity detection of thrombin, and the electrochemiluminescence biosensor has great application potential in early clinical analysis and detection.

The invention relates to a reactive rhodamine fluorescent probe for detecting mercury ions, and a preparation method thereof. A structural formula of the reactive rhodamine fluorescent probe RBHA is shown in the description. The preparation method comprises the steps of adding rhodamine B and hydrazine hydrate into a solvent, reacting for 1-2 h under refluxing at a temperature of 80-90 DEG C; carrying out rotary evaporation; adding water and adjusting pH; filtering; and purifying to obtain rhodamine B hydrazide; dissolving the rhodamine B hydrazide and glyoxylic acid in a solvent; reacting overnight with stirring at a room temperature; filtering; and purifying to obtain the reactive rhodamine fluorescent probe. The reactive rhodamine fluorescent probe has high selectivity for the mercury ions, has no obvious interference with other common ions, can work in an environment with a wide pH scope ranging from 5 to 10, and has application prospects in bioluminescent imaging and analysis of environmental water samples.

The invention relates to a preparation method of a hydrogen sulfide gas sensor, in particular to a gas-sensitive sensor established based on a novel two-dimensional composite nanomaterial and belongs to the technical field of novel nano functional materials and environment monitoring. The sensor can be used for detecting the content of hydrogen sulfide gas in an environment. A cerium and magnesium bi-metal co-doped titanium dioxide nanosheet in-situ composite carbon nitride two-dimensional composite nanomaterial CeMn-TiO2/g-C3N4 is prepared firstly. Through the characteristics that the material has the large specific area, and high mesoporous gas adsorption and multiple characteristics that electron transfer affects sensitivity due to the material surface gas change, the gas-sensitive sensor which is sensitive to and rapidly responds to the hydrogen sulfide gas is established.

The invention discloses a photoelectrochemical sensor for estradiol based on a boron-doped iron cobalt oxide two-dimensional nano composite material as well as a preparation method and application of the photoelectrochemical sensor. The preparation method comprises the following steps: firstly, modifying a two-dimensional nano material g-C3N4 on ITO (Indium Tin Oxide) conductive glass by adopting an electrodeposition method; secondly, carrying out in-situ grown of iron cobalt oxide by adopting a hydrothermal method, and further preparing to obtain a working electrode loaded with the g-C3N4, doped with boron and modified by the iron cobalt oxide Bi@Fe*Co<1->*O3/g-C3N4; finally, loading an estradiol antibody by using good biocompatibility and large specific surface area of the material. During detection, L-ascorbic acid-2-trisodium phosphate (AAP) can be catalyzed by boron-doped iron cobalt oxide Bi@Fe*Co<1->*O3 to generate L-ascorbic acid AA in situ, further an electron donor is provided for photoelectric detection, and then photocurrent intensity is correspondingly reduced by using the influence of specific combination of the antibody and antigen on electronic transmission capacity; finally, the construction of the photoelectrochemical sensor for the estradiol by adopting a mark-free photoelectrochemical detection method is realized.

The invention discloses a carbon nitride-binary metal boron oxide composite material-based bisphenol A photochemical sensor and preparation and application thereof. The preparation comprises the steps of firstly modifying a two-dimensional nano material g-C3N4 on ITO conductive glass by adopting an electrodeposition method; growing nickel-cobalt hydroxide in situ by adopting a hydrothermal method to prepare a g-C3N4-loaded and boron-doped nickel-cobalt oxide Bi@NixCo<1-x>O3/g-C3N4-modified working electrode; and finally loading a bisphenol A antibody by adopting good biocompatibility and large specific surface area of the material, thereby completing preparation of the bisphenol A photochemical sensor. When the detection is implemented, L-ascorbic acid-2-trisodium phosphate APP can be catalyzed by the boron-doped nickel-cobalt oxide Bi@NixCo<1-x>O3 to generate the L-ascorbic acid AA in situ, so that an electron donor is provided for photoelectric detection, the photocurrent strength is correspondingly reduced by utilizing the influence on the electronic transmission capability caused by the specificity quantitative combination of the antibody and antigen, and construction of a photoelectric sensor for detecting the bisphenol A by using an unmarked photoelectrochemical technique is finally achieved.

The invention discloses a preparation method and application of blue-fluorescence carbon quantum dots, and belongs to the technical field of carbon quantum dots. Citric acid and hyaluronic acid are dissolved into water to obtain a mixed solution A; the mixed solution A is subjected to a hydrothermal reaction for 4-12 hours to obtain an HA-CDs solution; the HA-CDs solution is dialysed by using a dialysis membrane and then centrifuged, after standing, supernatant liquid is taken to obtain the blue-fluorescence carbon quantum dots. The hyaluronic acid and the citric acid are used as synthesizingraw materials, the novel carbon quantum dots high in fluorescence intensity is synthesized in one step, high-selectivity detection of folic acid can be achieved, and the carbon quantum dots which areeasily synthesized are applied in biological recognition.

The invention discloses a preparation method of an electrogenerated chemiluminescence sensor, and belongs to the technical field of novel nano-functional materials and biosensors. A novel two-dimensional nano-composite material is firstly prepared, manganese doped titanium dioxide nano-blocks are compounded with molybdenum disulfide in situ to form the two-dimensional nano-composite material Mn-TiO2/MoS2, aflatoxin antibodies are loaded by the aid of excellent biocompatibility and large specific surface area of the material, manganese doped titanium dioxide can catalyze hydrogen peroxide to generate O2 in situ when the aflatoxin is detected, electrochemical reaction of O2 and K2S2O8 in base solution are performed to generate electrogenerated chemiluminescence signals, electronic transmission capacity is affected by specific quantitative combination of the antibodies and antigen, so that current intensity is reduced, luminescent intensity is reduced, and the electrogenerated chemiluminescence sensor for detecting the aflatoxin by an unmarked electrogenerated chemiluminescence method is finally prepared.

The invention relates to the technical field of molecular biology, and in particular relates to a self-assembly probe based on configuration change and a label-free detection method for exosomes. Whenexosomes exist, are exosomes surface markers, protein tyrosine kinases-7 (PTK 7) specifically binds to the aptamer, changes the configuration of the recognition probe, releases the trigger chain, andthus binds to G-R DNA undergoes strand displacement reaction, exposing G-rich sequence to form G-quadruplex. NMM is embedded in G-quadruplex, generating strong fluorescence signal, realizing label-free sensitive detection of exosomes. Under the optimized experimental conditions, the linear range is 5*10<5> to 5*10<7> particles/mu L, and the minimum detection limit is 3.4*10<5> particles/mu L. Theprobe is used to prepare a highly sensitive and highly selective detection kit for detecting exosomes in actual blood samples.

The invention relates to a manufacturing method for a hydrogen peroxide non-enzyme sensor based on a silver-graphene nano composite. The manufacturing method comprises the following specific steps of: 1) weighing 5-10mg of graphene oxide, and dissolving the graphene oxide into 5-10 mL of water, thereby obtaining a brown yellow graphene oxide solution; 2) taking a mixed solution containing AgNO3 and KNO3 as an electro-deposition solution; 3) transferring and dispensing 10-15muL of the graphene oxide solution obtained in the step 1) to the surface of a pre-treated glass carbon electrode, and drying in air at the room temperature, thereby obtaining a graphene oxide modified glass carbon electrode; and 4) taking the graphene oxide modified glass carbon electrode as a working electrode, taking a platinum wire electrode as a counter electrode, taking a statured mercurous chloride electrode as a reference electrode, putting the electrodes into the electro-deposition solution prepared in step 2), depositing for 1-3 minutes under constant potential within a range of -0.55V to -0.75V, thereby obtaining a silver-graphene nano composite modified electrode which is used as the hydrogen peroxide non-enzyme sensor. The sensor realizes quick, sensitive and high-selection detection on hydrogen peroxide, and has remarkable advantages in comparison with sensors reported in existing literature.

The invention discloses a preparation method of an electrochemical diethylstilbestrol sensor based on a titanium-dioxide-based two-dimensional composite nanomaterial and belongs to the technical field of novel nano functional materials and biosensors. A novel two-dimensional flaky magnetic nano light-sensitive material FeCo-N@TiO2 is prepared firstly; through good bio-compatibility, the large specific area and ferromagnetism of the material, a diethylstilbestrol antibody is loaded, then horse radish peroxidase is fixed through the interlinking effect of glutaraldehyde, in the detection process, due to the fact that horse radish peroxidase can catalyze hydrogen peroxide, electrochemical signals are generated, through the influences of specific quantitative combination of the antibody and an antigen on electron transmission capacity, the current intensity is correspondingly reduced, and finally the electrochemical biosensor which is low in cost, high in sensitivity, good in specificity, rapid in detection and easy to prepare and detects diethylstilbestrol is prepared.

The present invention discloses a preparation method of a label-free electrochemical immunosensor for nonyl phenol detection, and belongs to the technical field of novel nanometer function materials and environment detection. According to the present invention, the molybdenum disulfide/gold-palladium alloy nanometer composite material MoS2/AuPd is prepared by using the one-pot method, and then the simple, rapid and sensitive label-free electrochemical immunosensor for nonyl phenol detection in real samples is prepared through the excellent adsorption performance and the excellent electrochemical catalytic performance of the molybdenum disulfide/gold-palladium alloy nanometer composite material MoS2/AuPd.

The invention provides a three-dimensional flower-like nano composite material as well as a preparation method and application thereof, the composite material is NiO/PDDA-RGO, and the material is prepared from PDDA-RGO and synthesized NiO by hydrothermal reaction and calcining via an ultrasonic-assisted method. Reduced graphene oxide in the composite material is used as a NiO carrier, so that theproblem of low NiO conductivity is solved, the adsorption characteristic of an analyte is improved to enhance the electrochemical performance, and the composite material is an excellent electrode modification material. The NiO/PDDA-RGO composite material is modified on the surface of an electrode to construct electrochemical sensing for enzyme-free nitrite detection. According to the method, thetechnical problems of long recognition time, complexity, high cost, low sensitivity, unobvious recognition effect and the like in the prior art are solved, high-sensitivity and high-selectivity detection for nitrite in a complex environment can be realized, and the composite material has a very good application prospect in the analysis fields of environments, foods and the like.

The invention provides a biosensor for detecting Hg<2+> and a preparation method thereof, which can be used in the fields of environmental monitoring, medical treatment and public health, food safety, life sciences and the like. According to the biosensor, a gold nanocage is combined with a Hg<2+> recognition probe by utilizing a surface positive charge modification technique and electrostatic interaction, so that a nanocarrier with a molecular biological door is constructed, and a single-stranded DNA molecular door which is rich in T basic groups is opened through specific molecular recognition reaction, so that fluorescent molecules are released, and the detection of fluorescent signals is realized. Therefore, by utilizing the biosensor, the high-sensitivity and high-selectivity detection of Hg<2+> can be realized. Additionally, on the basis of a controlled release technique of guest molecules in the nanocarrier of the biosensor, a new way and method is provided for the delivery of tumor targeted drugs and the clinical diagnosis and treatment of serious diseases.

The invention discloses a preparation method of electrochemical sensor for sulfonamide molecule, and belongs to the technical field of new nano functional materials and biosensor. The method firstly prepares a nickel hydroxide nanosheet array on a disposable throwable electrode, and uses the large specific surface area and a high activity hydroxyl functional group and an amino functional group ofpolydopamine to sequentially prepare a polydopamine film containing an electron mediator and a molecularly imprinted polymer taking a sulfonamide molecule as a template molecule directly on the nickelhydroxide nanosheet array by adopting an in-situ growth method, after eluting the template molecule, the position of the original template molecule becomes a hole, that is, the molecularly imprintedpolymer eluting the template molecule, thus, an electrochemical sensor for the sulfonamide molecule is prepared.

The invention discloses a organic small molecule containing a boron-nitrogen coordination bond, and a preparation method and sensing application thereof to a fluorine ion, and belongs to the technicalfield of preparation of fluorescent compounds and preparation of fluorescent probes. According to the invention, 2-(3-bromobenzothiophen-2-yl)benzothiazole reacts with n-butyl lithium to form a lithium reagent, and then the lithium reagent reacts with triphenylboron to prepare the small molecule containing the boron-nitrogen coordination bond. Experiments verify that the small molecule containingthe boron-nitrogen (BN) coordination bond prepared by the invention can successfully realize selective recognition of the fluorine ion. The preparation method of the fluorescent compound containing the boron-nitrogen (BN) coordination bond of the invention is simple and convenient, the reaction condition is mild, and a prepared fluorescent probe has the characteristics of photochemical stabilityand good selectivity.