143results about How to "Enables ultra-sensitive detection" patented technology

The invention relates to a making method and an application of a mycotoxin photoelectrochemical sensor for in situ generation of CdS. The method uses cerium dioxide doped reduced graphene oxide as an antibody capture substrate, and the cerium dioxide doped reduced graphene oxide has good conductivity and large specific surface area, and can effectively reduce background signals. Na2S is directly dropped to the surface of an electrode with Cd<2+> functionalized porous TiO2 nanoparticles as a semiantigen marker carrier in order to realize in situ generation of narrow band gap CdS with a high photoelectric conversion rate, and a photoelectric current signal can be generated through irridating the CdS by an LED lamp of visible light wavelength. The carrier TiO2 can be well matched with the energy band of the CdS in order to further improve the photoelectric conversion signal of the CdS, so the competitive photoelectrochemical sensor for super sensitive detection of zearalenone, alpha-zeranol, aflatoxin B1, aflatoxin B2, ochratoxin A, ochratoxin B and other mycotoxins is made.

The invention relates to a making method and an application of a CdS sensitized TiO2 environmental estrogen photoelectrochemical sensor. The method uses TiO2 as an antigen capture substrate material, a CdS photoelectric active material is in situ generated on the surface of a Cd2<+> functional TiP nanomaterial maker modified electrode through a direct Na2S dropping technology, and CdS is irritated by an LED lamp of visible light wavelength to be converted to a photoelectric current signal. The substrate material TiO2 can be well matched with CdS energy band, so the photocurrent conversion signal of CdS is further improved, thereby the competitive photoelectrochemical immunosensor for ultra sensitive detection of estradiol, estriol, diethylstilbestrol, bisphenol A, nonylphenol, oestrone and other environmental pollutants is made.

The invention relates to a gold nanoparticle-molybdenum disulfide-gold ultra-sensitive SERS substrate material and a preparation method thereof. The structure is a gold nanoparticle/molybdenum disulfide/gold sandwich structure with the gold nanoparticle as a core, the molybdenum disulfide as a shell, and a layer of gold particles with a certain "hot sopt" effects evaporated on the surface of the core-shell structure in a vacuum mode. The molar ratio of the nano-material element is molybdenum: sulfur: gold being 1.0:1.9: 1.0. The chemical formula of molybdenum disulfide is MoS2. Compared with the prior art, the preparation method of the gold nanoparticle-molybdenum disulfide-gold ultra-sensitive SERS substrate material is convenient and fast. According to the gold nanoparticle-molybdenum disulfide-gold SERS substrate material, MoS2 serves as a supporting body to adsorb target molecules, a double-plasma coupling effect exists between the Au nano particles, the "hot spot" effect enhancedan SERS signal, the MoS2 is in bridge connection with the Au so as to realize the ultra-sensitive detection of rhodamine B molecules, the detection limit can reach 10-10 mol/L, and the repeatability and the stability of the rhodamine B is detected to be good.

The invention relates to a preparation method and application of a multilevel micro-meter cubic zinc stannate composite material based photoelectrochemical sensor to cardiac troponin I and belongs tothe field of photoelectrochemical sensors. Polypyrrole/ nitrogen subtracted graphite phase carbon nitride is taken as a template for synthesis of a multilevel structural Zn2SnO4 cube; nitrogen and sulfur doped graphene quantum dot N,S-GQDs is used for sensitizing Zn2SnO4 to improve its visible light absorption; the process of in-situ growth of CdS nanoparticles is carried out to obtain a multilevel micro-meter cubic zinc stannate composite material Zn2SnO4/N,S-GQDs/Cds with photoelectric activity improved greatly; cardiac troponin I antibodies, bovine serum albumin and cardiac troponin I antigens are assembled to the composite material Zn2SnO4/N,S-GQDs by means of the layer by layer self-assembly; thus, according to the excellent photoelectric activity of Zn2SnO4/N,S-GQDs and binding of specificity of cardiac troponin I antigens and cardiac troponin I antibodies, ultra-sensitive detection to cardiac troponin I is achieved, which has a great significance in analysis and detection of cardiac troponin I.

The invention relates to a preparation method of a photoelectrochemical sensor for detecting dexamethasone based on in-situ generation of cadmium sulfide. The method specifically comprises the following steps: as carboxylated carbon nitride and bismuth sulfide are taken as substrate materials, and labeling a dexamethasone antibody by using titanium dioxide subjected to cadmium ion functionalization. Sodium sulfide is directly dropwise added to the electrode surface, a narrow band-gap cadmium sulfide semiconductor nanometer material with the high photoelectric conversion efficiency is generated in situ, and a photocurrent signal is generated under light source irradiation with visible wavelength. A porous titanium dioxide carrier and a cadmium sulfide energy band are well matched, so that the photoelectric conversion efficiency of the cadmium sulfide is improved, the high-sensitivity detection of dexamethasone is realized, and the detection limit is 2pg/mL.

The invention discloses a preparation method of a label-free photoelectrochemical sensor for zearalenone. According to a construction method of a sensing interface, a nano copper-cobalt-iron material,polylysine and nano-rutile type TiO2 mesoscopic crystals are taken as construction elements, and a zearalenone antibody (Ab) is further immobilized; due to the surface plasma effect of the nano copper-cobalt-iron material and the excellent conductivity of the polylysine, the sensing interface can accelerate the photo-induced electron transfer rate of the nano-rutile type TiO2 mesoscopic crystalsand improve photocurrent signals of the nano-rutile type TiO2 mesoscopic crystals; furthermore, the polylysine is rich in amino, thus being conducive to the load of the antibody; when the zearalenoneand the immobilized zearalenone antibody generate an immunoreaction, the photoelectric signals at the sensing interface are significantly weakened due to a steric hindrance effect. A label-free photoelectric sensing method established based on the phenomenon can realize high sensitive detection of the zearalenone having a concentration within a range of 1*10<-6>-10ng/mL.

The invention relates to the technical field of a biosensor, and particularly relates to a fluorescence biosensor for detecting UDG (Uracil-DNA Glycosylase) on the basis of a polymerase-assisted feedback rolling circle amplification and endonuclease amplification fluorescence method. The invention aims to solve problems of both low specificity and low sensitivity of a method for detecting UDG in the prior art. The biosensor for detecting the UDG on the basis of a feedback rolling circle amplification technology achieves a rolling circle amplification effect on matching of phi29 polymerase andendonuclease IV, implements fluorescence resonance energy transfer of a fluorophore and a Quenching group and performs a homogeneous reaction on mixed liquid. A preparation method comprises: constructing a circular template and a composite probe; feeding back a rolling circle amplification signal and carrying out fluorescence detection. Specific hydrolysis of the UDG on a basic group U is utilized, and by utilizing such specific reaction, the UDG can be accurately measured and meanwhile, interference can also be avoided; by utilizing endonuclease IV circle amplification, a signal amplificationeffect is achieved.

The invention discloses a photoelectric chemical detection method of zearalenone based on a TiO2 mesocrystal. According to the method, a polydopamine-sensitized rutile type TiO2 mesocrystal is used as a photoelectric active substrate material and is applied to an immobilization zearalenone antibody; a mesoporous cobaltosic oxide marked zearalenone secondary antibody is used as a signal probe; a photoelectric chemical sensor based on a sandwich immune recognition mode is prepared by using a signal amplification effect of the probe on the substrate material and is applied to quantitative detection of zearalenone; based on stability and high conductivity of polydopamine, polydopamine and an RTM composite can accelerate transferring speed of photoinduced electrons and increasing photocurrent signals; through a sandwich immune recognition process, OMCO with competitive light-harvesting capability is introduced into a sensing interface; and high-sensitivity detection on zearalenone in a concentration range of 1x10<-6>ng/Ml-20ng/mL can be achieved.

The invention provides a preparation method of an electrochemical sensor for detecting heavy metal ions. The preparation method includes the following steps: 1) performing carboxyl functionalization to multi-wall carbon nano-tubes and performing in-situ synthesis with zirconium chloride and 2-aminoterephthalatic acid to prepare an MWCNTs@UiO-66-NH2 composite material; 2) dispersing the MWCNTs@UiO-66-NH2 composite material in N,N-dimethylformamide to prepare a suspension liquid, drop-coating a surface of a glass carbon electrode with the suspension liquid until the surface of the glass carbon electrode is completely covered thereby, and drying the glass carbon electrode in a drying device at room temperature to prepare the MWCNTs@UiO-66-NH2 composite material electrochemical sensor. The electrochemical sensor can achieve ultrasensitive detection on a sample. By an analysis method in the invention, an accurate analytic result can be acquired.

The invention relates to a making method and an application of a CdS sensitized TiO2 environmental estrogen photoelectrochemical sensor. The method uses TiO2 as an antigen capture substrate material, a CdS photoelectric active material is in situ generated on the surface of a Cd2<+> functional TiP nanomaterial maker modified electrode through a direct Na2S dropping technology, and CdS is irritated by an LED lamp of visible light wavelength to be converted to a photoelectric current signal. The substrate material TiO2 can be well matched with CdS energy band, so the photocurrent conversion signal of CdS is further improved, thereby the competitive photoelectrochemical immunosensor for ultra sensitive detection of estradiol, estriol, diethylstilbestrol, bisphenol A, nonylphenol, oestrone and other environmental pollutants is made.

The invention relates to a method of identifying illegal cooking oil by means of a Raman spectra technique and belongs to the technical field of food fast detection. The method comprises the following steps: measuring 2-5mL of edible oil needed to be detected, adding an extraction reagent A double in volume, whirling the mixture for 5-10min and then performing magnetic field assisted separation to extract natural capsaicin from the edible oil; then analyzing the extracted natural capsaicin by using 2-5mL of methanol to obtain a methanol extraction liquid; then adding the methanol extraction liquid into a derived solution B the same in volume, and performing a whirling reaction at room temperature for 1-3min; and finally adding an SERS enhancing reagent C the same in volume to the reaction solution, performing the whirling reaction at room temperature for 1-3min, and performing SERS detection; if characteristic peaks of natural capsaicin are shown in the SERS spectrogram, the detected edible oil is illegal cooking oil. The invention provides a simple, quick and super-sensitive analysis method for identifying illegal cooking oil, which has the characteristics of being distinct in target object, strong in characteristics, accurate in quality and simple in operation.

The invention discloses a TiO2 mesoscopic crystal based trypsin photoelectrochemical detection method. According to the method, a polyethylenimine(PEI)-sensitized TiO2 octahedral anatase mesoscopic crystal is utilized as a photoactive substrate material, and a signal amplification function on the substrate material by boron-doped carbon quantum dot labeling peptide (B-CODs@petide) is utilized to prepare a photoelectrochemical sensor to be applied to trypsin detection. Based on the stability and excellent conductivity of PEI, PEI and OAM can be compounded to accelerate the transfer rate of photo-generated electrons and improve photocurrent signals; through the introductions of B-CODs with the competitive light capturing ability and space hampered peptide chains, the photocurrent signals can be significantly reduced; when a modified electrode is incubated in a trypsin solution, trypsin can conduct catalytic hydrolysis on peptide bonds, and B-CODs@petide can be released from the surface of the electrode, so as to improve the photocurrent signals; the photocurrent signals and the trypsin concentration are linear in the range of 1*10<-7> to 1.0 mg/mL. The method can be used for monitoring screening of various proteases and inhibitors in early diagnoses of different diseases.

The invention relates to a method for preparing a sandwich type photoelectric chemical sensor for cardiac troponin I and belongs to the technical field of nano functional materials, immunoassay and photoelectrochemistry sensation. According to the method, a carboxylation CdS quantum dot is adopted to sensitize a 001 crystal surface of a nano square piece TiO2, then visible light absorption can beimproved, a composite material TiO2/CdS of which the photoelectric activity is remarkably improved is prepared, by using a layer-by-layer self-assembling method, a cardiac troponin I antibody, bovineserum albumin and cardiac troponin I antigen are assembled on the composite material TiO2/CdS, Ag@Cu2O shell-core nanoparticles are adopted as a second antibody marker, and by virtue of the excellentphotoelectric activity of the TiO2/CdS and specific combination of antigen and antibodies of the cardiac troponin I, super-sensitive detection on the cardiac troponin I can be achieved, and the methodhas great significances for analysis and detection on the cardiac troponin I.

The invention discloses a silver nanowire/molybdenum disulfide composite material surface enhanced Raman scattering substrate and a preparation method thereof, belongs to the technical field of detection, and is characterized in that the substrate is of a layered structure and sequentially comprises a silicon layer, a silicon dioxide layer, a triangular MoS2 layer and a metal silver nano-wire layer from bottom to top; the triangular MoS2 layer grows on the silicon dioxide layer through a chemical vapor deposition method, and the metal silver nano-wire layer is directly deposited on the triangular MoS2 layer. According to the surface-enhanced Raman scattering substrate, the silver nanowires are coupled to the molybdenum disulfide nanosheets to form a composite material, then Raman testing is conducted, and the SERS signal strength is improved from the aspect of electromagnetic enhancement through enhancement of a hot spot electric field at the interface between molybdenum disulfide andthe silver nanowires. The SERS substrate material is high in preparation repeatability and simple in step operation.

The invention relates to the technical field of biosensors, in particular to a fluorescent biosensor for detecting triphosadenine based on rolling circle amplification and incision enzyme feedback amplification. The biosensor comprises two aptamer DNA sequences, a linear padlock probe, a connecting probe, an AP probe, a T4 DNA ligase buffer solution, exonuclease I, exonuclease III, a PBS buffer solution, dNTP, phi29 DNA polymerase and endonuclease IV. A preparation method of the fluorescent biosensor comprises the following steps: (1) constructing an annular template to prepare a compound probe; and (2) combining a compound probe with an incision enzyme and a target object to achieve signal amplification. The probe can be used for achieving detection of high specificity and ultra-sensitivity. The fluorescent biosensor is mild in reaction, fast to detect and good in repeatability.

The invention relates to the technical field of biosensors, especially relates to a fluorescent biosensor based on hybrid chain reaction amplification, and solves the problems in the prior art that the method for detecting ampicillin is low in specificity and sensitivity, and the cost is high. According to a biosensor for detecting the ampicillin based on an aptamer, a cyclic amplification effectis realized by the cooperation of Nb.BbcCI and a chain hybrid chain reaction, and Thioflavine-T and G-quadruplex are combined to generate fluorescence and a homogeneous reaction mixed solution. The preparation method comprises the following steps of preparing gold nanoparticles; modifying Walker and Track to the surfaces of the gold nanoparticles; mixing a labeled nanogold solution with the homogeneous reaction solution; performing hyperbranched hybrid chain reaction and fluorescent detection; carrying out high specificity detection on the target ampicillin by using the aptamer by utilizing the specific recognition of the aptamer; and using hyperbranched hybrid chain reaction amplification to achieve signal amplification.

The invention belongs to the technical field of biomolecule detection, and discloses a circulating nucleic acid detection kit based on a microfluidic microsphere array chip and an application method thereof. The circulating nucleic acid detection kit based on the microfluidic microsphere array chip comprises a microfluidic detection chip for capturing probe functionalized microspheres, four LAMP primers and LAMP amplification reagents, a LAMP basic structure cyclization reagent and a cyclization auxiliary probe, a rolling ring amplification reagent, and a signal probe modified graphene quantumdot. The method is simple in operation and extremely high in sensitivity, and the early diagnosis of nasopharyngeal carcinoma can be achieved through detection of Epstein-Barr virus in blood. According to the circulating nucleic acid detection kit based on the microfluidic microsphere array chip and the application method thereof, the microscale and high-sensitivity detection characteristics of the micro-fluidic dynamic microarray chip, the multi-signal amplification (including loop-mediated isothermal amplification and rolling loop amplification) of the high-sensitivity target and the functional graphene quantum dot fluorescence signal amplification are integrated for the first time, and 10 mol/L Epstein-Barr virus DNA can be detected.

The invention relates to the technical field of biosensors, and particularly relates to a biosensor for detecting exosome based on a nucleic acid aptamer. The biosensor comprises an aptamer PTK-7 Apt,CD63 Apt, a connector, a hairpin probe H1, a hairpin probe H2 and a CCRF-CEM. The invention also relates to a production method and an application thereof. Based on specific recognition of the nucleic acid aptamer and a target object, through connection of the connector, two chains of PTK-7 Apt and CD63 Apt are adjacent to each other to form a trigger, and the trigger further opens H1 and the H1opens H2 to trigger an HCR reaction so that amplification of chemiluminescence intensity signals is realized, and the aptamer biosensor is constructed. The sensor has advantages of a high detection speed, simplicity in operation, a low price, a low detection limit, high specificity and the like.

The invention relates to the technical field of biosensors, and particularly relates to a fluorescent biosensor for detecting ochratoxin A based on a rolling ring amplification mediated catalytic hairpin self-assembly and incision enzyme feedback amplification method. According to the fluorescent biosensor, as for a detection mode, a fluorescence method is adopted for detection, and a luminoscopeis utilized; before detection, a padlock probe and a connecting probe form an annular template probe; then a target object is added to a homogeneous solution of a complex probe I, a complex probe II,HP 2 and HP 3, incubating is carried out for 120 minutes at 37 DEG C, and the target object and an aptamer sequence are bound; the multiple feedback amplification process is completed under the actionof a phi29 DNA polymerase and an endonuclease IV, so that signal amplification is realized; and then, the luminoscope is used for setting the excitation wavelength to be 399 nm, the fluorescence intensity at 610 nm is detected, and the detection range is 560-640 nm. Meanwhile, the invention further provides a preparation method for the biosensor. The preparation method has the advantages of beingmild in reaction condition and easy to operate.

The invention discloses a dual-signal-amplification fluorescence sensor for detecting mercury ions and a preparation method thereof. The fluorescence sensor comprises seven probes, namely a, b, c andd, namely a probe S, a probe F, a probe F1, a probe F2, a probe IP, a probe H1 and a probe H2; fuel stimulation isothermal amplification (FSP) primary circulation is realized based on specific recognition (T- Hg<2+> -T specific base mismatch) of the mercury ions and nucleic acid, an F2 chain released by the FSP can achieve chain displacement catalytic card assembly reaction (CHA) with H1 and H2, secondary circulation is achieved, and lastly the mercury ions are detected through fluorescence signal enhancement. The fluorescence sensor is advantaged in that the sensor has low detection limit, high sensitivity, high reaction speed, strong anti-interference capability, mild reaction conditions and the like, can make up for defects of a mercury ion detection method in the prior art, and realizes rapid and accurate quantitative detection of the mercury ions.

The invention relates to the technical field of biosensors and in particular relates to a colorimetric biosensor for detecting mercury ions and a preparation method thereof. The colorimetric biosensor is prepared from the preparation method comprising the following steps: synthesizing gold nanoparticles; modifying Probe4 on surfaces of the gold nanoparticles; mixing a marked nano gold solution and a homogeneous reaction solution. According to the colorimetric biosensor provided by the invention, high-specificity detection on the target object mercury ions is realized by utilizing specific recognition of an aptamer and a T-Hg<2+>-T composite structure; strand displacement is utilized and circulating utilization of Probe2 and Probe3 is realized and the effect of amplifying a signal is realized. The problems of a method for detecting the mercury ions at the prior art that the specificity and sensitivity are relatively low and the cost is high are solved.

The invention relates to a preparation method of an enzyme-linked immunosorbent assay kit for detecting an ovarian cancer tumor marker CA125 based on a trypsin fluorogenic substrate. An enzyme-linked immunosorbent assay technology and a fluorescent detection technology are combined to prepare a detection probe through trypsin and a tumor marker corresponding antibody Ab2; the probe, the tumor marker and another tumor marker antibody Ab1 embedded into the enzyme-linked immunosorbent assay (ELISA) kit can form a structure similar to a sandwich through the action between antigens of the antibodies; finally fluorescence is generated through the action between enzyme and the fluorescent substrate to qualitatively and quantitatively detect the ovarian cancer related tumor marker CA125, and a novel method for detecting protein markers is established. The preparation method has the characteristics that the whole preparation process is simple and suitable for industrial production; the protein markers can be qualitatively and quantitatively detected according to the fluorescent characteristics of the fluorogenic substrate and the action of the fluorogenic substrate with the enzyme, and the specificity is good; the whole detection process is low in cost and very convenient to operate; the novel method for detecting the protein markers is established.

The invention provides a porous membrane material for detecting phosphoinositide, and a preparation and detection method thereof. The porous membrane material comprises a porous membrane and a dual-component copolymer grafted to the channels of the porous membrane. The dual-component copolymer is grafted to channels of the porous membrane through the atom transfer free radical polymerization reaction mechanism. The detection method comprises the following steps: putting the porous membrane material between electrochemical cell clamps, injecting electrolyte, measuring the trans-membrane current (I0) under a preset voltage; removing the electrolyte, adding electrolyte containing phosphoinositide, measuring the trans-membrane current (I1) under the preset voltage; according to a formula (I0-I1)/I0, and calculating the value of changed current ratio under the preset voltage, wherein if the value is greater than 0.05, the sample contains phosphoinositide. The method of using provided porous membrane material to detect phosphoinositide has the advantages of high detection sensitivity, quick detection speed, simple operation, and low cost.

The invention relates to a super sensitivity fluorescence biosensor, for using magnetic practical to load antibodies and capture antigens, using water soluble conjugated polyelectrolyte to induce fluorescence amplification to check Escherichia coli O157: H7, which first utilizes magnetic particles to capture Escherichia coli O157: H7 antigens, to generate an antigen antibody unity with fluorescence labels; adds water soluble conjugated polyelectrolyte to induce and act with electrostatics, to recognize the super-molecules between the antigen antibody unity and the conjugated polyelectrolyte to form a super-molecule fluorescence composite system; exciting the fluorescence composite via the light or electricity of the conjugated polyelectrolyte, to induce the super fluorescence amplification of thousands and millions level of the prior fluorescence label signals, thereby forming a super sensitivity fluorescence biosensor. The biosensor system is based on the fluorescence sensitivity raising and efficiency raising effect of water soluble conjugated polyelectrolyte, which can be applied for fast super sensitivity detection on acute infectious disease as Escherichia coli O157: H7.

The invention discloses sialyloligosaccharide-magnetic nanoparticles as well as a preparation method and an application thereof. The general structural formula of the sialyloligosaccharide-magnetic nanoparticles is shown in formula X-1 or X-2. The sialyloligosaccharide-magnetic nanoparticles are prepared from alpha 2,3 sialyloligosaccharide and alpha 2,6 sialyloligosaccharide which are specifically bound with influenza virus HA protein by joining to magnetic nanoparticles through a covalent bond, the HA protein of type A influenza viruses of subtypes such as H1 and H5 and type A influenza virus strains of subtypes such as H1, H3, H5 and H7 are enriched and separated, and the receptor specificity of the influenza viruses is analyzed and detected. Accordingly, human influenza viruses and avian influenza viruses are selectively enriched, separated and purified, enrichment and separation or analysis of receptor specificity can be performed on samples with lower concentration and complex composition, and the sialyloligosaccharide-magnetic nanoparticles have quite good practicability and are of great significance in prevention and control of influenza viruses.