14 results about "Thioflavin" patented technology

The invention discloses a label-free proportional type luminous aptamer biosensor for staphylococcus aureus enterotoxin A (SEA). The label-free proportional type luminous aptamer biosensor comprises the following steps: (1) advanced evolution screening of a complex matrix high-adaptability aptamer; (2) rationally cutting the aptamer assisted by computer simulation; (3) a construction strategy of the label-free proportional biosensor; (4) a label-free proportional SEA bifunctional biosensor sequence; (5) optimizing conditions of the label-free proportional SEA biosensor; and (6) SEA detection. The design principle is that fluorescence of SEA and ThT is excited to different degrees on the basis of a competitive binding effect between an SEA target and a small molecule nucleic acid dye thioflavin T (ThT) as well as a luminous nucleic acid aptamer, so that the ratio of fluorescence signals of the SEA and the ThT is in a linear relationship with the target concentration, and finally, rapid, label-free and low-cost proportional fluorescence detection of the SEA is realized.

The invention provides a system for ctDNA double-target detection based on a DNA functional nanomaterial and hydrogel and application, and relates to the technical field of biomedical diagnostic analysis, the system is used for executing the following analysis method, and the analysis method is to realize target specific recognition and trigger cascade signal amplification through the synergistic effect of DNA hydrogel and DNA coated Cu < 2 + > nanospheres. G-quadruplex exposed by DNA hydrogel can be efficiently combined with thioflavin T to generate enhanced fluorescence, and Cu < 2 + > released by DNA coated Cu < 2 + > nanospheres realizes dual-signal output by quenching quantum dot emission. Based on an advanced nano material and a signal amplification strategy, high-sensitivity, rapid and homogeneous ctDNA double-target detection is realized, sample separation operation is not needed in the whole detection process, and the almole-level detection limit can be reached within 40 minutes.

The invention discloses an application of an unmarked fluorescent aptamer sensor in endotoxin detection, according to an unmarked aptamer probe, a guanine-rich nucleic acid sequence is introduced to two ends of an endotoxin specific aptamer, the unmarked aptamer probe is combined with thioflavin T (ThT) to present a fluorescence'open 'state, when the endotoxin exists, the fluorescence is weakened, and when the endotoxin exists, the guanine-rich nucleic acid sequence is introduced to the two ends of the endotoxin specific aptamer, the guanine-rich nucleic acid sequence is introduced to the two ends of the thioflavin T (ThT); a linear relation exists between the fluorescence intensity change and the endotoxin content, and the method can be used for quantitative detection of endotoxin. Under the optimal condition, the linear range of the detector is 10-80 ng / mL, the limit of detection (LOD) is 3.26 ng / mL, the recovery rate in drinking water and fruit juice standard samples reaches 93.34-113.29%, and the relative deviation is 1.37-6.44%. The constructed non-labeled fluorescent aptamer sensor has the characteristics of strong specificity, high sensitivity and the like, and provides a promising solution for detecting endotoxin in a food sample.

A method for identifying a structural polymorphism of a fibrous protein or peptide, the method including the steps of: obtaining a fluorescence decay curve for a sample containing a fibrous protein or peptide and thioflavin T; performing exponential fitting of four or more components based on a specific function G(t) on a function F(t) of the fluorescence decay curve to obtain fluorescence lifetime values τ1 to τn and weighting factors A1 to An (n is a natural number of 4 or more) of the respective exponential components; and identifying the structural polymorphism of the fibrous protein or peptide based on at least one or more values of the fluorescence lifetime values τ1 to τn and at least one or more values of the weighting factors A1 to An (a fluorescence lifetime value and a weighting factor in an exponential component derived from autofluorescence of thioflavin T are excluded).

The application belongs to the technical field of biological analysis detection, and specifically discloses an acute myocardial infarction biological detection system based on multiplex isothermal transcription amplification, application and method thereof, the system comprises a probe group, PBCV-1 DNA ligase, T7 RNA polymerase and thioflavin T, the probe group comprises probes P1, P2, double-stranded probe P2 / A1 and double-stranded probe A2 / A3, the double-stranded probe A2 / A3 is composed of probe A2 and probe A3, and the double-stranded probe P2 / A1 is composed of probe P2 and probe A1. The application innovatively combines target recognition based on PBCV-1 DNA ligase, double-cycle transcription signal amplification mediated by T7 RNA polymerase and split G-quadruplex / ThT fluorescence signal amplification system, and constructs a triple signal cycle amplification detection system, which has the characteristics of ultra-high sensitivity, excellent specificity and simple operation.

The present invention discloses a method for visual inspection of tetrahydrocannabinol and its metabolites based on ratiometric fluorescence, which belongs to the field of biochemical detection technology. The method utilizes the specific binding ability of G-base-rich THC aptamers with thioflavin T and cresol violet, and realizes label-free ratiometric fluorescence detection analysis of the target THC through competition between the target THC and the two dyes thioflavin T and cresol violet. The method does not require chemical modification and only requires low-cost aptamers, thioflavin T and cresol violet dyes, and the three are stable and easy to preserve in practical applications. Rapid and visual detection of the target THC and its metabolites can be achieved through simple mixing. In the future, it is expected to be combined with a portable fluorescence detector to realize on-site instant detection of the target THC, providing a promising on-site detection strategy for tetrahydrocannabinol regulation. The selected THC aptamer is an oligonucleotide sequence obtained by in vitro screening, which has the advantages of high specificity, easy in vitro synthesis and stability.

To provide a method capable of easily and quickly identifying a structural polymorphism of a fibrous protein or a fibrous peptide.SOLUTION: A method for identifying a structural polymorphism of a fibrous protein or a fibrous peptide is provided, the method including the steps of: obtaining a fluorescence decay curve for a sample containing a fibrous protein or a fibrous peptide and thioflavin T; performing exponential fitting of four or more components based on a specific function G(t) on a function F(t) of the fluorescence decay curve to obtain fluorescence lifetime values τ1 to τn and weighting factors A1 to An (n is a natural number of 4 or more) of the respective exponential components; and identifying the structural polymorphism of the fibrous protein or the fibrous peptide on the basis of at least one or more values of the fluorescence lifetime values τ1 to τn and at least one or more values of the weighting factors A1 to An (a fluorescence lifetime value and a weighting factor in an exponential component derived from autofluorescence of thioflavin T are excluded).SELECTED DRAWING: None

The invention belongs to the technical field of biological analysis and detection, and particularly discloses an acute myocardial infarction biological detection system based on multiple isothermal transcription amplification and application and method thereof.The system comprises a probe set, PBCV-1 DNA ligase, T7 RNA polymerase and thioflavin T. The probe set comprises a probe P1, a probe P2, a double-stranded probe P2 / A1 and a double-stranded probe A2 / A3. The double-stranded probe A2 / A3 is formed by connecting a probe A2 and a probe A3, and the double-stranded probe P2 / A1 is formed by connecting a probe P2 and a probe A1. According to the application, target recognition based on PBCV-1 DNA ligase, T7 RNA polymerase mediated dual-cycle transcription signal amplification and a split G-quadruplex / ThT fluorescence signal amplification system are innovatively and organically combined to construct a triple signal cycle amplification detection system, and the triple signal cycle amplification detection system has the characteristics of ultrahigh sensitivity, excellent specificity, simplicity and convenience in operation and the like.

The invention belongs to the field of fluorescence sensors, relates to detection of tobramycin, and discloses a double-state probe switch type fluorescence sensor as well as a detection method and application thereof. According to the technology, quantitative analysis can be realized without enzyme catalysis or nucleic acid labeling through dynamic balance regulation and control of a G-quadruplex and thioflavin fluorescent system and CHA. The core mechanism is based on base pairing of Apt and cDNA: in the absence of TOB, Apt-cDNA forms a stable double-helix structure, so that HP2-5 rich in G bases spontaneously forms a G-quadruplex, and strong fluorescence is generated after ThT is embedded; according to the sensor, the CHA effect and G-quadruplex dynamic coordinated regulation and control are realized for the first time, complex steps such as enzyme catalysis and fluorescence labeling are not needed in an experiment, the sensor has low detection limit and high accuracy, can be accurately applied to actual sample detection, and a practical solution is provided for detection of TOB residues in animal-derived food.

The application belongs to the technical field of fluorescent probe detection, and particularly relates to a kind of blue fluorescent carbon quantum dots and its application. The application takes thioflavin T as raw material, ethanol as solvent, and synthesizes blue fluorescent carbon quantum dots with large conjugated structure through simple one-step microwave method. The carbon quantum dots are difficult to dissolve in water and easy to dissolve in organic solvents, and have sensitive fluorescence response to ethanol in the mixed solution of ethanol and water. Using the carbon quantum dots as fluorescent probe, the rapid and efficient detection of ethanol content in liquor can be realized by using ordinary fluorescence spectrometer, and the application has the advantages of convenient operation, high sensitivity, short response time and the like, and has broad application potential to develop portable alcohol detection scheme.

The invention belongs to the field of biosensors, and particularly relates to a label-free fluorescence resonance energy transfer (FRET) enhanced fluorescent histamine RNA biosensor. A histamine response type fluorescent RNA switch sequence is constructed, a histamine RNA aptamer and a Pepper fluorescent RNA aptamer are integrated into a whole through a connecting sequence, thioflavin T is introduced to serve as an energy donor, HBC530 serves as a receptor ligand, a label-free FRET pair is formed, the background is reduced, response is amplified, the signal-to-noise ratio is remarkably increased, and rapid, low-cost and fluorescent quantitative detection of histamine is achieved.

The application belongs to a kind of difluoroborane hydrazine pyrrole fluorescent probe and its preparation method and beta amyloid detection application, belongs to the field of fluorescence detection technology. The probe is composed of BOPHY fluorescent mother body and recognition group, and its preparation method includes three steps of BOPHY precursor preparation, fluorescent mother body synthesis and target probe molecule synthesis. The prepared series of probes have large Stokes shift, can effectively reduce imaging interference, and show high sensitivity and high selectivity of fluorescence response to A beta aggregate, wherein the performance of N-BOPHY is optimal. Experiments show that the binding affinity of the probe to A beta aggregate is high, the staining imaging result of A beta plaque in brain slice has high colocalization with commercial probe thioflavin-T, and the cell toxicity is low and the biocompatibility is good.

Provided herein are methods of determining a cognitive status of a test subject. In some embodiments, the methods include passing a test subject data set through a model that relates test subject data sets to cognitive status of the test subjects in which the model was created using reference subject data sets produced by determining three or more features from samples obtained from the reference subjects using at least a thioflavin T (ThT) assay, a dynamic light scattering (DLS) assay, and a neurotoxicity assay. In some embodiments, the methods also include outputting from the model a classification of the test subject as having a Parkinson's disease (PD) status of PD-NC (normal cognition) or PD-CI (cognitive impairment). Related systems, computer readable media, and additional methods are also provided.

The application discloses a hydrogel for improving the precision of photocuring 3D printing and application thereof. The application finds that the precision of photocuring 3D printing can be improved by adding a pigment such as thioflavin T, alizarin yellow R, methylene blue and / or purple cabbage into an ink containing a photo-crosslinking hydrogel such as methacrylated gelatin (GelMA) as a photocuring stabilizer. Based on this, the application provides a hydrogel ink capable of improving the precision of photocuring 3D printing, and by mixing the photo-crosslinking hydrogel with a photo initiator and a photocuring stabilizer in proportion, the entity obtained by printing using the hydrogel ink has higher precision. In addition, the operation of 3D printing using the hydrogel ink is simple, has strong practicability, and is beneficial to the construction of repair materials required in the biomedical field such as tissue engineering.