7 results about "Staphylococcus aureus enterotoxin" patented technology

This invention belongs to the field of immunological testing and discloses nanobodies, antibody compositions, and their applications for detecting Staphylococcus aureus enterotoxin H. The invention successfully screened for Staphylococcus aureus enterotoxin H-specific antibodies and used a checkerboard titration method to identify capture antibodies, AntiSEH-Nb4, and detection antibodies, AntiSEH-Nb3. The resulting antibodies are effective for detecting food poisoning caused by non-classical enterotoxin H, providing a highly specific means of detecting Staphylococcus aureus enterotoxin H. This not only improves the accuracy and reliability of detection but also facilitates the rapid diagnosis and prevention of outbreaks of related foodborne diseases.

The invention provides a staphylococcus aureus nanocrystallization antigen, a vaccine containing the staphylococcus aureus nanocrystallization antigen and application of the staphylococcus aureus nanocrystallization antigen. The staphylococcus aureus nanocrystallization antigen is obtained by modifying a staphylococcus aureus antigen through a nanocrystallization matrix, and the nanocrystallization matrix is one or more of streptococcus pneumoniae capsular polysaccharide, staphylococcus aureus capsular polysaccharide and sodium hyaluronate; the staphylococcus aureus antigen is one or more of staphylococcus aureus enterotoxin A, staphylococcus aureus enterotoxin B, staphylococcus aureus enterotoxin C2 and toxic shock toxin syndrome toxin 1. The staphylococcus aureus nanocrystallization antigen and the vaccine containing the staphylococcus aureus nanocrystallization antigen can induce high-level immune response, the antibody durability is high, the dosage of the used antigen is low, and the safety is good; and the preparation method is simple, high in production efficiency and low in cost.

The invention belongs to the technical field of biosensors, and discloses a photoelectrochemical immunosensor based on a dendritic peptide tetramer as well as a preparation method and application of the photoelectrochemical immunosensor. The dendritic peptide tetramer is adopted to construct the photoelectrochemical immunosensor for the first time, and the method comprises the following steps: preparing an HsGDY / Cu2O photocathode, and sequentially anchoring an antibody probe and the dendritic peptide tetramer on the surface of the photocathode. Through specific binding of a target object and the antibody probe, a significant steric hindrance effect is generated on an electrode interface, interface charge transfer is hindered, photocurrent signal change is caused, and detection of the target object staphylococcus aureus enterotoxin A is realized. The photoelectrochemical immunosensor provided by the invention is simple, convenient and efficient in preparation process, has excellent food matrix biological pollution resistance, can effectively inhibit non-specific adsorption so as to significantly improve the sensitivity, specificity and accuracy of detection, is suitable for the field of food safety detection, and is suitable for market popularization and application.

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 present application relates to a kind of high-throughput staphylococcus aureus enterotoxin microfluidic chip detection method and application based on chain quantity amplification enhanced fluorescence.The microfluidic chip is provided with fluorescence sensor, and the fluorescence sensor includes identification probe and signal probe;The identification probe is composed of magnetic nanoparticle, nucleic acid aptamer H1 of target to be measured and target aptamer complementary chain H2, and the signal probe is composed of nanomaterial with signal amplification function and three oligonucleotides H3, H4, H5.The present application combines MNPs-ssDNA-AuNPs sandwich structure system and microfluidic chip, realizes detection signal amplification using the excellent superparamagnetic property of MNPs and the high loading capacity of AuNPs, constructs high-throughput, high-sensitivity fluorescence sensing technology for SEA, SEB and SEC1 detection, simplifies experimental process, and builds the rapid, efficient detection platform of multiple pollutants in food.

The invention provides a universal purification method of a recombinant staphylococcus aureus protein antigen. The purification method comprises the steps of sample treatment and refined purification. Wherein the sample treatment comprises fermentation material liquid crushing, crushed sample clarification and clarified sample concentration; the fine purification comprises primary purification, medium purification and fine purification; the recombinant staphylococcus aureus protein antigen is recombinant staphylococcus aureus enterotoxin A, enterotoxin B, enterotoxin C2 and / or toxic shock syndrome toxin 1. The purification method meets the quality standard required by pharmacopeia, also has the advantages of high yield, simple process, easy amplification and low cost, and greatly simplifies the production and preparation work of the recombinant staphylococcus aureus enterotoxin A, enterotoxin B, enterotoxin C2 and toxic shock syndrome toxin 1.

This invention discloses a biosensor and electrochemical detection method for detecting Staphylococcus aureus enterotoxin A (SEA). The biosensor includes an electrode modified with an MXene / AuNPs nanocomposite material, a recognition probe complex, a signal probe complex, and a capture probe. This invention increases the electrode's conductivity and specific surface area by modifying the electrode surface with the MXene / AuNPs complex. Simultaneously, it introduces a chain substitution reaction signal amplification strategy, achieving efficient amplification of the electrochemical signal and significantly improving detection sensitivity. This sensor combines the excellent properties of nanomaterials with a nucleic acid signal amplification strategy, exhibiting good specificity, stability, and repeatability in SEA detection. Furthermore, this sensor requires no complex pretreatment, has a rapid response, and shows great potential for detection in practical food samples.