36results about How to "Achieve high specificity detection" patented technology

The invention relates to a biosensor for detecting kanamycin based on target-induced conformational changes of nucleic acid aptamers. The invention is prepared by sequentially modifying an electrode with a HAP2 layer, a Helper layer, and a homogeneous reaction mixture. The present invention utilizes the specific type recognition of nucleic acid aptamer, uses the aptamer of kanamycin as the recognition substance to realize the highly specific detection of the target kanamycin; uses the nucleic acid tool enzyme to realize the recycling of the target , played the role of signal amplification, thereby improving the detection sensitivity.

The invention relates to the technical field of the biosensor and in particular to a biosensor for detecting kanamycin based on nucleic acid aptamer comformational change induced by a target object. The specific preparation method comprises the following steps: pre-processing an electrode; decorating an HAP2 layer on the surface of the electrode; and decorating homogeneous reaction mixed liquid on the surface of the electrode. The biosensor is capable of using the specific recognition of the nucleic acid aptamer, using the aptamer of the kanamycin as a recognition substance for high specific detection of the target object kanamycin, using nucleic acid tool enzyme, and realizing the cyclic utilization of the target object, and has the function of amplifying the signal.

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 provides a molecularly imprinted electrochemical sensor for detecting patulin. The sensor comprises a glassy carbon electrode, a thionine-Pt nanoparticle-nitrogen-doped graphene composite nanomaterial layer and a molecularly imprinted polymer layer. The molecularly imprinted electrochemical sensor can effectively amplify the signal, has high sensitivity and has good selectivity, a high recovery rate and good reproducibility. The molecularly imprinted electrochemical sensor is free of expensive large instruments, has a simple pretreatment process, ensures the accuracy of the results, realizes fast detection, greatly saves a cost and improves detection efficiency.

The invention provides a method for detecting salmonellae. The method comprises the following steps: synthesizing a DNA silver nano cluster; and carrying out index enlargement under the combined action of Phi 29 polymerase and Nt.AlwI endonuclease and homogeneous reaction of strand displacement cycle amplification, and then carrying out fluorescence detection. The method provided by the invention has the advantages that specific recognition of an aptamer is utilized, and the aptamer is designed into a hairpin structure, so that high specificity detection on a target object salmonellae is realized; and cyclic utilization of Trigger is realized by utilizing the combined action of the Phi 29 polymerase and Nt.AlwI endonuclease as well as strand displacement reaction, signal simplifying effect is achieved, and detection sensitivity is effectively improved.

The invention provides a method for detecting benzyl penicillin. The detection of the benzyl penicillin is realized in a homogeneous solution; amplification of a signal is realized in a two-step circulating manner, so that high-sensitivity detection of the benzyl penicillin is realized, and a relatively small lower detection limit is obtained.