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

The invention discloses a signal-enhancement type immunochromatographic gold-labeled test strip and a preparation method thereof. The preparation method of the gold-labeled test strip comprises the following steps of: (1) combining colloidal gold nanometer particles with different particle diameters; (2) preparing a colloidal gold immunity detection probe; (3) preparing a colloidal gold signal enhancement probe; (4) mounting signal-enhancement type test paper; and (5) establishing a detection method of the signal-enhancement type test paper. The signal-enhancement type immunochromatographic gold-labeled test strip, disclosed by the invention, can be applied to field fast ultra-sensitive detection without needing other auxiliary instruments, and has the following advantages that: a detection operation can be finished within 10-15 minutes and a detection result can be obtained; the sensitivity of the traditional test paper detection method can be remarkably improved, and the ultra-sensitive detection of a low-concentration appointed target object which is not realized by the traditional test paper is realized; and as long as an antibody of the immunity identification probe of the test paper is correspondingly replaced, the detection of other target objects can be realized; the specificity is high, the stability is good, the application range is wide, the cost is low and the like; in addition, the signal-enhancement type immunochromatographic gold-labeled test strip and the preparation method thereof, disclosed by the invention, are easy to promote and apply.

The invention relates to a method for detecting multiple harmful substance residual components in food based on a surface plasma resonance (SPR) technique. The method comprises four steps of sensing surface aptamer fixing, sample marking, sample detecting and sensing element regenerating. The surface of a multi-probe optical fiber sensor is connected with the aptamer corresponding to different residual components; a molecular probe marker corresponding to different residual components is added and introduced on the sensing surface; unmarked and marked residual components carry out specificity competitive identification on the corresponding aptamer; molecular probe aptamer solution is introduced and combined with the marked sample connected on the surface of the optical fiber sensor for SPR detection by using the multi-probe optical fiber sensor; and the multi-probe optical fiber sensor can be used for regenerating to realize repeated use of the sensing element. Based on the SPR technique and the aptamer specificity competitive identification, multiple harmful substance residual components in one sample can be simultaneously detected, and the method provided by the invention is particularly suitable for detecting substances with small molecular weight.

The invention relates to the technical field of biological detection, in particular to a fluorescence biological detection method based on enzymatic remediation cycle three-time amplification. The method comprises steps as follows: an arched probe is constructed; enzymatic remediation cycle signal amplification and fluorescence detection are performed; high-specificity detection is performed on a target object, namely, salmonella, by the aid of a nucleic acid aptamer through specific recognition of the nucleic acid aptamer; the signal amplification effect is realized through enzymatic remediation cycle amplification.

The invention provides a preparation method of an electrochemical adapter sensor for detecting fumonisin B1 (FB1). The preparation method comprises the following steps of step one, preparation of an silk-printed carbon electrode (SPCE); step two, preparation of an activated FB1 aptamer solution; step three, preparation of an Au nanoparticles (AuNPs) modified SPCE; step four, preparation of an FB1 aptamer modified AuNPs-SPCE; step five, sealing of spare active sites on the surface of the electrode. According to the preparation method of the electrochemical adapter sensor for detecting the FB1, provided by the invention, the AuNPs are adopted for modifying the surface of the electrode, on one hand, the large amount of AuNPs are loaded on the surface of the electrode, so that a signal amplification function on label-free impedance method detection is obtained; on the other hand, more sulfhydrylated adapters are fixed to the surface of the electrode by utilizing Au-S bonds. An FB1 impedance detection method provided by the invention has the characteristics that the operation is more simple, convenient and flexible, instruments and equipment are simpler, the dosage of a reagent is less, the detection cost is low, and the like.

The invention belongs to the field of molecular imaging technologies, and discloses a pH (potential of hydrogen)-responsive type ultra-sensitive nanometer fluorescent probe and a method for preparingthe same. The pH-responsive type ultra-sensitive nanometer fluorescent probe comprises pH-responsive matrix materials and fluorescent organic small-molecule dye. The pH-responsive matrix materials comprise calcium phosphate, hydroxy calcium phosphate, fluorapatite, calcium carbonate and ZIF series; the fluorescent organic small-molecule dye is positively charged dye or negatively charged dye. Themethod includes coating the positively charged dye with the negatively charged matrix materials; coating the negatively charged dye with the negatively charged matrix materials; coating the negativelycharged dye with the positively charged matrix materials. The pH-responsive type ultra-sensitive nanometer fluorescent probe and the method have the advantages that the fluorescent imaging sensitivity and specificity can be greatly improved as compared with the traditional small-molecule fluorescent dye, and response of tumor micro-environments can be detected in an ultra-sensitive manner; the pH-responsive type ultra-sensitive nanometer fluorescent probe which is a specific responsive probe prepared for unique properties of the tumor micro-environments is high in targeting, few in backgroundsignals and high in signal-to-noise ratio, small tumor can be detected in an ultra-sensitive manner, and the like.