Dual excitation orthogonal emission upconversion luminescent nanoparticles, multi-throughput detection immunochromatographic test strips and their applications

Abstract

The invention discloses a dual-excitation orthogonal emission up-conversion luminescent nanoparticle, which is characterized in that it is a dual-excitation orthogonal emission up-conversion luminescent nanoparticle having a core-shell structure with two outer shells, which is doped with NaYF of Yb, Tm and Er 4 Nanoparticles as cores with Yb-doped NaYF 4 Form the first shell layer with Yb, Nd doped NaYF 4 Formation of the second shell, constituting NaYF co-doped with Yb, Tm, Er and Nd 4 :Yb / Tm / Er@NaYF 4 :Yb@NaYF 4 : Yb / Nd core-shell nanoparticle structure; the antigen of the detection object is labeled on the surface of the nanoparticle, which emits red light under the excitation of the laser with a wavelength of 980 nm in the near-infrared light, and emits green light under the excitation of the laser with a wavelength of 808 nm. The invention also discloses a multi-flux detection immunochromatographic test paper using the nanoparticle and its application. The invention greatly simplifies the detection operation steps through the simultaneous improvement of the nanoparticle material, the test paper and the detection method, has low cost and high detection sensitivity, and can realize multi-throughput, rapid, qualitative and quantitative detection of food.

Description

technical field [0001] The invention belongs to the technical field of biomedical diagnostic materials and detection, in particular to a dual excitation orthogonal emission up-conversion luminescent nanoparticle, a multi-flux detection immunochromatographic test paper and its application. Background technique [0002] Among the most important problems affecting the quality and safety of grain and oil in the world, the problem of grain and oil products being contaminated by mycotoxins, heavy metals and pesticide residues is the most serious. According to the United Nations Food and Agriculture Organization (FAO) statistics, 25% of the world's food is contaminated with mycotoxins such as aflatoxins, and the loss of mildew is 1.5%-3% of the total output. Aflatoxin B1 is an important toxic mycotoxin that is always produced during grain growth and storage. Ingestion of AFB1 may cause serious diseases, such as acute liver cirrhosis, cell necrosis and carcinogenesis. Therefore, the...

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Problems solved by technology

[0004] Accurate results and statutory approval are the biggest advantages of physical and chemical methods, but the equipment is expensive, the pretreatment process is complicated, the operation is cumbersome, the efficiency is low, and the cost is extremely high, so it is not suitable for large-scale sample screening and daily internal control testing. For final confirmation only

Enzyme-linked immunosorbent assay (ELISA) method and colloidal gold rapid detection card are commonly used rapid detection methods in enterprises, but both have their own advantages and disadvantages: ELISA method has relatively high sensitivity and quantitative detection, but the operation process is relatively complicated. The environment and personnel requirements are high, the environmental interference factors are complex, and the repeatability is poor; the traditional colloidal gold detection card can meet the rapid on-site requirements, and can be quickly measured within 5-10 minutes, but it can only be qualitative, and the sensitivity is low, and the naked eye is subjective. Strong reproducibility, poor reproducibility, and requires multiple antibody-modified AuNPs to be evenly immobilized on the same binding pad, which will lead to cross-reactivity between different AuNPs and test lines, and reduce detection accuracy

However, in actual application, the inventor found that the colloidal gold chromatography test strip can only detect the composition and concentration of one substance to be detected at a time, which cannot meet the rapid detection requirements for multiple substances in food, and is not suitable for use. The equipment performs automatic and multi-throughput detection, so it has the problems of slow detection speed and low efficiency, and further improvement is needed

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