Biosensor electrode for detecting aspergillus flavus toxin B1 and method for making same

Abstract

The invention discloses a biosensor electrode for detecting aflatoxin B1 and a preparation method thereof. The biosensor electrode comprises a substrate layer and a reaction layer provided on the substrate layer. The reaction layer includes an electronic mediator, a sol-gel film and aflatoxin oxidase, wherein the electronic mediator is fixed on the substrate layer, and the sol-gel film embeds the aflatoxin oxidase on the substrate modified by the electronic mediator to form a film, thus obtaining aflatoxin oxidase modified electrode. The inventive biosensor electrode has the advantages of fast response, high signal sensitivity up to 1.5 ppm to 0.125 ppb, high specificity, convenient usage, quantitative detection, long service life and good stability.

Description

technical field [0001] The invention belongs to the field of biosensors, and relates to a method for detecting aflatoxin B 1 A biosensor electrode and a preparation method thereof. Background technique [0002] Aflatoxin B 1 (AF B 1 ) is one of the currently known strong carcinogens, which often contaminate animal feed and human food. In 1988, the International Agency for Research on Cancer (IARC) listed aflatoxin AFB1 as a human carcinogen. Feeding livestock with contaminated feed can lead to contamination of meat, milk and their products. If people eat contaminated food, it will cause acute poisoning, liver necrosis and hemorrhage, and chronic poisoning can cause liver cancer and lung cancer. At the same time, feeding poultry and livestock with contaminated feed will reduce the productivity of poultry and livestock, slow down the weight gain, and cause major economic losses. All countries have strict limits on aflatoxins in food and feed. [0003] At present, aflatox...

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Problems solved by technology

The TLC method is relatively simple and does not require expensive instruments and equipment, but the pretreatment of the sample is cumbersome, time-consuming, and has poor accuracy, and the use of a large amount of toxic organic solvents is harmful to the experimenters

[0004] The HPLC method requires high equipment costs, high technical level requirements, sample processing is still cumbersome, and the accuracy of the experimental results is easily affected by reagent differences, so it is not suitable for rapid detection; immunochemistry (enzyme-linked immunosorbent assay, including enzyme-linked immunosorbent assay, Radioimmunoassay, affinity chromatography): (1) Enzyme-linked immunosorbent assay, strong specificity, high sensitivity, low cost, suitable for batch detection, food and feed, however, the instability of the enzyme itself, complex samples Interference, the detection accuracy is not high; (2) radioimmunoassay, radioimmunoassay and enzyme immunoassay are similar, but radioimmunoassay storage radioactive contamination, has been eliminated; (3) affinity chromatography, developed in recent years Fast detection method, but expensive and difficult to promote

The reported enzyme biosensor method, such as Chinese patent ZL 200410028018.9 (another patent applied by the inventor of this patent), uses aflatoxin detoxification enzyme to prepare a sensor to detect aflatoxin B by covalently immobilizing it on the surface of a gold electrode 1 , the detection range is 1ppm ~ 10ppb, the detection sensitivity is not high enough

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