▎ 摘　　要

NOVELTY - Biosensor comprises up-conversion nanomaterial (UCNP) and graphene oxide (GO). The up-conversion nanomaterial is selected from nanoparticles. The particle size of up-conversion nanomaterial is 25-30nm. USE - Biosensor used in kit for detecting fumonisin B1 in food, such as corn, oat and its product (all claimed). ADVANTAGE - The biosensor provides an efficient, sensitive and convenient up-conversion fluorescent aptamer sensing technology to detect trace amounts of FB1 in food, and same time verifies that nucleic acid signal amplification strategy is efficiently applied to the field of food safety detection. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a kit for detecting fumonisin B1 comprises biosensor and FB1 standard; (2) a method for preparing a biosensor or kit by synthesizing magnetic microspheres (MMPs) and performing surface modification on it; synthesizing up-conversion nanomaterial and performing surface modification on it; and carrying out sub-packaging, packaging and/or preservation; and (3) a method for detecting fumonisin B1 by establishing a standard curve; detecting the sample to be tested; calculating concentration of FB1 in the sample to be tested according to the standard curve; connecting FB1 aptamer and its complementary DNA (cDNA) on the magnetic microspheres, catalytic hairpin self-assembly amplification caused by cDNA, ssDNA-UCNPs connection amplification product, and graphene oxide to quench the fluorescence of UCNPs.