Method for preparing fluorescent magnetic nanoparticles with streptavidin combination function

The invention belongs to the technical field of nano materials and particularly relates to a method for preparing fluorescent magnetic nanoparticles with streptavidin combination function. The method comprises the following specific steps of: respectively connecting a Strep II label gene to N ends of alpha and beta sub-gene apoprotein genes to obtain Strep II-apcA and Strep II-apcB gene segments;embedding the Strep II-apcA gene segment to the downstream of a 6*His gene, and cloning to one expression vector together with a phycobilin biosynthetic enzyme gene; embedding the Strep II-apcB gene segment to the downstream of the 6*his gene, cloning to another vector together with a chromphore lyase gene, simultaneously converting the two expression vectors into escherichia coli, screening engineering bacteria, separating and purifying the engineering bacteria by protein, and oscillating and mixing the purified double-label recombinant APC fluorescent protein and zinc ion modified superparamagnetism silicon shell nanoparticles to obtain the fluorescent magnetic nanoparticles with the streptavidin combination function. The obtained double-label recombinant protein can biologically combine streptavidin without being modified chemically.