The invention relates to a nanometer carboxylated
polystyrene microsphere with a spacer arm and a preparation method thereof. A nanometer carboxylated
polystyrene microsphere A is prepared by taking
styrene and
acrylic acid as a mixed
monomer, taking water as a reaction medium, taking
potassium persulfate as an initiator and taking
sodium dodecyl sulfate as an emulsifier with an
emulsion polymerization method. In the presence of EDC (Ethylidene Dichloride) serving as a
coupling agent and Sulfo NHS, 4-
aminobutyric acid, 6-amidocaproic acid or 8-aminocaprylic acid is connected to the surface of the
microsphere, so that the nanometer carboxylated
polystyrene microsphere with the spacer arm is prepared. The spacer arm is introduced into the surface of the nanometer microsphere, so that the steric hindrance of a
coupling macromolecule is lowered, the activity and utilization ratio of the
macromolecule are increased, and a nonspecific interaction between the
macromolecule and the
polystyrene microsphere is reduced. Meanwhile, the grain
diameter of the microsphere can be adjusted by adjusting the using amount of the emulsifier, the length of the space arm and surface density, so that the nanometer microsphere has a wide application prospect in the fields of immune diagnosis,
solid phase extraction and the like when serving as a carrier as well as a template.