Nano chitosan derivative and preparation method and application thereof

The invention discloses a nano chitosan derivative and a preparation method thereof, belonging to the technical field of biomedical nano materials. The preparation method of the derivative comprises the following steps of: dissolving the chitosan in dilute acid and then mixing the chitosan with methacrylic acid epoxy propyl ester or acrylic acid epoxy propyl ester so as to conduct self-polymerization grafting reaction, thereby obtaining an intermediate with an active epoxy group, then leading the intermediate and an amino group to replace phenylboronic acid to carry out ring-opening addition reaction for finally obtaining the nano chitosan derivative with a boric acid active functional group, with the particle size of 1nm to 300nm. The invention also discloses the application of the chitosan derivative in the aspect of enriching and purifying glycosylated polypeptide/protein. The chitosan derivative has very high specificity, can be used for the enrichment and purification of low-abundance glycosylated polype