Photocrosslinking nano hydrogel and preparation method thereof

The invention relates to a photocrosslinking nano hydrogel which comprises the effective component of an ultraviolet photo-initiated azido crosslinking carboxymethyl chitosan derivative, and is prepared by the method comprising the following steps: taking the water solution of carboxymethyl chitosan; adding the organic solution of 4-azidobenzaldehyde under the condition that the mol ratio of the sugar moiety of the carboxymethyl chitosan to the 4-azidobenzaldehyde is 1:(0.01-10); stirring and mixing evenly at 0-30 DEG C under the dark condition, wherein when a photocrosslinking carboxymethyl chitosan amphiphilic polymer is generated by the reaction, the amphiphilic polymer can be self-assembled into a photocrosslinking nano-particle mixed solution; and then radiating the nano-particle mixed solution by ultraviolet light to initiate azido crosslinking. The invention has simple process and easy operation, can obtain photocrosslinking targeted nano gel by coupling carboxyl with a target molecule or a target mole