Gadolinium-doped hollow vesicle structure nanocomposite, and preparation and application thereof

The invention relates to a gadolinium-doped hollow vesicle structure nanocomposite. The nanocomposite uses a gadolinium-doped silica hollow vesicle as a main body; the surface of the main body is modified with a photosensitizer and polyethylene glycol with silane; in the main body, a ratio of the mole number of gadolinium to the mass of silica is (0.8 to 1.5) mmol: (80-120) mg; and a weight ratio of the main body to the photosensitizer to polyethylene glycol with silane is (40-50): (0.5-1.6): (30-50). Gadolinium acetate is used as an etching agent, solid silica microspheres are used as a silicon source and hard template, CO2 produced by acetate at high temperature is used as a soft template, and hollow vesicle microspheres are synthesized in one step; then the hollow vesicle microspheres are modified with the photosensitizer so as to allow the nanocomposite to have photodynamic and photo-thermal properties; and the nanocomposite is used for preparation of a contrast agent or a functional material with photody