The invention relates to a polydopamine-coated nanometer composite photothermal
reagent and a preparation method thereof and belongs to the technical field of function materials. The method is simple to operate and two
coating methods are provided: firstly, inorganic nanometer particles or the surface of an
assembly of the inorganic nanometer particles are directly coated with a polydopamine shell layer through the oxidative
polymerization character of a
dopamine monomer; and secondly, nanometer particles are synthesized and coated by one step by utilizing the reducibility and the oxidative
polymerization character of
dopamine, so that the trouble of synthesizing the nanometer particles in advance is prevented, operation is more simple, and a synthesis method has better green
environmental protection character. Proved by experiments, after the nanometer particles are coated with the polydopamine shell layer, the
biocompatibility, the physiological environment stability and the photothermal stability of the nanometer particles are greatly improved; by introducing a hydroxyl functional group and an amino functional group, the condition of further modifying a biological targeting matter or a loaded
medicine is supplied for the nanometer particles; and in addition, as the polydopamine has the photothermal character, the
photothermal conversion efficiency of a material coated with the polydopamine shell layer is improved.