This work describes the different characteristics of light absorption of hybrid magnetic nanoparticles when using different chelated metal ions or electroless deposited. Fe3O4@Agarose core-shell nanoparticles were modified to incorporate polydopamine (PDA) as a second shell. Fe3O4@Agarose-PDA nanoparticles make black solutions capable of absorbing a considerable amount of light. However, to make the nanoparticles more conductive, a metal can be deposited onto the surface of the particles. In this work, metal chelation and electroless deposition were proposed as a way to increase conductivity and change the absorption characteristics of the particles.
