Described is a biodegradable and biocompatible hybrid nanoparticle for use in photothermal applications. The hybrid nanoparticle includes a poly(lactide-co-glycolic acid) core and a polydopamine shell. Optionally, the hybrid nanoparticle can be loaded with an active agent such as an anti-cancer agent. The hybrid nanoparticles can include detection agents, targeting agents, etc. The nanoparticles can be useful for disease detection, treatment, and monitoring.