The manipulation of nanocomposites in conjunction with biomolecules is crucial for the development of novel bio-conjugates for applications in nanomedicine. These so-called “theranostic” materials represent the state-of-the-art in the use of hybrid nanocomposites for cancer diagnosis and therapy, due to their ability of targeting specific tissues and cells. Due to their ease of preparation and functionalization, graphene oxides and gold nanorods (AuNRs), in particular, have found applications as theranostic agents for cancer therapy. These materials exhibit an absorption band in the near infrared region – where the maximum radiation penetration through tissues occurs-, which makes them appropriate for in vivo photothermal applications. In this talk we will focus on the synthesis and application of hybrid nanocomposites based upon AuNRs coated with cancer cell membranes, used as active agents in photohyperthermia. Glutamine-covered graphene oxide nanocomplexes were also synthesized and applied in the hyperthermia studies. The incorporation of gold nanorods into real membrane monolayers was also studied using Langmuir techniques. The use of cancer cell membrane-coated nanoparticles opens up new possibilities regarding the development of efficient theranostic nanosystems and brings benefits to the field of personalized medicines. The toxicity exhibited by the nanocomplexes against healthy human cells and aquatic organisms will also be addressed.