AbstractMetallic nanoparticles have been extensively used to adsorb biomolecules and improve their stability under broader conditions. This study focuses on the interaction of Cytochrome C (CytC) and gold nanoparticles (AuNP), CytC@AuNP. Circular dichroism (CD) and Raman show significant differences in secondary structure, mainly in α‐helix. CD ramp temperatures revealed enhanced thermal stability of CytC@AuNP, as evidenced by a refolding of the α‐helix conformation of CytC and a delay in denaturation temperature by approximately 15 °C. Catalytic oxidation performed with CytC@AuNP showed a hyperbolic profile up to 104 % higher yields compared to CytC, which exhibited a linear profile and 30 % loss of activity after thermal treatment. The same reaction performed upon plasmon stimulus comparatively increased the catalytic yield of CytC@AuNP in 12 %, although it had no effect on free CytC. This study highlights the advantages of adsorbing biomolecules on nanoparticles and is a glimpse at plasmon‐driven nanobiocatalysis.