Being a leading cause of death, heart diseases across the globe need special attention to enable early diagnosis. Metal nanoparticle-mediated biosensors are useful clinical tools for the early detection of bio-analytes. The size-dependent surface plasmon resonance (SPR) of metal nanoparticles can be effectively utilized for the same purpose. The early detection of heart diseases can be evaluated by monitoring the troponin level. A copper nanoparticle-mediated troponin biosensor was developed through antibody conjugation for troponin I and troponin T. The copper nanosensor shows a concentration-dependent SPR change towards troponin T and troponin I.