Cardiac troponin I (cTnI) level in human blood is a key biomarker associated with acute myocardial infarction (AMI). Rapid, convenient, inexpensive and highly sensitive point-of-care (POC) bioassays for cTnI in home and community are of great importance in saving the lives of AMI patients. Herein, we present a three-stage amplified pressure-sensing bioassay system for highly sensitive detection of cTnI. Specifically, the magnetic bead-cTnI-Pt nanoclusters protein complex formed by the immunoconjugation of antigen and antibody can be conveniently subjected to magnetic separation to reduce background interference and achieve first-stage amplification. Then, the Pt nanoclusters in the complex can effectively catalyze the decomposition of H