High-entropy nanozymes integrated with CRISPR/Cas12a cascade amplification for highly sensitive point-of-care detection of cardiac troponin I.

Myocardial infarction necessitates rapid and ultrasensitive point-of-care detection of cardiac troponin I (cTnI). In this work, we develop a HEAzyme-enabled interfacial electrocatalytic transduction strategy integrated with CHA-CRISPR/Cas12a amplification framework for ultrasensitive electrochemical detection of cTnI. Capitalizing on the cocktail effect and carbon-shell confinement, HEAzyme amplifies the electrochemical response by catalyzing the redox reaction of surface-confined methylene blue. Target recognition initiates CHA, generating abundant DNA activators for Cas12a trans-cleavage. The synergistic integration of molecular cascade amplification and interfacial electrocatalysis enables a limit of detection of 0.21 fg/mL across a broad linear range from 1 fg/mL to 100 pg/mL. It exhibits good selectivity, maintains good stability within 7 days (RSD = 3.9%), and shows good batch-to-batch reproducibility in different batches (RSD = 3.44 and 5.8% for intra and inter-batch, respectively). This work establishes an effective strategy for integrating CRISPR-based molecular amplification with HEAzyme-enabled interfacial electrocatalytic transduction, providing a promising electrochemical platform for point-of-care diagnosis of myocardial infarction.