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The performance of nanozyme-based biosensing platforms is highly dependent on the composition and microenvironment of the active sites. Inspired by natural coordination environments, a biomimetic nanozyme was developed by incorporating L-glutamic acid (L-Glu) into a copper-imidazole framework (Cu-2MI). The amino acid modulates the copper active centers via coordination interactions, optimizing the local electronic structure and significantly enhancing peroxidase-like activity for efficient signal amplification. Based on this enhanced catalytic performance, an electrochemical aptasensor was constructed for ultrasensitive detection of cardiac troponin I (cTnI). The sensing interface was further engineered by in situ electrodeposition of gold nanoparticles (AuNPs) onto the Cu-2MI@L-Glu-modified electrode, followed by the immobilization of a cTnI-specific aptamer via Au-S bonds. The AuNPs layer significantly enhances interfacial conductivity and biocompatibility, ensuring efficient electron transfer and specific biorecognition. The captured cTnI forms a spatial obstruction that prevents H₂O₂ from accessing the active sites, thereby inhibiting the catalytic reaction. The constructed sensor demonstrates outstanding analytical performance: a wide linear range from 0.5 pg/mL to 300 ng/mL, a low detection limit of 0.16 pg/mL, and operational stability (> 85% response retention after 7 days). Its potential utility was assessed using spiked human serum samples, with satisfactory recovery rates (93% - 106%). By integrating biomimetic catalytic microenvironment design with rational interface engineering, this study provides a strategy for developing highly sensitive biosensing platforms and demonstrates significant potential for early diagnosis of cardiovascular diseases.