All-in-one core-shell AuPt@PtCu/luminol nanozyme for glow-type chemiluminescence detection of Staphylococcus aureus

Conventional nanozyme-catalyzed chemiluminescence (CL) systems typically produce flash-type emission, which complicates reproducible quantification. Meanwhile, existing glow-type CL strategies rely on externally supplied luminol, which is typically physically mixed with the catalyst in solution, leaving the luminophore and catalytic centers spatially separated and compromising energy transfer efficiency. Herein, we constructed a core-shell nanozyme, AuPt@PtCu/Luminol (AuPt@PtCu/Lum), integrating the luminophore and catalytic centers within a single nanostructure. This structure endows the nanozyme with peroxidase- and catalase-like activities and intense glow-type CL with a plateau duration exceeding 1000 s in Na₂CO₃-NaHCO₃ buffer. On this basis, we established a label-free CL immunosensor for Staphylococcus aureus (S. aureus) detection, achieving a linear range of 2.5 × 10¹ to 2.5 × 10⁶ CFU mL^-1 and a limit of detection of 4.0 CFU mL^-1. Furthermore, the immunosensor demonstrated high accuracy and precision in spiked clinical specimens (urine and serum), indicating its practical applicability in real biological matrices. Overall, the integrated AuPt@PtCu/Lum-based glow-type CL immunosensor presents a robust tool for bacterial detection, holding great promise for clinical applications.