Nanoconfinement boosts electrochemiluminescence based on in-situ anchoring Pt NCs on mesoporous Mn₃O₄ for rapid and sensitive detection of salmonella typhimurium

The development of a simple, rapid and sensitive method for foodborne pathogens is essential to ensure public health safety. Existing methods, such as culture-based techniques and polymerase chain reaction (PCR), often face challenges in terms of time-consuming, labor-intensive, and require extensive sample preparation and amplification, which makes them impractical for rapid or on-site pathogen detection. Herein, a competitive mechanism-driven electrochemiluminescence (ECL) aptasensor was constructed for Salmonella typhimurium (S. typhimurium) detection without nucleic acid extraction and amplification. To boost the ECL signal of luminol-H₂O₂ systems, in-situ anchoring of Pt nanoclusters on mesoporous Mn₃O₄ nanoparticles (Pt NCs@M-Mn₃O₄) used as the nanoconfinement co-reactor. Benefitting from the restricted mesoporous structure, Pt NCs@M-Mn₃O₄ provided a unique microenvironment for the enrichment of H₂O₂. Furthermore, the interfacial interaction could activate the electronic transfer between active species of Pt NCs and M-Mn₃O₄, enabling a synergistic catalytic effect on ROS generation to effectively boost the ECL emission of luminol. The proposed ECL aptasensor had a linear concentration from 2 × 10¹ to 2 × 10⁶ CFU/mL with limit of detection of 8 CFU/mL of S. typhimurium. Furthermore, the method showed high anti-interference ability. Especially, satisfactory recovery values in spiked-actual samples were obtained, thereby demonstrating great potential for sensitive and reliable detection of S. typhimurium in various environments.