A Cationic Platinum Nanocluster-Based Loop-Mediated Isothermal Amplification Platform with Pretreatment by Magnetic Nanoparticles for Colorimetric and Quantitative Detection of MRSA from Clinical Samples.

Pathogenic bacteria are related to clinical infections and high morbidity, and they pose significant diagnostic challenges for rapid testing. Loop-mediated isothermal amplification (LAMP) is a fast, convenient, and highly sensitive nucleic acid assay but remains challenging in complex matrices as well as in strategies for fast and accurate result reading. In this study, a cationic platinum nanocluster-based loop-mediated isothermal amplification platform with pretreatment by magnetic nanoparticles was innovatively developed for the assay of methicillin-resistant Staphylococcus aureus (MRSA) in clinical samples. Concanavalin A-modified magnetic nanoparticles (ConA-MNPs) showed excellent separation performance and stability, with a capture efficiency (CE) >92% in HEPES. Meanwhile, we also innovatively combined nanozymes of cationic CS-PtNCs with LAMP to explore a new form of LAMP signaling output mode, enabling on-site, rapid readout of assay results. Furthermore, the excellent peroxidase-like activity of CS-PtNCs enables colorimetric signal output of LAMP results for accurate and quantitative detection of MRSA. The platform enables dual-mode detection (visual and colorimetric) of MRSA in clinical CSF samples in less than 1 hour, with a limit of detection (LOD) as low as 20 CFU per mL. In the future, this method is expected to enable field applications in clinical pathogen diagnosis and disease prevention, and could evolve into a universal detection platform by simply replacing components such as primers.