Fe<sub>3</sub>O<sub>4</sub>@Au Nanoparticle-Enabled Magnetic Separation Coupled with CRISPR/Cas12a for Ultrasensitive Detection of Foodborne Pathogens
Yiqing Guo, Wang Guo, Li Chen, Hong Xu, Xinai Zhang, Xiaobo Zou, Zongbao Sun
Abstract
The rapid detection of foodborne pathogens, such as Staphylococcus aureus and Salmonella, is critical for ensuring food safety. Herein, we present a magnetically controlled electrochemical biosensor integrating CRISPR/Cas12a with Fe 3 O 4 @Au nanoparticles designed to achieve ultrasensitive and multiplexed detection. By utilization of the magnetic separation of CRISPR-cleaved ssDNA from Fe 3 O 4 @Au nanoparticles, the sensor circumvents intricate electrode modifications, enabling direct signal readout. This approach expedites the workflow to 65 min while achieving a detection limit of 2 CFU/mL. Additionally, the sensor exhibits signal stability over 45 days and demonstrates its versatility by enabling the separate detection of both Gram-positive ( S. aureus ) and Gram-negative ( Salmonella ) pathogens. With validation in milk samples with high interference resistance, this platform bridges CRISPR programmability with practical deployability, offering a robust solution for on-site monitoring. The innovation lies in its simplified design, enhanced stability, and clinical versatility, setting a new benchmark for rapid, low-cost pathogen detection in resource-limited environments.