Portable visual platform integrates polymerase spiral amplification and CRISPR/Cas12a for foodborne bacteria point-of-care testing

Staphylococcus aureus, a prominent global foodborne pathogen, frequently triggers epidemics with severe public health impacts. Timely and reliable detection of S. aureus is crucial for mitigating the disease burden in low- and middle-income countries. However, conventional laboratory-based detection methods remain impractical in resource-limited settings, highlighting the urgent need for accessible point-of-care solutions. Here, we present an inner-outer-tube (IOT) assay that synergistically integrates the polymerase spiral amplification (PSR) technology for enhanced sensitivity with the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 12a (Cas12a) system for sequence-specific identification. Additionally, we have created a portable all-in-one mobile detection (PAMD) device that combines all the steps needed for testing in the field, allowing for quick visual detection of S. aureus in just 60 min. The PSR-CRISPR/Cas12a-IOT method implemented with the PAMD device achieves a detection limit of 10 cfu/mL without needing extra preparation or costly equipment. The detection platform developed in this work has advantages of ease of operation, manageable costs, and robust performance, making it highly ideal for low-resource contexts and on-site detection scenarios. Furthermore, the PSR-CRISPR/Cas12a-IOT-PAMD detection platform provides global versatility through the interchangeable use of primer sets, hence broadening its applicability to various infections.