Deoxyribonucleic Acid Activator-Triggered Entropy-Driven Catalysis-Modulated CRISPR/Cas12a-Based Portable Biosensor for Simultaneous Detection of Multiple Pathogenic Bacteria

Rapid and sensitive detection of antibiotic-resistant bacteria (ARB) remains a critical challenge in clinical and public health settings. This study describes the successful construction of a portable DNA activator-triggered entropy-driven catalysis-modulated CRISPR/Cas12a-based sensor (PSDA) for the ultrasensitive and rapid detection of multiple ARB. This PSDA platform utilizes a CRISPR/Cas12a-mediated signal transduction strategy, in which a target-specific DNA activator initiates an entropy-driven dynamic DNA network for signal amplification. To further enhance detection performance, a 3D-printed microfluidic chip device with a smartphone-based readout system has been integrated into the sensor, using green-emitting Zn₂GeO₄:Mn persistent luminescent nanoparticles as a novel molecular beacon for fluorescence enhancement. This platform enables the simultaneous detection of methicillin-resistant Staphylococcus aureus, carbapenem-resistant Pseudomonas aeruginosa, and Klebsiella pneumoniae carbapenemase 2 (KPC-2)-expressing Klebsiella pneumoniae (KPC-2 KP) with a broad dynamic range (1-10⁷ CFU/mL), an ultralow detection limit (1 CFU/mL), and rapid analysis (∼45 min). The assay results are also highly consistent with those of conventional plate counting methods (95.48-115.15%). Overall, this study presents a cost-effective, rapid-response biosensing platform for the simultaneous detection of multiple ARB, with direct applications in clinical diagnostics, food safety monitoring, and environmental surveillance.