Rapid and sensitive identification of Pseudomonas aeruginosa through a fluorescent probe utilizing a magnetic 3D DNA walker and APE1 enzyme-powered cascade signal amplification

Abstract

The efficient and accurate identification of Pseudomonas aeruginosa (PA) is vital for reducing the risk of disease spread, and nucleic acid detection (NAT) is an excellent approach for the early diagnosis of this infectious agent. Herein, we created a fluorescent probe utilizing a magnetic 3D DNA walker that incorporates APE1 enzyme-driven signal enhancement (MDWAE) to quickly and precisely identify PA 16S rRNA. The DNA walker, activated by PA 16S rRNA, generates cleavage products that hybridize with molecular beacons containing apurinic sites, enabling APE1-mediated fluorescence amplification. This cascade process achieved PA determination within one hour with a detection limit of 1 CFU/mL while effectively differentiating PA from other bacteria. Recovery tests further confirmed that the cascade fluorescence probe is capable of detecting PA in spiked milk and orange juice samples, pointing to its potential for significant application in food safety assessments, environmental monitoring, and disease diagnosis.