Novel bioorthogonal reaction-mediated particle counting sensing platform using phage for rapid detection of...

Bacterial detection in foods have to overcome the hindrance of complex matrices, resulting in more sophisticated pre-treatment steps and low sensitivity and reproductivity. Therefore, it remains a challenge to develop simple, rapid, accurate, and low-cost pathogen detection methods which were applicable for detection in turbid or complex food matrices. In this study, a novel bioorthogonal reaction-amplified microparticle counting sensing based on phages has been developed for the rapid detection of viable Salmonella in different foods. Phage not only acted as a bioreceptor to recognize viable Salmonella, but also used as an effective carrier for signal amplifiers due to its large specific surface area. The bioorthogonal reaction was introduced to further amplify the signal, the presence of Salmonella can specifically induce a quantitative change in the functionalized polystyrene microspheres, and thus can be monitored by the microporous resistance particle counter. Under the optimized conditions, this sensor could achieve a limit of detection of 33.58 CFU/mL and a linear range from 10² CFU/mL to 10⁶ CFU/mL. This phage-mediated microporous resistance particle sensor can specifically recognize viable Salmonella in 1 h, providing a powerful platform for rapid and low-cost Salmonella quantification.