Lateral flow biosensor for DNA extraction-free detection of Salmonella based on aptamer mediated strand displacement amplification.

Abstract Convenient and sensitive point-of-care rapid diagnostic tests for food-borne pathogens have been a long-felt need of clinicians. Traditional approaches such as culture-based methods have good sensitivity and specificity, but they tend to be tedious and time-consuming. Herein we present a simple and sensitive aptamer based biosensor for rapid detection of Salmonella enteritidis ( S. enteritidis ). One of the aptamers specific for the outmembrane of S. enteritidis was used for magnetic bead enrichments. Another aptamer against S. enteritidis was used as a reporter for this pathogen, which was amplified by isothermal strand displacement amplification (SDA) and further detected by a lateral flow biosensor. As low as 10 1 colony forming unit (CFU) of S. enteritidis was detected in this study. Without DNA extraction, the reduced handling and simpler equipment requirement render this assay a simple and rapid alternative to conventional methods.