A sensitive aptasensor for the detection of Vibrio parahaemolyticus

A simple and visual aptasensor has been established for the detection of the common seafood-borne pathogen Vibrio parahaemolyticus (V. parahaemolyticus). In this study, two specific aptamers were applied for V. parahaemolyticus enrichment. In the presence of the target, a "sandwich-type" complex of a-aptamer/target/c-aptamer/MBs was formed through specific recognition of the aptamer and corresponding target. Then, the cozmplex was used as template for strand displacement amplification (SDA), which combined with a lateral flow biosensor (SDA/LFB) to detect V. parahaemolyticus from pure cultures and spiked oyster homogenates. The entire process, including enrichment processing (20 min), SDA (30 min) and results (∼5 min), could be completed within 55 min. Under optimal conditions, the LOD of V. parahaemolyticus was as low as 10 cfu/ml by the naked eye and 5.6 cfu/ml by calculation for a pure culture. No cross-reactivity with other Vibrio species and non-Vibrio species was observed. Without the need for DNA extraction, the reduced handling and simpler equipment requirement render this assay suitable for the rapid screening of V. parahaemolyticus in clinical, food, and environmental samples.