Quantum Dot-Based F0F1-ATPase Aptasensor for Vibrio parahaemolyticus Detection

Sensitive detection of pathogenic bacteria is of great significance for food safety and public health. This study aimed to report a novel F0F1-ATPase aptasensor based on quantum dots (QDs) for quantitative detection of Vibrio parahaemolyticus. The fluorescent QDs were labeled onto the surface of chromatophores to act as an indicator. Aptamer target to V. parahaemolyticus was linked to the rotator epsilon-subunit of F0F1-ATPase within chromatophores to act as a recognition element. On the basis of aptamer and V. parahaemolyticus binding, the loading of epsilon-subunit was increased and the rotation rate of F0F1-ATPase was decreased, resulting in a decrease in the concentration of H+ out of the chromatophores. The increased pH value induced the increased fluorescence intensity of QDs. By using this fluorescent signal strategy in the detection, a limit of detection (LOD) as low as 7 cfu/mL was successfully achieved for ultrasensitive detection of V. parahaemolyticus. This aptasensing assay had no serious cross reaction with interfering species, and was successfully applied to the determination of V. parahaemolyticus in spiked shrimp and salmon samples. The F0F1-ATPase aptasensor provides a promising method for pathogenic bacteria detection in food safety and other application.