Study on Specific Apis cerana Honeybee Queen Pheromone Biosensor Based on Pheromone-Binding Protein ASP1

Biosensor is a detection device composed of a biologically active unit and a signal converter. In a eusocial honeybee colony, worker bees have also evolved a sophisticated olfactory system to specifically sense the queen pheromone components. So far, it is not clear whether it is possible to design a biosensor to detect the queen pheromone in vitro by using worker bees' olfactory system. In this study, a specific pheromone biosensor was successfully constructed by immobilizing the recombinant honeybees' pheromone binding protein 1 (PBP1/ASP1) on the forked finger gold electrode using nitrocellulose membrane. The results showed that the maximum resistance charge transfer (Rct) changes of two queen pheromone components [methyl p-hydroxy-benzoate (HOB) and vanillyl alcohol (HVA)] reached 60%, which were significantly higher than those of a bee larval pheromone component (ethyl oleate), and a floral volatile ($\beta $ -ionone). The linear detection of HOB and HVA ranged from 10 ^-7 to 10 ^-4 mol/L, and the theoretical detection limit reached 10 ^-8 mol/L, indicating the wide detection linear range and excellent detection capability of this biosensor. These results indicated that the biosensor was highly sensitive and specific to the queen pheromone components. It is beneficial to protect and maintain the sustainability of honeybee resources in the future.