Dynamic detection of live female tea geometrid moths using an olfactory electrochemical impedance biosensor based on pheromone-binding protein

Abstract

Female tea geometrid moths release sex pheromones to attract male moths to mate, and then lay eggs on tea plants, which determines where the larvae hatch. The larvae preferred to devour the fresh leaves and buds of tea plants. Therefore, it is of great significance to dynamically monitor and detect the population of the female tea geometrid moths in tea plantations. Here, different from the common strategy of detecting male moths by sex pheromone lures, we developed an electrochemical impedance biosensor system based on the pheromone-binding protein 2 (PBP2) from male tea geometrid moths. It showed that this PBP2-biosensor could specifically bind two sex pheromone components at concentrations ranging from 10⁻⁷ to 10⁻⁴ ​M and successfully detect live female tea geometrid moths. Molecular docking prediction pinpointed key amino acids involved in the binding between PBP2 and sex pheromone components. Moreover, a mathematical model of the biosensor detection signal was developed based on the number of live moths and the dynamic detection data. The specific PBP2-based biosensor developed in this study not only offers a novel approach for detecting live female tea geometrid moths in the field, but also contributes to the advancement of insect olfactory biosensors for monitoring live pests and further expands the applications of biosystem engineering in the fields of plant protection and agricultural environment.