Olfactory biosensor based on odorant-binding proteins ofBactrocera dorsaliswith electrochemical impedance sensing for pest management

Abstract

Purpose Using the remarkable olfaction ability, insects can sense trace amounts of host plant volatiles that are notorious for causing severe damage to fruits and vegetables and in consequence the industry. The purpose of the paper is to investigate the interactions between olfactory proteins, odorant-binding proteins (OBPs) and host plant volatiles through the developed olfactory biosensors. It might be helpful to develop novel pest control strategies. Design/methodology/approach Using the successfully expressed and purified OBPs of the oriental fruit fly Bactrocera dorsalis, a biosensor was developed by immobilizing the proteins on interdigitated electrodes through nitrocellulose membrane. Based on electrochemical impedance sensing, benzaldehyde emitted by the host plants, such as Beta vulgaris, was detected, which could be used to investigate and analyze the mechanisms of pests’ sense of chemical signals. The relative decreases of charge transfer resistances of the sensor were proportional to the odorant concentrations from 10−7 M to 10−3 M. Meanwhile, the interactions between OBPs and benzaldehyde were studied through the process of molecular docking. Findings The paper provides a pest OBPs-based biosensor that could sensitively detect the host odorants benzaldehyde. Meanwhile, the most related amino acids of OBPs that bind to host plant volatiles can be distinguished with molecular docking. Originality/value An olfactory biosensor was developed to explore interactions and mechanism between the pest OBPs and benzaldehyde, which showed promising potentials for small organic molecule sensing. Simultaneously, it might be helpful for novel pest control strategies.

Molecularly Imprinted Polyscopoletin for the Electrochemical Detection of the Chronic Disease Marker Lysozyme

“…The relative variation of the charge transfer resistance for each sensor was calculated using the following equation: Rct−R 0 /R 0 where Rct is the charge transfer resistance recorded after the incubation of sensors in solutions containing Lyz, while R 0 is the initial resistance in absence of analyte. This parameter, known as “normalized impedance change” (NIC) [ 92 , 93 , 94 , 95 ], is often used as analytical signal in impedimetric measurements [ 96 , 97 , 98 ].…”

Equivalent circuit models for a biomembrane impedance sensor and analysis of electrochemical impedance spectra based on support vector regression

“…From an electrical point of view, the performance of an electrochemical cell can be represented by an equivalent circuit that has the same behavior and output with an equivalent input [22–24]. To study the equivalent model of the biomembrane impedance sensor, the equivalent model of the impedance sensor without a biomembrane (GE) needed to be first analyzed [25, 26]. According to the principles of electrochemical theory, the electrochemical reaction of a solution comprises two processes: the diffusion of ions from the solution to the interface of the electrode, i.e., the mass transfer process, and the ion reacting on the electrode, i.e., the activation process [6, 27, 28].…”

“…To simplify a complex system, such as electrodes in contact with different electrolytes, the model of the impedance sensor can be considered equivalent to the classical Randles model [25, 29, 30] (Fig. 3).…”

Tephritid Fruit Fly Semiochemicals: Current Knowledge and Future Perspectives

“…Thus, they are considered ideal candidates to be exploited in biosensors development and were used to engineer systems able to detect floral odorants, alcohols and explosives in Drosophila and Apis mellifera L. (Hymenoptera: Apidae) [ 531 , 532 , 533 , 534 ]. More recently, also a member of the Tephritidae family was target of this type of research: an OBP from B. dorsalis , BdorOBP2, was expressed, purified and immobilised on an interdigitated electrode and it was shown to work as an efficient biosensor for chemicals emitted by host plants (e.g., isoamyl acetate, β -ionone, benzaldehyde) [ 535 ]. As previously described, given their higher specificity and sensitivity ORs are ideal candidates to be explored for the development of biosensors.…”