Long term stability of cantilever gas nanosensors to detect Euschistus heros (F.) pheromone release by rubber septa

Abstract

This work presents the use of cantilever gas nanosensors coated with PANI/PSS and PANI.Ag to monitor the release of neotropical brown stink bug, Euschistus heros (F.) pheromone in rubber septa (insect pheromone dispenser). The rubber septa was impregnated with the 2,6,10-methyl trimethyltridecanoate compound, the main component of the sexual pheromone of E. heros stink bug. Studies were conducted to detect and determine the pheromone release ratio under laboratory conditions during two months. Both cantilever nanosensors showed a daily reduction in resonance frequency when exposed to the rubber septum containing the pheromone, which was not observed in the control cantilever. The relative humidity did not presented influence on the nanosensors resonance frequency. The stability of the cantilever nanosensors was evaluated for 365 days (twelve months). Was observed a slight reduction of 1.4% in the resonance frequency for the nanosensor of PANI/PSS after 300 days of storage, and of 0.32% for the nanosensor PANI.Ag after 360 days. In this way, the gas nanosensors can be stored for long time presenting a long-term stable response and used successfully to detect the release of pheromone molecules.