Bio-inspired sensor for insect pheromone analysis based on polyaniline functionalized AFM cantilever sensor

Bio-inspired materials designed for mimicking nature has gained attention in the last years, owing to their appealing properties, such as adhesive and self-cleaning properties. However, studies reporting bio-inspired sensors able to detect minimal amounts of pheromones are still scarce. Here we report on the functionalization of AFM cantilever with polyaniline (PANI), which was used as a sensor to detect pheromone 2-heptanone. This hormone is very significant for honey bees, which release it as a repellent scent marking to avoid enemies and other bees. The functionalization of the sensor was achieved by depositing a thin film of PANI in the emeraldine state on the cantilever through spin-coating. Infrared spectroscopy showed that the 2-heptanone was adsorbed by PANI film deposited on cantilever surface. The linear response of the coated cantilever sensor regarding 2-heptanone concentration for distinct temperatures was evaluated, as well as its mechanical behavior, hysteresis and storage time. The approach proposed here to functionalize AFM cantilever with PANI film to detect 2-heptanone showed a potential methodology for designing sensors able to detect minimal amounts of pheromones and natural compounds.