Nanosensors for Detecting Volatile Compounds in Pest Management: A Focus on Agricultural Sustainability

Traditional pest management strategies, such as indiscriminate pesticide use, have adverse environmental and human health implications. As a sustainable alternative, this research focuses on employing nanosensors for the detection of semiochemicals, including pheromones and defensive compounds, released by stink bugs. These nanosensors feature a nanohybrid layer of polyaniline and silver (PANI.Ag) and a nanocomposite of polyaniline and graphene oxide (PANI/GO). The study explores the detection of synthetic semiochemicals, including cis and trans bisabolene epoxides, (E)-2-hexanal, (E)-2-decenal, (E)-2-octenyl acetate, and (E)-2-octenal semiochemicals emitted by Nezara viridula (Southern green stink bug) in the real environment. The sensing layer characterization showed differences in hydrophilicity and surface roughness between the PANI.Ag and PANI/GO layers. When exposed to synthetic compounds like cis and trans bisabolene epoxides, (E)-2-hexanal, and (E)-2-decenal, the nanosensors demonstrated distinct responses, with PANI/GO exhibiting higher sensitivity. The resonance frequency shifts correlated with the concentration of the compounds, underscoring the potential of these sensors in detecting low concentrations with limits of detection (LOD) and quantification (LOQ) lower than 0.44 and 1.15 ng/mL, respectively. Real environment testing with soybean plants indicated that the nanosensors effectively detected semiochemicals emitted by N. viridula adults, especially in the presence of male–female couples, underscoring their potential for agricultural pest monitoring. The findings support the use of these nanosensors for the early detection of pest activity, offering a proactive approach to integrated pest management.