A series of volatile organic compound (VOC) sensors has been developed for the detection of airborne semiochemicals emitted by invasive pests, including fall armyworm, cotton bollworm, and brown marmorated stink bug, which pose significant threats to European and Australian biosecurity. The sensors exhibit high sensitivity to pest pheromones in the vapour phase, with good tolerance to variations in humidity and temperature. By tailoring the molecular structures of the sensing materials, differentiated responses to target pheromones and interfering compounds were achieved, demonstrating the potential for selective, field-deployable pest detection using an electronic nose (e-nose) approach.
Invasive pests pose serious threats to global ecosystems, crop security, and agricultural economies.¹,² As a nondestructive monitoring strategy, sensing airborne semiochemicals using electronic noses has emerged as a promising approach for in situ detection of live pests. However, key challenges remain, including the extremely low concentrations of airborne semiochemicals and the need to discriminate pest species within chemically complex environments. These challenges and potential solutions have been discussed in a recent review.³
In this work, a series of new sensing materials (BS-01-A, BS-01-B, and BS-01-C), incorporating different functional moieties, were synthesised and deposited onto interdigitated electrodes. Sensor responses to synthetic semiochemicals in the vapour phase were calibrated over concentration ranges of 100 ppb–1000 ppb and 300 ppb–4 ppm, respectively (Figure 2a and 2b). Owing to differences in molecular functionality, the sensing materials exhibited distinct sensitivities toward the target semiochemicals, achieving limits of detection at the ppb level. The sensors also demonstrated good reversibility and satisfactory stability in ambient conditions. Selectivity studies showed stronger responses to target semiochemicals compared with common interfering VOCs, including alcohols, acetone, and hydrocarbons.