Outer Surface Functionalized Graphene Oxide Nanofluidic Platform for Selective Detection of Insect Pheromones

Invasive insects inflict severe ecological and economic damage, creating an urgent need for rapid and early detection strategies. Here, we present a biomimetic strategy that replicates the molecular recognition principles of insect olfaction. As a proof of concept, our platform comprises a graphene oxide membrane with its outer surface functionalized with the pheromone-specific odorant-binding proteins (OBPs) of gypsy moth (Lymantria dispar). The OBP selectively captures the pheromone, (+)-disparlure (DIS), in the vapor phase. This binding event alters the outer surface charge of the nanochannel, which is directly transduced into a measurable change in ionic current─a mechanism that enables vapor-phase molecular recognition using solid-state nanochannels. The sensor detects DIS vapor with exceptional selectivity against nontarget volatiles and a limit of detection of ∼121.7 ppm. It maintains robust performance over 24 days of storage at 4 °C and operates reliably across a wide temperature range (4-60 °C). Crucially, it selectively identifies a single live female gypsy moth within minutes, with no cross-reactivity to other lepidopteran species. By translating the selective mechanism of insect olfaction into a synthetic nanofluidic architecture, this work establishes a versatile and generalizable strategy for proactive pest surveillance in agricultural fields, forests, and border inspection stations.