Hermetia illucens (Diptera: Stratiomyidae) is a voracious scavenger insect with great capacity for bioconversion of organic waste. It can recognize and discriminate a wide range of chemical compounds that influence the choice of substrates for oviposition. Adult gravid females are attracted by VOCs from decomposing organic substrates and some species of bacteria present on decaying matter. The larval and adult transcriptome indicates an arsenal of odorant binding proteins (OBPs), that may facilitate the colonization of disparate environments with characteristic smells of decomposition. There is interest in development of sensing systems for malodours as often these indicate the presence of harmful components and can cause negative health and environmental effects. We report the expression, characterisation and performance of immobilised H. illucens OBPs (HillOBPs) on quartz crystal microbalance (QCM) transducers. The heterologous expression of recombinant HillOBPs was carried out with specific plasmids transformed in Escherichia coli BL21 (DE3) pLys and inoculated in 1 L of LB medium and four OBPs were expressed – HillOBP_C57, HillOBP_C11107, HillOBP_21691, HillOBP_C1173. Once delipidated and concentrated, HillOBPs were immobilized and used as biorecognition elements in quartz crystal microbalances (QCMs), to test the ability to detect volatile organic compounds (VOCs) of interest associated with organic decomposition. The resonant frequency changes of the QCMs were measured on exposure to various odorants. It was found that the HillOBPs-based biosensor array has a strong affinity for Isobutyraldehyde, Isovaleraldehyde, 2-Methylbutyraldehyde and Butyric acid at high and low concentrations in vapour phase. The performance of this HillOBP-based biosensor (high sensitivity, low limit of detection and good reversibility) may be of interest for the creation of fast, inexpensive and reliable malodour sensors for applications in environmental and agri-food monitoring.