Detection of cyclohexane and xylene with insect odorant-binding protein-derived peptide receptors

The detection of volatile organic compounds (VOCs) associated with metabolic and pathological processes offers a promising route toward non-invasive disease diagnostics. Cyclohexane and xylene, classified as lung cancer biomarkers, lack selective bioreceptors for sensitive and selective detection. This article explores the potential of peptides derived from odorant-binding protein (OBP) of Aedes aegypti for the detection of cyclohexane and xylene, hydrocarbons relevant to breath analysis and environmental monitoring. Specifically, the modPep_17 sensor showed selective affinity to xylene with an LOD of 52.6 ppm, while modPep_25 was most responsive to cyclohexane with an LOD of 86.5 ppm, with concentration-dependent responses and approximately linear behavior within the three tested concentration levels. The novelty of this work lies in the use of insect-derived peptide sequences as recognition layers for the selective binding of chosen VOCs, a chemical group rarely addressed by biological receptors. This work explores insect-derived peptide sequences for VOCs sensing applications, providing a foundation for bioelectronic nose arrays targeting biomarkers. • Peptide-based QCM biosensors inspired by Aedes aegypti odorant-binding protein. • Selective detection of cyclohexane and xylene in the gas phase. • Peptides act as biologically derived recognition layers for non-polar VOCs. • Promising tool for breath analysis and non-invasive diagnostic applications.