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

<p><span lang="EN-US" style="font-size:10pt;font-family:&#39;times new roman&#39; , serif;color:black">The
detection of volatile organic compounds (VOCs) associated with metabolic and
pathological processes offers a promising route toward non-invasive disease
diagnostics. The discovery and identification of reliable disease-specific VOCs
depend on consistent and accurate analysis of trace-level gaseous analytes,
particularly in breath samples. The natural diversity of olfactory systems and
their ability to bind gas molecules offer immense potential for incorporating
biological elements into biosensors for various applications, with a special
focus on healthcare and medical diagnostics. This article explores the
potential of peptides derived from odorant-binding protein (OBP) of <em>Aedes
aegypti</em> 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 good
linearity across the tested concentration range. The novelty of this work lies
in the use of insect-derived peptide sequences as recognition layers for the
selective binding of selected VOCs, a chemical group rarely addressed by
biological receptors.</span></p>