On-Site Nanowire Growth of Peptides Enables Stable Amine Selective QCM Gas Sensing

Here, we demonstrate a novel methodology for developing stable quartz crystal microbalance (QCM) gas sensors tightly decorated with self-assembled peptide nanowires as sensitive materials for the first time. When employing a conventional drop-casting method for decorating self-assembled peptide nanostructures onto a QCM electrode surface, observed sensor signals significantly exhibited background noise via unintentional energy dissipations. To overcome this inherent problem of depositing peptide self-assemblies, we developed an on-site growth method of peptide nanowires directly grown from a peptide amorphous film on a QCM electrode surface. The QCM sensors fabricated by the on-site growth method exhibited smaller background noise with lower energy dissipation, resulting in successful amine selective sensing. Thus, the present method using on-site growth will be a foundation to apply various functional peptide nanostructures to QCM gas sensors.