Nanometer-Flat DNA-Featured Thin Films Prepared via Laser Molecular Beam Deposition under High-Vacuum for Selective Methanol Sensing

We have developed nanometer-flat deoxyribonucleic acid (DNA)-featured solid thin films using a DNA source extracted from salmon sperm via laser molecular beam deposition (LMBD) under high-vacuum condition. The DNA thin films formed by LMBD had molecular flatness with an average surface roughness of 7.4 nm. Although fragmentation due to the cleavage of the phosphate bonds was observed, quartz crystal microbalance (QCM) sensors fabricated with DNA thin films using LMBD showed higher methanol detection capability than sensors using DNA thin films fabricated by spin coating, indicating that LMBD-DNA thin films have a high potential for sensor applications.