A scanning atmospheric radio-frequency (rf) plasma source was developed for surface decontamination and protective coating deposition. This plasma source was a dielectric barrier discharge system that utilizes a cylindrical electrode and a dielectric barrier surrounding the electrode. The gaseous species present in the plasma were analyzed with in-situ spectroscopic technique. Since the plasma generation region was open to ambient air, nitrogen, oxygen and water molecules in the air were readily excited. This system was used for decontamination of organophosphorus nerve agents and deposition of hydrophobic and superhydrophobic coatings on various substrates including ceramics, metals, fabrics, and nanofibers.