Terahertz spectroscopy characterization of antibacterial surfaces prepared via multistep physicochemical procedure

The antibacterial surfaces presented can be one of the solutions for lowering the risk of pathogen outbreaks. Samples were prepared via a multistep physicochemical approach and characterized by terahertz spectroscopy. Properties of modified materials were analyzed using two spectrometers-terahertz pulsed imaging and spectroscopy Spectra [attenuated total reflection (ATR) and transmission module] and Tera optical sampling by cavity tuning. Each sample was measured 3 to 10 times to get accurate results. Observed regions for the transmittance module were set to 0 to 2.6 THz, and 0 to 4 THz for the ATR module. The obtained refractive indices allowed for easy distinguishing between each material. Absorbance spectra were assigned where possible as was the peak position that showed successful bonding of the used monomers/antibacterial agents. Measured dielectric properties described slight changes in materials due to the modification process. The experimentally analyzed transmittance displayed changes in every material up to the 2.6 THz region and Fabry-Perot interferences together with water vapor noise beyond this area. The section containing terahertz imaging of the samples is presented. The present work is one of the first of its kind. The possibility of using terahertz spectroscopy for characterizing materials with antibacterial agents bonded by intermolecular forces onto a treated surface is presented. (C) 2015 Society of Photo-Optical Instrumentation Engineers (SPIE)IGA grant at Tomas Bata University in Zlin [IGA/FAI/2014/001, IGA/FAI/2014/041]; European Regional Development Fund under the project CEBIA-Tech [CZ.1.05/2.1.00/03.0089]; Ministry of Education, Youth, and Sport of the Czech Republic under the project Centre of Polymer Systems [CZ.1.05/2.1.00/03.0111