Biofunctionalization Effectiveness of Titanium Oxide Thin Films Obtained with Physical and Chemical Vapour Deposition Methods for Optical Label-free Biosensing Applications

Abstract

An influence of titanium oxide (TiO_x) deposition method, i.e., chemical (atomic layer deposition, ALD) and physical (reactive magnetron sputtering, RMS) vapor deposition, on the optical properties and surface chemical modification were investigated. TheTiO_x film was used as a functional coating for enhancing sensing properties of two types of label-free optical sensors, i.e., localized surface plasmon resonance (LSPR) sensors based on gold nanoparticles and induced in optical fibre long-period gratings (LPGs) working in visible and infrared spectral range, respectively. We have found that independently on deposition method the films increase the sensitivity of LPG and enhance biofunctionalization capabilities.