Towards a chip-based impedimetric biosensor for gaseous H202 detection

This paper presents a novel approach for the detection of hydrogen peroxide (H2O2) vapor at low concentrations and room temperature conditions, as these are often used for sterilization in medical industry. Interdigitated electrode structures (IDEs) have been fabricated on glass substrates by means of microfabrication techniques and Ti/Pt evaporation. Impedance spectroscopy is used for impedance measurements of the IDE structures in H2O2 atmosphere, which was provided by a glass bottle containing 20 mL of 35% w/w H2O2 (i.e., free evaporation in a confined space with stable and homogenous temperature). The sensor signal shows changes by varying the H2O2 concentrations inside the gas-tight glass bottle. Selectivity was achieved by means of the enzyme horse radish peroxidase. The detection of low concentrations of H2O2 gas at room temperature and in the aerosol phase is performed in this study for the first time, which paves the path towards on-line monitoring of H2O2 gas in aseptic processing.