Photoacoustic absorption spectra of biofilms

Biofilms are aggregates of microorganisms which occur at the interfaces of natural and engineered aqueous systems. In this article, the use of photoacoustic spectroscopy (PAS) as a new technique for online and in situ monitoring of biofilms is demonstrated. Former studies revealed that PAS allows the monitoring of growth, detachment, and thickness of biofilms. Here, first photoacoustic absorption spectra of biofilms in the visible and near infrared range and corresponding depth-resolved measurements are presented.