Characterization of biofilms with a fiber optic spectrometer

摘要

Optical sensing is one promising approach to monitor biofilms in an early stage. Generally, natural biofilms are quite inhomogeneous, therefore we start the investigation with suspensions of dead bacteria in water as a simple model for a biofilm. An experimental arrangement based on a white light fiber optic spectrometer is used for measuring the density of a thin film with a local resolution in the order of several mum. The method is applied with model biofilms. In a computer controlled procedure reflectance spectra may be recorded at different positions in the x-y plane. Scanning through thin suspension regions of bacteria between glass plates allows an estimation of the refractive index of bacteria. Taking advantage of the light collecting property of the glass substrate a simple measurement of the fluorescence with local resolution is demonstrated as well.