Determination of glucose diffusion coefficient in biofilms with microelectrodes. Biosensors Bioelectronics 6:255–262

Abstract

Abstract: A glucose micro-electrode was developed for direct measurements inside biofiims, and applied for the determination of effective diffusion coefficients in a model system of agar beads containing immobilized yeast cells . Two methods were used, one based on concentration gradients present at the liquid/solid interface of an active biofilm under steady-state conditions, the other based on the rate of glucose redistribution in an inactivated biofilm under transient-state conditions . Additional measurements with pH and oxygen micro-electrodes were performed and thus allowed for in-situ correction of the glucose electrode signal . From the micro-electrode measurements in the model system it was concluded that the glucose micro-sensor is a useful tool with which to obtain effective diffusion coefficients in biofims