Fiber-optic microsensors to measure backscattered light intensity in biofilms

Abstract
We have constructed tapered fiber-optic microsensors with a tip diameter of less than 10 µm to measure profiles of backscattered light in biofilms, which are thin layers of micro-organisms firmly attached to surfaces. The observed response agrees well with local effective diffusivity microelectrode measurements, with R 2 > 0.85. A strong relation between signal intensity and wavelength has been observed at 670 and 1320 nm. These sensors have the potential to replace local effective diffusivity microelectrodes for true in situ biofilm measurements.