A simple method to reduce optical cross-talk effects in chemical imaging with planar optodes

Abstract

A simple and universal method to minimize optical cross-talk in chemical imaging with planar optodes used for metabolic investigation of benthic interfaces is presented. Cross-talk can lead to smeared images and flattened gradients and therefore to erroneous analytical results. To minimize the cross-talk effect, an additional optical filter layer is coated on the downside of the transparent support. Cross-talk light traveling in the support and decoupled by scattering media is absorbed to a higher extent than the virtual signal. The extent of cross-talk and its reduction was evaluated by imaging the luminescence intensity of sensor layers with sharp edges and isolated points. The influence of cross-talk on the accuracy of oxygen determination by lifetime measurements was investigated by analyzing aerated and de-aerated zones of a planar optode placed on a scattering media. The presented method is compared qualitatively with methods previously described to reduce optical cross-talk effects. © 2012, by the American Society of Limnology and Oceanography, Inc.