A novel integrated optical dissolved oxygen sensor for cell culture and micro total analysis systems

Production of accurate microscale oxygen sensors has been conventionally attempted using amperometric methods, which prove to be difficult to miniaturize, mainly due to the requirement of a bulky reference electrode. This paper details the design and fabrication process for an optically based oxygen sensor using an oxygen-sensitive fluorescent dye combined with microfabricated Cytop/spl trade/ waveguides that are monolithically integrated into the sensing substrate. Application of the dye to the optical waveguides was accomplished using a unique electrostatic layer-by-layer deposition process that has allowed us to deposit ultrathin dye layers to specific areas of the substrate. Testing of the oxygen sensitivity of the immobilized dye was carried out.