Our microporous thin-films can be cast on supports for a variety of gas and liquid sensor applications. Currently we are working with sensors to detect and quantify specific molecules and ions in aquatic environments. Our nanoporous thin-film metal oxide coatings can have very high specific surface areas on which potential-determining ions can adsorb to alter the surface potential at the solid solution interface.  Sub-micromolar (< 10-6 M) analyte concentrations can be detected. As part of our research, we are developing a sensor for orthophosphates using sol-gel materials, with experimental methods based in the electrochemistry of the interaction between phosphate and metal oxides.  Using electrochemical impedance spectroscopy, we have used nanoporous iron oxide thin-film electrodes to tie orthophosphate levels to experimental results, with sensitivity to nanomolar (10-9 M) phosphate in electrolyte solutions simulating lake water.