Several anions, such as nitrates and phosphates, pollute water bodies and soils, as they are major constituents of fertilizers utilized in agriculture. It is therefore of interest to develop highly specific and sensitive methods of detecting these anions. Lanthanide ions in complexes, with their inherent long-lived luminescence, are excellent candidates for application as luminescent sensors. We have recently synthesized several ligands based on pyridinebis(oxazoline) (pybox) which sensitize lanthanide ion luminescence. We will present the photophysical characterization of complexes with the different pybox derivatives and how the emission behavior can be selectively influenced with different anions.