2-(3-Hydroxy-naphthalen-2-yl)-benzo[d][1,3]oxazin-4-one (HNBO), 3-hydroxy-naphthalene-2-carboxylic acid (2-heptylcarbamoyl-phenyl)amide (HNAHPA) and 2-[2-(2-hydroxy-phenyl)-benzooxazol-6-ylmethylene]-malononitrile (HBODC) are shown to be fluorescent and colorimetric anion chemosensors with high selectivity for F- over Cl-, in the low analyte concentration range of 10(-6) to 10(-4) M. (c) 2007 Elsevier B.V. All rights reserved.