An aminonaphthalene-based colorimetric and fluorescent sensor for selective recognition of Fe in water.

This paper describes the synthesis of poly(1-aminonaphthalene) and its application as a chemosensor for detection of Fe using the naked eye and a fluorimetric method. The conjugated polymer was synthesized by chemical oxidative polymerization using FeCl as a catalyst. The response of the polymer towards various metal ions was investigated using colorimetric detection, and ultraviolet-visible and fluorescence spectroscopies. The polymer displayed high selectivity and sensitivity towards Fe compared with other metal ions. A significant colour change from purple to yellow was observed upon addition of Fe by the naked eye. The polymer also showed a high selectivity and sensitivity 'turn-off' fluorescence response towards Fe ions. A good linear response was obtained for Fe concentrations in the range 10-50 mg L with a detection limit of 1.04 mg L . The proposed chemosensor was applied for determination of Fe content in water samples and satisfactory results were obtained.