Lanthanide recognition: A dysprosium(III) selective fluorimetric bulk optode

A fluorescence optical sensor for sensitive and selective determination of dysprosium(III) ions in aqueous solution has been prepared. The sensing system is made of 5-(dimethylamino)-N-(furan-2-yl-methylene)-naphthalene-1-sulfonohydrazide (L), as a neutral Dy3+-selective fluoroionophore, and a plasticized PVC membrane containing sodium tetraphenyl borate as a liphophilic anionic additive. The response of the optode is based on the strong fluorescence quenching of L by Dy3+ ions. At a pH of 5.0 the proposed sensor displays linear response in a rather wide concentration range of 1.0 × 10−10 to 1.0 × 10−2 M, with a fast response time of <35 s. Furthermore, the proposed optode displays a good selectivity toward Dy3+ ions in comparison with common coexisting cations. Also, it was applied successfully for determination of dysprosium ions in water samples.