Highly selective and sensitive fluorescence optode membrane for uranyl ion based on 5-(9-anthracenylmethyl)-5-aza-2,8-dithia[9],(2,9)-1,10-phenanthrolinophane

Abstract

A highly selective and sensitive fluorescent sensor for the determination of uranyl ion is developed. The sensing membrane was prepared by incorporating 5-(9-anthracenylmethyl)-5-aza-2,8-dithia[9],(2,9)-1,10-phenanthrolinophane as fluoroionophore in the plasticized poly(vinyl chloride) membrane containing 2-nitrophenyloctylether as plasticizer. The proposed sensor displays a wide linear response range of 1.0 × 10⁻¹⁰ to 1.0 × 10⁻³ M with a low limit of detection of 2.7 × 10⁻¹¹ M in solution at pH 4.0. This sensor has a relatively fast response time of less than three min. In addition to high stability and reproducibility, it shows a unique selectivity towards uranyl ion with respect to common coexisting cations. The sensor can be regenerated by exposure to a solution of ethylene diamine tetraacetic acid. The proposed sensor was then applied to the determination of uranyl in water samples with satisfactory results.