A reusable optical sensing layer for picric acid based on the luminescence quenching of the Eu-thenoyltrifluoroacetone complex

A new luminescene sensing layer for the determination of picric acid based on reversible luminescence quenching of the Eu-thenoyltrifluoroacetone (TTA) complex was proposed. The optosensor was based on the electrostatic immobilization of the Eu-TTA complex on the chelating resin of Chelex 100 packed in the flow cell, which can induce a room temperature luminescence behaviour in an aqueous phase. The quenching mechanism was also studied. The detection limit was 2 X 10(-6) M by using a response time of 1 min. The optosensor was easy to prepare and the lifetime of the optosensor was at least 1 month. The optosensor has been used for the direct determination of picric acid in water samples and the indirect measurement of some drugs such as quinine.