Design and construction of a novel optical sensor for determination of trace amounts of dysprosium ion

In this work, for the first time, a highly selective and sensitive dysprosium (Dy) optical sensor based on immobilization of N′-[(2-hydroxyphenyl)methylene] benzohydrazide (BBH) on a triacetylcellulose membrane was reported. This optode exhibits a linear range of 5.0 × 10−7 to 8.0 × 10−6 M of the Dy(III) ion concentration with a detection limit of 3.5 × 10−7 M. Response time of the newly designed optode was within 30–50 s, depending on the Dy(III) ion concentration. Response of the sensor is independent of the pH of the solution in the range of 3.0–5. The proposed optode shows low detection limit, fast response time, and most significantly, very good selectivity with respect to a number of lanthanide ions (La3+, Ce3+, Sm3+, Gd3+, Tm3+, Ho3+, and Eu3+ ions). The sensor was successfully regenerated with a thiourea solution and its response was reversible and reproducible (R.S.D. less than 1.6%). This optode was applied to the determination of Dy(III) in spiked sample.