Electrochemical sensor for detection of europium based on poly-catechol and ion-imprinted sol-gel film modified screen-printed electrode

摘要

As a result of the increasing applications in different fields, europium has become a threat to the environment and human health. Thus, it is necessary to develop a simple and rapid method for determination of europium in trace level. In this paper, a sensor for determination of Eu3+ was established by modifying a screen printed electrode (SPE) successively with poly catechol as signal amplifying element and Eu(III) ion-imprinted membrane fabricated by sol-gel method as the recognition material. After the factors influenced the sensitivity of the sensor for Eu3+ was optimized in detail, Eu3+ can be determined by differential pulse adsorptive stripping voltammetry (DPASV) in the concentration range of 3.0 x 10(-7)-1.0 x 10(-3) mol L-1 with the detection limit of 1.0 x 10(similar to 7) mol L-1. The fabricated sensor owns outstanding selectivity, perfect stability and good regeneration. 50-fold excess concentration of rare earth ions such as Ce3+, Tb3+, Ho3+, Dy3+, Er3+, Gd3+, Pr3+, Nd3+, Yb3+ and 100-fold excess concentration of other metal ions such as Fe3+, Ni3+, Cu2+, Zn2+ and Co2+ have no influence on the determination of 1.0 x 10(-5) mol L-1 Eu3+. The obtained sensor, which can maintain 90% of its original response after used 60 times or stored in the water for 2 months, has been satisfactorily used to detect Eu3+ in water samples with the relative standard deviation (RSD) of 3.6% (n = 5) and recoveries in the range of 97.6%-101.6%.