A Highly Selective Colorimetric Sensor for Cu2+Based on Phenolic Group Biscarbonyl Hydrazone

A novel copper selective sensor 2 based on hydrazide and salicylaldehyde has been designed and prepared. Sensor 2 behaves a single selectivity and sensitivity in the recognition for Cu2+ over other metal ions such as Fe3+, Hg2+, Ag+, Ca2+, Zn2+, Pb2+, Cd2+, Ni2+, Co2+, Cr3+ and Mg2+ in DMSO. The distinct color change and the rapid changement of fluorescence emission provide naked-eyes detection for Cu2+. The UV-vis data indicate that 1:2 stoichiometry complex is formed by sensor 2 and Cu2+. The association constant Ks was 3.51x104 mol1 center dot L. The detection limitation of Cu2+ with the sensor 2 was 2.2x107 mol center dot L1. The sensing of Cu2+ by this sensor was found to be reversible, with the Cu2+-induced color being lost upon addition of EDTA.