A highly enhanced electrochemiluminescence system based on a novel Cu-MOF and its application in the determination of ferrous ion

A novel copper (II) metal-organic framework ([Cu(L)(H2O)(2)](n)Cu-MOF) has been successfully synthesized by facile one step hydrothermal method. Modified the glassy carbon electrode (GCE) with this kind of Cu-MOF, a strong cathode electrochemiluminescence (ECL) signal was produced under the potential scan from 0.2 to -1.6 V in the potassium persulfate solution, which was about 8 times higher than that on the bare GCE electrode. The possible enhancement mechanism was studied in detail. The results showed that Cu (II) in Cu-MOF catalyzed the reduction of potassium persulfate promoting the conversion of S2O82- into SO4 center dot- and enhancing ECL signal intensively. Based on the inhibition effect of ferrous ion on this ECL signal, a sensitive ECL method for the determination of ferrous ion was developed within the linear range from 1.0 x 10(-10) M to 3.0 x 10(-8) M and the detection limit of 4 x 10(-11) M. The ECL method showed high sensitivity, good stability, and excellent reproducibility and had been applied for analysis of ferrous ion in environmental water samples successfully.