Cathodic electrochemiluminescence of Eosin Y–peroxydisulfate system and its analytical application for determination of guanine

The cathodic electrochemiluminescence (ECL) behavior of Eosin Y (EY)–peroxydisulfate ( S 2 O 8 2 - ) system at a glassy carbon electrode (GCE) was studied under cyclic voltammetric conditions. Two strong ECL peaks, ECL-1 and ECL-2 were observed in cathodic and anodic scan process respectively under the potential scan range 0 to −2.0 V. The effects of pH value, S 2 O 8 2 - concentration on the ECL intensity were investigated and the possible mechanism for the ECL behavior of EY – S 2 O 8 2 - system was proposed. Based on the stable cathodic ECL of EY – S 2 O 8 2 - system and quenching effect of guanine on the ECL-1 and ECL-2 intensity simultaneously, the logarithmic plot of the inhibited ECL-1and ECL-2 versus logarithmic plot of the concentration of guanine was linear over the range of 5.0 × 10−6–1.0 × 10−4 mol/L with a correlation coefficient of 0.998 and 0.996, respectively.