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 (S2O82-) 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, S2O82- concentration on the ECL intensity were investigated and the possible mechanism for the ECL behavior of EY–S2O82- system was proposed. Based on the stable cathodic ECL of EY–S2O82- 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.

► We studied the cathodic ECL behavior of EY–S2O82- system at glassy carbon electrode.
► Two strong ECL peaks were observed in cathodic and anodic scan process respectively.
► The possible ECL mechanism was proposed.
► Guanine can quench the intensity of the two ECL peaks simultaneously.