Determination of Hydrogen Peroxide and Silver Ions Using G-Quadruplex/Hemin Catalyzed Luminol Chemiluminescence

Abstract

G-quadruplex/hemin (GQH) is a mimicking enzyme, which has good catalytic performance and high stability for hydrogen peroxide decomposition. A new chemiluminescence (CL) method has been developed for H2O2 and Ag+ based on the GQH catalyzed CL reaction between luminol and H2O2. The silver ions react with GQH, causing the decomposition of GQH and the loss of catalytic activity. The catalytic system has been characterized by CL, absorption spectroscopy, and circular dichroism (CD). Under the optimal conditions, there were wide linear ranges between the CL intensity and the concentrations of H2O2/Ag+. The CL increases linearly from 0.1 μM to 3 mM for H2O2 and decreases linearly from 10 nM to 2 μM for Ag+. The limits of detection are 0.03 μM and 3.33 nM for H2O2 and Ag+, respectively. This method has been used for real sample analysis with satisfactory results.