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.

Keywords:

• Chemiluminescence
• G-quadruplex/hemin
• luminol
• hydrogen peroxide
• silver ions

Additional information

Funding

This work was supported by Anhui Provincial Natural Science Foundation (grant 201904a07020002) and the Anhui Provincial Department of Education (gxbjZD2021074).