Effect of amino compounds on luminol-H₂O₂-gold nanoparticle chemiluminescence system

In this work, the effect of amino compounds on the catalytic property of gold nanoparticles (AuNPs) in the luminol-H₂O₂ chemiluminescence (CL) system was systematically investigated. The experimental results showed that the catalytic ability of AuNPs on luminol-H₂O₂ system can be changed after AuNPs interacted with the amino compounds. It was found that two main aspects influence the catalytic property of AuNPs: (1) the electron density in conduction bands of AuNPs and (2) the surface negative charge density of AuNPs. Some amino compounds can decrease the electron density in the conduction bands of AuNPs after they reacted with AuNPs, resulting in a decrease of the catalytic property of AuNPs on luminol-H₂O₂ system. However, some amino compounds can cause AuNPs to aggregate after they reacted with AuNPs. The surface negative charge density of AuNPs would decrease, and zeta potentials were tested to verify the change of the surface negative charge density of AuNPs. As a result, the catalytic property of AuNPs on luminol-H₂O₂ system increased, and an enhanced CL signal can be obtained after the amino compounds reacted with AuNPs. This work will help people understand the catalytic mechanism of AuNPs and establish the CL method for the determination of amino compounds. Graphical Abstract Effects of amino compound on luminol-H₂O₂-AuNPs CL system.