Aminothiols Sensing Based on Fluorosurfactant-Mediated Triangular Gold Nanoparticle-Catalyzed Luminol Chemiluminescence

Abstract

A novel method was used to synthesize triangular gold nanoparticles (AuNPs) (i.e., trisodium citrate reduction of HAuCl4 in the presence of nonionic fluorosurfactant). The as-prepared triangular AuNPs owned higher surface-to-volume ratio and more active surface sites compared to spherical AuNPs, which facilitated the active oxygen intermediates generation and electron-transfer processes on the surface of triangular AuNPs. Therefore, it was first found that triangular AuNPs displayed greater catalytic activity (ca. 125-fold) toward luminol chemiluminescence (CL) than spherical AuNPs. More interestingly, ultratrace aminothiols (ca. 0.1 nM) can interrupt the formation of the active oxygen intermediates by forming Au–S covalent bonds on the surface of triangular AuNPs, resulting in a great decrease in CL intensity, while the other biomolecules including 19 standard amino acids, alcohols, organic acids, and saccharides have no effect on triangular AuNPs-catalyzed luminol CL signals. These significant features ...