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

A novel method was used to synthesize triangular gold nanoparticles (AuNPs) (i.e., trisodium citrate reduction of HAuCl(4) 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 of triangular AuNPs-catalyzed luminol CL were the ability to detect aminothiols in the presence of other essential amino acids and biomolecules.