A dihydropyridine derivative as a highly selective fluorometric probe for quantification of Au3+ residue in gold nanoparticle solution

Abstract

Abstract Novel dihydroquinoline derivatives (DHP and DHP-OH) were synthesized in one pot via a tandem trimerization-cyclization of methylpropiolate. DHP and DHP-OH possess strong blue fluorescence with high quantum efficiencies over 0.70 in aqueous media. DHP-OH displays a remarkable fluorescence quenching selectively to the presence of Au3+ through the oxidation of dihydropyridine to pyridinium ion as confirmed by NMR and HRMS. DHP-OH was used to demonstrate the quantitative analysis of Au3+ in water samples with limit of detection of 32.8 ppb and excellent recovery (>95%). This fluorescent probe was also applied for determination of Au3+ residue in the gold nanoparticle solution and paper-based sensing strip for on-site detection of Au3+.