11-Mercaptoundecanoic acid functionalized gold nanoclusters as fluorescent probes for the sensitive detection of Cu2+ and Fe3+ ions

Abstract

Metal ions are physiologically essential, but excessive metal ions may cause severe risk to plants and animals. Here, we prepared gold nanoclusters (Au NCs) protected by 11-mercaptoundecanoic acid (11-MUA), which have excellent fluorescence properties for the detection of metal ions. The results showed that the copper ions (Cu2+) and iron ions (Fe3+) in the solution have obvious quenching effect on the fluorescence intensity of Au NCs. The detection range of Fe3+ was 0.8–4.5μmol/L (R2=0.992) and 4.5–11.0μmol/L (R2=0.997). And Cu2+ has a lower linear range (0.1–1.0μmol/L, R2=0.993). When EDTA was added into the reaction system, it was observed that the quenching effect of Cu2+ and Fe3+ on Au NCs showed different phenomenon. Then, the effect of metal ions on the fluorescence of Au NCs was investigated. The selective detection of Cu2+ was achieved by EDTA masking of Fe3+. In addition, we realized the metal ions detection application of Au NCs in the serum