Glutathione capped silver nanoclusters-based fluorescent probe for highly sensitive detection of Fe3+

Glutathione capped silver nanoclusters (GSH@Ag NCs) were prepared by facile sonachemical method in aqueous solution. A new GSH@Ag NCs fluorescent probe for the detection of Fe3+ has been designed based on the significant fluorescence quenching of GSH@Ag NCs. The response to Fe3+ allows for a linear dynamic range from 5 × 10−7 mol/L to 2 × 10−5 mol/L with a detection limit of 1.2 × 10−7 mol/L. The other common metal ions did not cause interference. Moreover, the proposed method was applied to the detection of serum iron contents in human serum samples and the recoveries were 84.12–101.70%. In addition, an interesting fluorescence signal “off-on” phenomena of the Ag NCs probe was observed. The fluorescence of the Ag NCs probe could be switched “off” with addition of Fe3+ solution and “on” in the presence of EDTA solution because of the competition for Fe3+. This property enables the probe to be possible for constructing practicable and reusable sensor. All above features indicated that functionalized silver nanoclusters-based fluorescent probe as sensing platform hold great potential for applications in biological and analytical detection.