Oligonucleotide-stabilized fluorescent silver nanoclusters for turn-on detection of melamine

Fluorescence nanoclusters have been used for the determination of melamine for the first time. The method is based on the fluorescence turn-on of oligonucleotide-stabilized silver nanoclusters (DNA–Ag NCs) by melamine. The enhancement factors (I−I0)/I0 increase linearly with melamine concentrations over the range 5.0×10−8–7.0×10−6 M (R2=0.998). The detection limit is 1.0×10−8 M, which is approximately 2000 times lower than the US Food and Drug Administration estimated melamine safety limit of 20.0 μM. Furthermore, the milk samples spiked with melamine are analyzed with excellent recoveries.

► Fluorescent nanoclusters have been used for detecting melamine for the first time.
► It bases on fluorescence turn-on of nanoclusters by melamine.
► The fluorescent nanocluster used is oligonucleotide-stabilized silver.
► The method shows nice sensitivity.
► The milk samples spiked with melamine are analyzed with good recoveries.