Poly(adenine)-templated fluorescent Au nanoclusters for the rapid and sensitive detection of melamine

Abstract A rapid and label-free fluorescence sensing strategy has been established for the sensitive determination of melamine (MA) on the basis of poly(adenine) (poly (A))-templated Au nanoclusters (AuNCs). The poly(A)-templated AuNCs possessed excellent luminescence and photo-stability. In the presence of Hg 2+ , the luminescence of AuNCs was quenched by Hg 2+ through the metallophilic interactions between Au + and Hg 2+ . When melamine was introduced, the fluorescence intensity of sensing system could be recovered. There was a greater coordination interaction between Hg 2+ and melamine, which blocked the Hg 2+ -mediated fluorescence quenching of AuNCs. The assay allowed sensitive determination of melamine with a linear detection range from 50 nM to 100 μM. The limit of detection was as low as 16.6 nM. Furthermore, the label-free strategy was successfully employed for the detection of melamine concentration in real samples.