Poly thymine stabilized copper nanoclusters as a fluorescence probe for melamine sensing.

In this work, poly-thymine stabilized copper nanoclusters have been used as a fluorescence probe for melamine sensing for the first time. Melamine can bind to thymine through hydrogen bond, which could dramatically enhance the fluorescence intensity of poly-thymine stabilized copper nanoclusters. The enhancement factors (I-I0)/I0 increase linearly with the lgCmelamine over the melamine concentration range of 0.1 µM to 6 µM. The detection limit of melamine is 95 nM, which is 200 times lower than the US Food and Drug Administration estimate melamine safety limit 20 µM. Melamine in milk was detected with good recovery, which suggested that this novel fluorescence probe has great potential in practical application.