A specific DNA sensor to detect melamine using graphene oxide

The addition of melamine into food caused serious social problems, hence the need of an easy way of detecting melamine and its derivatives. In this paper, we propose a new method based on the unique quenching effect of graphene oxide (GO). The difference of GO interaction with DNA and melamine is the basis of selective detection of melamine. GO adsorbs DNA and efficiently quenches the fluorescence of labeled fluorophores. The stronger interaction of melamine with GO than DNA leads to a competitive displacement of DNA out of the surface of GO, then a significant fluorescence increase appears. As a control, the glucose, maltose, and fructose do not cause significant fluorescence increase. This method is simple, inexpensive, sensitive and selective. It is suitable for rapid screening of large quantities of samples.