FLUORESCENCE DETECTION OF MELAMINE BASE ON FUNCTIONALIZED GRAPHENE OXIDE

Abstract

In this study, we report a new strategy to detect melamine. We present a sensitive and selective fluorescent aptasensor for detection melamine based on graphene oxide (GO) and SYBR Green I. Our strategy utilizes the efficient quenching ability of GO and the different interaction intensity of aptamer, aptamer/melamine complex with GO which directly induces the fluorescence intensity change. The results of experiment showed that, with the reaction mixture consisted of 1×NEBuffer 2, 80 nM T₅₅, 2×SG and different concentration of melamine, the fluorescence of SYBR Green I decreases as the concentration of melamine decreasing. In addition, some conditions and working curve of melamine are established with the concentration of range from 1 nM to 200 nM. Linear regression analysis of detection data yielded the following equation: y = 176.66 + 1.68 x, where y and x denoted the fluorescence peak intensity and melamine concentration, respectively. The peak intensity showed a linear correlation to the concentration of melamine in the range of 10 to 200 nM. The result further demonstrated that the fluorescence recovery was attributed to the formation of between double-stranded (dsDNA) structure by the specific interaction dsDNA and SYBR Green I (SG). Therefore, the GO-based biosensing platform is feasible to be used to selecting for detection melamine. This method provides a simple, rapid and high-throughput method for detection melamine and it could be widely applied to detect small molecules, other proteins and DNAs with specific designed oligonucleotides because of its excellent sequence-independent property.