Graphene oxide linking layers for highly sensitive SPR biosensing of small molecules

The development of graphene oxide (GO) interfaces can significantly improve the performance of modern surface plasmon resonance (SPR) biosensors. GO linking layers have high binding capacity for a wide range of chemical and biological ligands owing to large surface area of GO and its unique biochemical properties. Here, we compared binding capacities of GO linking layers with different thicknesses and widely-used hydrogel linking layers based on carboxymethylated dextran (CMD). SPR measurements corresponding to the activation of carboxyl groups on the surface of SPR chips showed that the binding capacity of a 50-nm-thick GO linking layer is 30-times higher than for 150-nm-thick CMD layer, which results in enhanced biosensing sensitivity of GO chips and can lead to novel applications for SPR biosensing.