Soft nano-wrapping on graphene oxide by using metal–organic network films composed of tannic acid and Fe ions

Graphene oxide (GO) nanosheets were easily covered with uniform metal-organic network films composed of tannic acid and Fe ions. The surface morphology of the wrapped GO sheets was elucidated using atomic force, scanning electron, and transmission electron microscopy measurements. The GO sheets covered with the TA-Fe films on a substrate were reduced chemically without the collapse of the wrapped nanostructure of the TA-Fe/GO sheets. The modified GO sheets covered with TA-Fe were highly stable in water and easy to handle, which made it possible for placing on a microelectrode array for conductivity measurements.