Blue micro-highlighting in alumina-GO hybrid empowered by focused laser beam

We present a facile and direct method for selectively depositing amorphous aluminium oxide micro-flake or nanoparticles on graphene oxide (GO) by irradiating the GO film with a focused laser beam through a solution containing aluminium cations. Micro-landscapes comprising aluminium oxide (alumina) based compounds directed by the laser beam are constructed. The morphology and density of the deposited alumina are engineered through the variation of concentration of the solution used, the power and scanning speed of the laser. This method facilitates the rapid process of merging Al, O, C into the same matrix and thus resulted in the formation of carbon incorporated amorphous aluminium oxide that exhibits distinctive blue fluorescence upon UV excitation. This process is akin to the act of blue micro-highlighting on the surface of GO film. The GO film proves to be an ideal platform for the mask-free and non-contact micro-patterning process. The fluorescence micropattern is stable and continues to be fluorescence active even after a period of 397 days.