Understanding the interfacial interactions between dopamine and different graphenes for biomedical materials

The interaction mechanisms of dopamine (DA) on pristine graphene (G), Stone-Wales defective graphene (DG), graphene oxide (GO), and Fe-doped graphene (Fe-G) surfaces have been investigated via simulation. It has been found that the adsorption configurations of DA molecules on graphene-based materials greatly affect the interaction energies between the DA molecules and graphene surfaces. The interactions between a DA molecule and G or DG surface were predominantly regarded as a physical adsorption process, wherein a DA molecule was chemisorbed on the GO surface with -OH in the DA molecule pointing towards the GO surface. It was also demonstrated that DA could be chemisorbed on the Fe-G surface. The study forms a guideline for designing graphene-based materials with specific structure or chemical groups to satisfy the demands for DA related applications.