Sui, S., Wang, Y., Kolewe, K., Srajer, V., Henning, R., Schiffman, J. D., Dimitrakopoulos, C., and Perry, S. L.  Graphene-Based Microfluidics for Serial Crystallography.  Lab Chip. (2016) abstract

A thin graphene layer improves the crystallography signal-to-noise ratio and acts as a barrier, protecting the protein crystals from dehydrating.