(464e) Nanoscale Interactions between Graphene and Lung-Surfactant Monolayers

Results of experimental work investigating the nanoscale interactions between graphene and a phospholipid monolayer at an air-water interface will be discussed. Little is known about the way two-dimensional particles such as graphene interact with biological membranes, but as use and availability of two-dimensional particles increases in various industries, their interaction with biological membranes such as those in lung alveoli will become more common. The consequences of those interactions will depend on the way they interact at the nanometer scale, and although there are a number of molecular dynamics studies focused on such systems, there are very few experimental studies of these systems. The lack of experimental studies is due in part to experimental challenges studying these nano-scale systems, but we have developed an experimental platform for fabricating graphene particles of controlled size and shape and introducing them to a phospholipid monolayer where the interactions can be observed with epifluorescence microscopy. We seek to understand where two-dimensional particles will arrange within a phospholipid membrane (e.g. surf the hydrocarbon tails, or displace the lipids entirely), and to understand how rapidly such particles will diffuse laterally along the membrane. Results of measurements of mean-squared displacement of graphene particles as a function of area coverage of the lung surfactant dipalmitoylphosphatidylcholine (DPPC) will be discussed. Experimental measurements will be compared with theoretical values, and the implications for the nanoscale interactions in this system and potentially other similar systems will be discussed.