Electrochemical biomemory devices based on self-assembled graphene–Shewanella oneidensis composite biofilms

Abstract

Interest in biomaterial-combined memory devices is on the rise due to their redox properties and electron transport capacities in nature. However, many attempts have been made to develop the protein-based memory devices. Here, we developed a novel biomemory device that was comprised of living Shewanella oneidensis MR-1 cells and microbially reduced graphene. Charge storage and release properties of the composite biofilm were investigated with electrochemical methods. The results showed the redox behavior of in vivo c-type cytochromes with electrochemically controllable electric states regarded as “write” and “erase” processes. Furthermore, the graphene modified biofilm had significantly improved charge storage and release properties due to the synergetic effects between graphene and the electrochemically active biofilm. The current signal of the biomemory device was two orders higher than those of protein-based biomemory systems. The findings provide a new opportunity for memory design since the composite biofilm can be inexpensively produced and is self-repairable and replicable, which is advantageous to abiological and protein-based biomemory devices.