Sub-nanometer manipulation of multiple nanoparticles by non-uniformly back-gated graphene sheet/strips

Taking advantage of a non-uniformly biased graphene sheet, a novel electrically reconfigurable platform for sub-nanometer manipulation of nanoparticles (NPs) is proposed. Numerical simulations show that using a well-designed V-shaped back-gate contact, the graphene sheet can function as an inhomogeneous graphene strip with electrically tunable edges. Under certain conditions, localized surface plasmons (LSP) can be coupled to the induced edges, realizing strongly confined and enhanced edge-coupled LSP hot spots (trapping sites). Tuning the gate voltage tunes the induced edges and consequently the trapping sites with sub-nanometer resolution. Moreover, we demonstrate that using graphene strips (instead of a graphene sheet), the proposed structure can trap NPs in three dimensions and manipulate them in 2D. We believe this platform can open up exciting possibilities for future integrated reconfigurable lab-on-a-chip devices to accurately control the trapping sites, manipulate, route, and deliver NPs.