Plasmonic Brownian Ratchets for Directed Transport of Analytes.

ABSTRACT: Plasmonic nanostructures provide strong optical near-fields for trapping and manipulating nanosized particles, but converting these interactions into robust directional transport has remained challenging. Here we demonstrate a plasmonic Brownian ratchet that rectifies colloidal diffusion using an asymmetric gold nanoarray under continuous-wave illumination. Finite-element simulations reveal anisotropic near-field distributions that bias optical forces, and experiments confirm directed motion for 40-200 nm nanoparticles of various compositions (dielectric, semiconducting and metallic). We show that, under periodic light modulation, nanoparticles undergo unidirectional lateral transport with velocities up to 2.4 μm/s at incident intensities below 1 kW/cm². These results establish

SUBMITTER: Palma do Carmo M 

PROVIDER: S-EPMC12810488 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature