Graphene oxide based two-dimensional optical tweezers for low power trapping of quantum dots and E. coli bacteria

Abstract

Optical tweezers have become an important non-invasive tool to manipulate and immobilize microscopic particles. In particular, plasmonic tweezers provide sufficient gradient force with much lower laser powers that are capable of trapping sub wavelength particles. However, the expensive and time-consuming fabrication techniques used in making plasmonic nanostructures often hinders direct application of such optical tweezers. We demonstrate the trapping of polystyrene beads, silica coated quantum dots and E. coli bacteria on the graphene oxide-based substrate with a multimode laser illumination at very low intensity. This system will also be an inexpensive but effective replacement of plasmonically-enhanced optical tweezers.