Sensitive Detection of Small Particles in Fluids Using Optical Fiber Tip with Dielectrophoresis.

ABSTRACT: This work presents using a tapered fiber tip coated with thin metallic film to detect small particles in water with high sensitivity. When an AC voltage applied to the Ti/Al coated fiber tip and indium tin oxide (ITO) substrate, a gradient electric field at the fiber tip induced attractive/repulsive force to suspended small particles due to the frequency-dependent dielectrophoresis (DEP) effect. Such DEP force greatly enhanced the concentration of the small particles near the tip. The increase of the local concentration also increased the scattering of surface plasmon wave near the fiber tip. Combined both DEP effect and scattering optical near-field, we show the detection limit of the concentration for 1.36 μm polystyrene beads can be down to 1 particle/mL. The detection limit of the Esch

SUBMITTER: Tai YH 

PROVIDER: S-EPMC4813878 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature