Active colloidal particles in emulsion droplets: a model system for the cytoplasm
Journal article, 2019

In living cells, molecular motors create activity that enhances the diffusion of particles throughout the cytoplasm, and not just ones attached to the motors. We demonstrate initial steps toward creating artificial cells that mimic this phenomenon. Our system consists of active, Pt-coated Janus particles and passive tracers confined to emulsion droplets. We track the motion of both the active particles and passive tracers in a hydrogen peroxide solution, which serves as the fuel to drive the motion. We first show that correcting for bulk translational and rotational motion of the droplets induced by bubble formation is necessary to accurately track the particles. After drift correction, we find that the active particles show enhanced diffusion in the interior of the droplets and are not captured by the droplet interface. At the particle and hydrogen peroxide concentrations we use, we observe little coupling between the active and passive particles. We discuss the possible reasons for lack of coupling and describe ways to improve the system to more effectively mimic cytoplasmic activity.

Author

Viva R. Horowitz

Harvard University

Hamilton College

Zachary C. Chambers

Harvard University

Irep Gözen

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry

University of Oslo

Harvard University

Thomas G. Dimiduk

Harvard University

Vinothan N. Manoharan

Harvard University

European Physical Journal: Special Topics

1951-6355 (ISSN) 1951-6401 (eISSN)

Vol. 227 17 2413-2424

Vesicle-assisted cryopreservation

Swedish Research Council (VR) (2013-414), 2013-07-01 -- 2016-06-30.

Subject Categories

Physical Chemistry

Other Chemical Engineering

Other Chemistry Topics

DOI

10.1140/epjst/e2019-800026-y

More information

Latest update

1/10/2020