Light-activated Janus self-assembled capsule micromotors

We report a self-propelled Janus micromotor composed by chitosan (CHI) and alginate (ALG) multilayer capsule driven by near-infrared (NIR) illumination. The CHI/ALG multilayer capsules were prepared using conventional template-assisted layer-by-layer (LbL) self-assembly. Subsequently, gold nanorods (GNRs) were deposited on one side of the assembled capsules using microcontact printing method. The GNRs-modified Janus capsules can be driven by NIR irradiation owing to the generated thermal gradient and no additional chemical fuel are requested. It is also shown the moving speed of these Janus micromotors can be regulated by irradiation intensity and reach to 23.27 mu m/s at a laser power of 9.6 J/cm(2). Since no additional chemical component as fuel, this GNRs-modified ALG/CHI multilayer Janus capsule micromotor shows great potential as a biomimetic delivery platform in biomedical field. (C) 2015 Elsevier B.V. All rights reserved.