Visible-light-driven TiO2@N-Au nanorobot penetrating the vitreous

For ophthalmology, there remain many uncertainties and challenges for traditional passive diffusion-based drug intervention. One of the major hurdles is the limited penetration caused by the complex vitreous bodies and biological macromolecules within. Here, we demonstrate for the first time that a novel TiO2@N-Au nanowire (NW) motor/locomotive robot actuated by wireless natural visible light can autonomously and efficiently penetrate into the vitreous body via photoelectrophoresis mechanism. With the efficient propulsion, and the nanoscale size of the NW motor matching the voids of the vitreous network, noninvasive advancing deep into the vitreous body and overcoming the inhomogeneous non-Newtonian fluid (shear thinning and viscoelastic) barriers are allowed. We envision the active visible-light-powered TiO2@N-Au NW motor holds immense application prospects for deep eye diseases and wireless bioelectronics.