title: Stably Doped Conducting Polymer Nanoshells by Surface Initiated Polymerization.
abstract: Despite broad applications ranging from electronics to biomedical sensing and imaging, a long-standing problem of conducting polymers is the poor resistance to dedoping, which directly affects their signature electrical and optical properties. This problem is particularly significant for biomedical uses because of fast leaching of dopant ions in physiological environments. Here, we describe a new approach to engineer multimodal core-shell nanoparticles with a stably doped conductive polymer shell in biological environments. It was achieved by making a densely packed polymer brush rather than changing its molecular structure. Polyaniline (PANI) was used as a model compound due to its concentrated near-infrared (NIR) absorption. It was grafted onto a magnetic nanoparticle via a polydopamine intermediate layer. Remarkably, at pH 7 its conductivity is ca. 2000× higher than conventional PANI nanoshells. Similarly, its NIR absorption is enhanced by 2 orders of magnitude, ideal for photothermal imaging and therapy. Another surprising finding is its nonfouling property, even outperforming polyethylene glycol. This platform technology is also expected to open exciting opportunities in engineering stable conductive materials for electronics, imaging, and sensing.
authors.affiliation: Department of Bioengineering, University of Washington , Seattle, Washington 98195, United States.
authors.forename: Junwei
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Bioengineering, University of Washington , Seattle, Washington 98195, United States.
authors.forename: Soon Joon
authors.initials: SJ
authors.lastname: Yoon
authors.affiliation: Department of Bioengineering, University of Washington , Seattle, Washington 98195, United States.
authors.forename: Bao-Yu
authors.initials: BY
authors.lastname: Hsieh
authors.affiliation: Department of Bioengineering, University of Washington , Seattle, Washington 98195, United States.
authors.forename: Wanyi
authors.initials: W
authors.lastname: Tai
authors.affiliation: Department of Bioengineering, University of Washington , Seattle, Washington 98195, United States.
authors.forename: Matthew
authors.initials: M
authors.lastname: O'Donnell
authors.affiliation: Department of Bioengineering, University of Washington , Seattle, Washington 98195, United States.
authors.forename: Xiaohu
authors.initials: X
authors.lastname: Gao
mesh_terms: D049329:Nanostructures; D058105:Polymerization; D011108:Polymers / Q000737:chemistry*
chemical_list: D011108:Polymers
keywords: Conducting polymer; antifouling capability; dedoping resistance; nanoshell; polymer brush; surface initiated polymerization