Photochemically Induced Folding of Single Chain Polymer Nanoparticles in Water

Carolin Heiler; Janin T Offenloch; Eva Blasco; Christopher Barner-Kowollik

doi:10.1021/acsmacrolett.6b00858

Photochemically Induced Folding of Single Chain Polymer Nanoparticles in Water

ACS Macro Lett. 2017 Jan 17;6(1):56-61. doi: 10.1021/acsmacrolett.6b00858. Epub 2016 Dec 29.

Authors

Carolin Heiler^{1

2}, Janin T Offenloch^{1

2}, Eva Blasco^{1

2}, Christopher Barner-Kowollik^{1

2

3}

Affiliations

¹ Preparative Macromolecular Chemistry, Institut für Technische Chemie und Polymerchemie, Karlsruhe Institute of Technology (KIT), Engesserstr. 18, 76131 Karlsruhe, Germany.
² Institut für Biologische Grenzflächen, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
³ School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, 2 George Street, Brisbane, QLD 4000, Australia.

PMID: 35651105
DOI: 10.1021/acsmacrolett.6b00858

Abstract

We pioneer the synthesis of fluorescent single chain nanoparticles (SCNPs) via UV-light induced folding based on tetrazole chemistry directly in pure water. Water-soluble photoreactive precursor polymers based on poly(acrylic acid) (PAA) bearing tetrazole, alkene and tetraethylene glycol monomethyl ether moieties, (PAA_n(Tet/p-Mal/TEG)), or simply tetrazoles moieties, PAA_n(Tet), were generated via RAFT polymerization. While tetrazole, ene, and acrylic acid containing polymers fold via dual nitrile imine-mediated tetrazole-ene cycloaddition (NITEC) as well as nitrile imine-carboxylic acid ligation (NICAL), tetrazole and acrylic acid only functional prepolymers fold exclusively via NICAL. A detailed study of the underpinning photochemistry of NITEC and NICAL is also included. The resulting water-soluble SCNPs were carefully characterized via analytical techniques such as NMR, UV-vis, and fluorescence spectroscopy, as well as SEC and DLS.