Fluorescence Switchable Block Copolymer Particles with Doubly Alternate‐Layered Nanoparticle Arrays. Issue 28 (10th June 2021)

• Record Type: Journal Article
• Authors: Kim, Taewan; Xu, Meng; Lee, Young Jun; Ku, Kang Hee; Shin, Do Joong; Lee, Doh C.; Jang, Se Gyu; Yun, Hongseok; Kim, Bumjoon J.
• Is Part Of: Small. Volume 17:Issue 28(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-06-10
• Subjects: block copolymer particles -- fluorescence switching -- hybrid particles -- nanoparticle array -- nonradiative energy transfer; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202101222
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: The precise self‐assembly of block copolymers (BCPs) and inorganic nanoparticles (NPs) under 3D confinement offers microparticles with programmable nanostructures and functionalities. Here, fluorescence‐switchable hybrid microspheres are developed by forming doubly alternating arrays of Au NPs and CdSe/ZnS quantum dots (QDs) within polystyrene‐ block ‐poly(4‐vinylpyridine) (PS‐ b ‐P4VP) BCP domains. These doubly alternating arrays afford controlled nonradiative energy transfer (NRET) between the QDs and Au NPs that is dependent on the layer‐to‐layer distance. Solvent‐selective swelling of the hybrid particles tunes the distance between layers, modulating their NRET behavior and affording switchable fluorescence. The particle fluorescence is "OFF" in water through strong NRET from the QDs to Au NPs, but is "ON" in alcohols due to the increased distance between the Au NP and QD arrays in the swollen P4VP domains. The experimentally observed NRET intensity as a function of interparticle distance shows larger quenching efficiencies than those theoretically predicted due to the enhanced quenching within a 3D‐confined system. Finally, the robust and reversible fluorescence switching of the hybrid particles in different solvents is demonstrated, highlighting their potentials for bioimaging, sensing, and diagnostic applications. Abstract : An optically switchable hybrid microsphere is successfully demonstrated by the development of onion‐like block copolymer particles with doubly alternate layers of gold nanoparticles and quantum dots.