title: Engineering of fluorescent emission of silk fibroin composite materials by material assembly.
abstract: This novel materials assembly technology endows the designated materials with additional/enhanced performance by fixing "functional components" into the materials. Such functional components are molecularly recognized and accommodated by the designated materials. In this regard, two-photon fluorescence (TPF) organic molecules and CdTe quantum dots (QDs) are adopted as functional components to functionalize silk fibers and films. TPF organic molecules, such as, 2,7-bis[2-(4-nitrophenyl) ethenyl]-9,9-dibutylfluorene (NM), exhibit TPF emission quenching because of the molecular stacking that leads to aggregation in the solid form. The specific recognition between -NO2 in the annealed fluorescent molecules and the -NH groups in the silk fibroin molecules decouples the aggregated molecules. This gives rise to a significant increase in the TPF quantum yields of the silk fibers. Similarly, as another type of functional components, CdTe quantum dots (QDs) with different sizes were also adopted in the silk functionalization method. Compared to QDs in solution the fluorescence properties of functionalized silk materials display a long stability at room temperature. As the functional materials are well dispersed at high quantum yields in the biocompatible silk a TPF microscope can be used to pursue 3D high-resolution imaging in real time of the TPF-silk scaffold.
authors.affiliation: Research Institute for Soft Matter and Biomimetics, College of Materials & Department of Physics, Xiamen University, Xiamen, 361005, P.R. China; College of Material Science and Engineering & State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620, P.R. China; Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore.
authors.forename: Naibo
authors.initials: N
authors.lastname: Lin
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Meng
authors.forename: Guoyang William
authors.initials: GW
authors.lastname: Toh
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhen
authors.forename: Yingying
authors.initials: Y
authors.lastname: Diao
authors.forename: Hongyao
authors.initials: H
authors.lastname: Xu
authors.forename: Xiang Yang
authors.initials: XY
authors.lastname: Liu
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D012831:Bombyx; D019187:Cadmium Compounds / Q000737:chemistry; D005349:Fibroins / Q000737:chemistry*; D005449:Fluorenes / Q000737:chemistry; D008422:Materials Testing; D051379:Mice; D008856:Microscopy, Fluorescence; D009596:Nitrophenols / Q000737:chemistry; D017785:Photons; D015202:Protein Engineering; D045663:Quantum Dots; D011789:Quantum Theory; D012996:Solutions; D013050:Spectrometry, Fluorescence; D013691:Tellurium / Q000737:chemistry; D013696:Temperature
chemical_list: D001672:Biocompatible Materials; D019187:Cadmium Compounds; D005449:Fluorenes; D009596:Nitrophenols; D012996:Solutions; C024719:4-nitrophenyl; D005349:Fibroins; D013691:Tellurium; C028337:cadmium telluride
keywords: fluorescence; hybrid materials; silk