Fluorescence anisotropy metrology of electrostatically and covalently labelled silica nanoparticles

Philip Yip, Jan Karolin, David J. S. Birch

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

We compare determining the size of silica nanoparticles using the time-resolved fluorescence anisotropy decay of dye molecules when electrostatically and covalently bound to stable silica nanoparticles. Covalent labelling is shown to offer advantages by simplifying the dye rotational kinetics and the appropriateness of various kinetic models is discussed. Silica nanoparticles produced using Stober synthesis of tetraethylorthosilicate (TEOS) are found to be controllable between similar to 3.1 and 3.8 nm radius by adjusting the relative water: TEOS concentration. Covalent labelling with fluorescein 5(6)-isothiocyanate (FITC) bound to (3-aminopropyl) trimethoxysilane (FITC-APS) predicts a larger particle than electrostatically labelling with rhodamine 6G. The difference is attributed to the presence of an additional depolarization mechanism to Brownian rotation of the nanoparticle and dye wobbling with electrostatic labelling in the form of dye diffusion on the surface of the nanoparticle.

Original languageEnglish
Article number084003
Pages (from-to)-
Number of pages8
JournalMeasurement Science and Technology
Volume23
Issue number8
DOIs
Publication statusPublished - Aug 2012

Keywords

  • nanoparticles
  • ions
  • silica nanoparticles
  • fluorescence anisotropy

Fingerprint Dive into the research topics of 'Fluorescence anisotropy metrology of electrostatically and covalently labelled silica nanoparticles'. Together they form a unique fingerprint.

  • Student Theses

    Nanometrology using time-resolved fluorescence techniques

    Author: Yip, P., 8 Apr 2016

    Supervisor: Birch, D. (Supervisor) & Chen, Y. (Supervisor)

    Student thesis: Doctoral Thesis

    Cite this