5 years ago

Structure and Dynamics of a N-Methylfulleropyrrolidine-Mediated Gold Nanocomposite: A Spectroscopic Ruler

Structure and Dynamics of a N-Methylfulleropyrrolidine-Mediated Gold Nanocomposite: A Spectroscopic Ruler
Sanjeeb Sutradhar, Archita Patnaik
A mechanistic understanding of the structure and dynamics of a chemically tunable N-methylfulleropyrrolidine (8-NMFP)-assisted gold nanocomposite and its aggregation via a controllable interparticle interaction is reported as a function of the molar ratio and pH of the medium. Electronic structure calculations adopting density functional theory methods implied electrostatic interactions to play a dominant role between 8-NMFP and citrate-capped gold nanoparticles. MM+ molecular mechanics force field computations revealed intermolecular gold–gold interactions, contributing toward the formation of spherical composite aggregates. Corroborating these, optical absorption spectra showed the usual surface plasmon band along with a higher-wavelength feature at ∼600–650 nm, indicative of the aggregated nanocomposite. pH-controlled reversible tuning of the plasmonic features in the composite was evident in a pH interval ∼5–6.8, revealing prevalent interparticle electrostatic interactions. In addition, photoluminescence (PL) and time-correlated single-photon counting studies revealed a strong nanocomposite interaction with a pure fluorescent dye, Rhodamine B, indicating excitation energy transfer from the dye to the composite. The dye upon interaction with the nanocomposite showed a significant quenching of its PL intensity and shortening of lifetime. Energy coupling between the metal nanoparticle composite and the emitting molecular dipole resulted in a long-range surface energy transfer (SET) from the donor dye to the surface plasmon modes of the nanoparticle following a donor–acceptor distance dependence of 1/r4. This molecular beacon with correlation between the nanoscale structure and the nonradiative nanometal SET can be used as a spectroscopic/molecular ruler in probing advanced functional materials.

Publisher URL: http://dx.doi.org/10.1021/acsami.7b02640

DOI: 10.1021/acsami.7b02640

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.