Surface Sensing of Quantum Dots by Electron Spins.
The nanoscale design of quantum dots (QDs) requires advanced analytical techniques. However, those that are commonly used do not have sufficient sensitivity or spatial resolution. Here, we use magnetic resonance techniques combined with paramagnetic Mn impurities in PbS QDs for sensitive probing of the QD surface and environment. In particular, we reveal inequivalent proton spin relaxations of the capping ligands and solvent molecules, strengths and anisotropies of the Mn nuclear spin interactions, and Mn nuclei distances with ∼1 Å sensitivity. These findings demonstrate the potential of magnetically doped QDs as sensitive magnetic nanoprobes and the use of electron spins for surface sensing.
School of Physics and Astronomy, The University of Nottingham , Nottingham NG7 2RD, United Kingdom.
Fabrizio
F
Moro
School of Physics and Astronomy, The University of Nottingham , Nottingham NG7 2RD, United Kingdom.|School of Chemistry, University of Lincoln , Lincoln LN6 7DL, United Kingdom.
Lyudmila
L
Turyanska
School of Physics and Astronomy, The University of Nottingham , Nottingham NG7 2RD, United Kingdom.
James
J
Wilman
Centre for Biomolecular Sciences, School of Chemistry, The University of Nottingham , Nottingham NG7 2RD, United Kingdom.
Huw E L
HEL
Williams
The Photon Science Institute and School of Chemistry, University of Manchester , Manchester M13 9PL, United Kingdom.
Alistair J
AJ
Fielding
School of Physics and Astronomy, The University of Nottingham , Nottingham NG7 2RD, United Kingdom.
Amalia
A
Patanè
Colloidal quantum dots; electron spin echo envelope modulation (ESEEM); electron spin resonance (ESR); electron−nuclear double resonance (ENDOR); magnetic doping; nuclear magnetic resonance (NMR)