Optical imaging of localized chemical events using programmable diamond quantum nanosensors.
Development of multifunctional nanoscale sensors working under physiological conditions enables monitoring of intracellular processes that are important for various biological and medical applications. By attaching paramagnetic gadolinium complexes to nanodiamonds (NDs) with nitrogen-vacancy (NV) centres through surface engineering, we developed a hybrid nanoscale sensor that can be adjusted to directly monitor physiological species through a proposed sensing scheme based on NV spin relaxometry. We adopt a single-step method to measure spin relaxation rates enabling time-dependent measurements on changes in pH or redox potential at a submicrometre-length scale in a microfluidic channel that mimics cellular environments. Our experimental data are reproduced by numerical simulations of the NV spin interaction with gadolinium complexes covering the NDs. Considering the versatile engineering options provided by polymer chemistry, the underlying mechanism can be expanded to detect a variety of physiologically relevant species and variables.
3. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany.
Torsten
T
Rendler
Institute of Organic Chemistry and Biochemistry of the CAS, Flemingovo nam. 2, 166 10 Prague 6, Czech Republic.|First Faculty of Medicine, Charles University, Katerinska 32, 121 08 Prague 2, Czech Republic.
Jitka
J
Neburkova
Faculty of Science, Department of Inorganic Chemistry, Charles University, Hlavova 2030, 128 43, Prague 2, Czech Republic.
Ondrej
0000-0002-9907-4047
O
Zemek
Faculty of Science, Department of Inorganic Chemistry, Charles University, Hlavova 2030, 128 43, Prague 2, Czech Republic.
Jan
J
Kotek
3. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany.
Andrea
A
Zappe
3. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany.
Zhiqin
Z
Chu
Institute of Organic Chemistry and Biochemistry of the CAS, Flemingovo nam. 2, 166 10 Prague 6, Czech Republic.
Petr
P
Cigler
3. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany.
Jörg
J
Wrachtrup
D015374:Biosensing Techniques / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D058612:Nanodiamonds / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D061848:Optical Imaging / Q000379:methods*; D010084:Oxidation-Reduction; D011789:Quantum Theory; D015203:Reproducibility of Results; D013997:Time Factors
D058612:Nanodiamonds