@article{oai:repo.qst.go.jp:00081089,
 author = {Lazarova, Dessislava and Semkova, Severina and Zlateva, Genoveva and Zhelev, Zhivko and Higashi, Tatsuya and Aoki, Ichio and Bakalova, Rumiana and Tatsuya, Higashi and Ichio, Aoki and Bakalova, Rumiana},
 issue = {5},
 journal = {Analytical Chemistry},
 month = {Feb},
 note = {Total redox capacity (TRC) and oxidative stress (OxiStress) of biological objects (such as cells, tissues, body fluids) are one of the most frequently analyzed parameters in the life science. Development of highly sensitive molecular probes and analytical methods for detection of these parameters is a rapidly growing sector of BioTech R&D industry. The aim of the present study was to develop quantum sensors for tracking the TRC and OxiStress in living biological objects using EPR, MRI, and optical imaging. We describe a new two-set sensor system: (i) TRC sensor – QD@CD-TEMPO; and (ii) OxiStress sensor – QD@CDTEMPOH. Both redox-sensors are composed of small-size quantum dots (QDs), coated with multi-nitroxide-functionalized cyclodextrin (paramagnetic CD-TEMPO or diamagnetic CD-TEMPOH) conjugated with Triphenylphosphonium (TPP) groups. The TPP-groups were added to achieve intracellular delivery and mitochondrial localization. Nitroxide residues interact simultaneously with various oxidizers and reducers, and the sensors are transformed from paramagnetic radical form (QD@CD-TEMPO) into diamagnetic hydroxylamine form (QD@CD-TEMPOH) and vice-versa, due to nitroxide redox-cycling. These chemical transformations are accompanied by a characteristic dynamics of their contrast features due to quenching of QD fluorescence by nitroxide radical. The sensors were applied for EPR/fluorescent analysis of TRC and OxiStress in vitro on isolated cells with different proliferative index, as well as for non-invasive magnetic resonance imaging of redox imbalance and severe oxidative stress in vivo on mice with renal dysfunction.},
 pages = {2828--2837},
 title = {Quantum Sensors To Track Total Redox-Status and Oxidative Stress in Cells and Tissues Using Electron-Paramagnetic Resonance, Magnetic Resonance Imaging, and Optical Imaging},
 volume = {93},
 year = {2021}
}