Sarmanova Olga E, Burikov Sergey A, Laptinskiy Kirill A, Kotova Olga D, Filippova Ekaterina A, Dolenko Tatiana A
Faculty of Physics, Lomonosov Moscow State University, Moscow, Russia.
Faculty of Physics, Lomonosov Moscow State University, Moscow, Russia.
Spectrochim Acta A Mol Biomol Spectrosc. 2020 Nov 5;241:118627. doi: 10.1016/j.saa.2020.118627. Epub 2020 Jun 19.
The luminescence intensity ratio method, exploiting the temperature-dependent luminescence of the thermally coupled energy levels, is regarded as a very promising approach for optical temperature measurement at the cellular level. In this study, it was found that bare NaYF:Yb/Tm nanoparticles cannot be used as a cellular thermosensor in principle because of their tendency to aggregate, which significantly affects the luminescent properties of the complex, introducing uncertainty in the intensity ratio measurement. NaYF:Yb/Tm up-conversion nanoparticles, coated with polyethylene glycol (PEG) and carboxyl groups (COOH), on the other hand, proved to be promising candidates for the role of thermosensors. For the first time the temperature sensitivity of the NaYF:Yb/Tm@PEG@COOH thermosensor was calculated in water and in biotissues. It was found that the sensitivity of the thermosensor increased by 1.3 times during the transition from water to egg white and urine - from 1.17% × K to 1.58% × K. This effect is associated with the chemical composition of the studied media. The results obtained suggest that using upconversion nanocomplexes as primary thermosensors is still difficult.
利用热耦合能级的温度依赖性发光的发光强度比法，被认为是细胞水平光学温度测量中一种非常有前景的方法。在本研究中，发现裸NaYF:Yb/Tm纳米颗粒由于其聚集倾向，原则上不能用作细胞热传感器，这会显著影响复合物的发光特性，给强度比测量带来不确定性。另一方面，涂覆有聚乙二醇（PEG）和羧基（COOH）的NaYF:Yb/Tm上转换纳米颗粒被证明是热传感器角色的有前景候选者。首次计算了NaYF:Yb/Tm@PEG@COOH热传感器在水和生物组织中的温度灵敏度。发现热传感器在从水过渡到蛋清和尿液时灵敏度提高了1.3倍——从1.17%×K提高到1.58%×K。这种效应与所研究介质的化学成分有关。所得结果表明，将上转换纳米复合物用作初级热传感器仍然困难。
