TY - JOUR
T1 - Cellular temperature probing using optically trapped single upconversion luminescence
AU - Suresh, K.
AU - Monisha, K.
AU - Bankapur, Aseefhali
AU - Rao, Subha Krishna
AU - Mutalik, Srinivas
AU - George, Sajan D.
N1 - Funding Information:
SDG acknowledges the financial support from Science and Engineering Research Board (SERB) under project grant no. SERB/DST/EMR/2016/002424 and CRG/2020/002096 . Suresh K also wishes to acknowledge the Manipal Academy of Higher Education for providing the research scholarship. Authors also financial support from the Manipal Academy of Higher Education and the FIST program of the Government of India ( SR/FST/PSI-174/2012 ).
Publisher Copyright:
© 2023 Elsevier B.V.
PY - 2023/9/8
Y1 - 2023/9/8
N2 - Background: The thermally coupled energy states that contribute to the upconversion luminescence of rare earth element-doped nanoparticles have been the subject of intense research due to their potential nanoscale temperature probing. However, the inherent low quantum efficiency of these particles often limits their practical applications, and currently, surface passivation and incorporation of plasmonic particles are being explored to improve the inherent quantum efficiency of the particle. However, the role of these surface passivating layers and the attached plasmonic particles in the temperature sensitivity of upconverting nanoparticles while probing the intercellular temperature has not been investigated thus far, particularly at the single nanoparticle level. Results: The analysis of the study on the thermal sensitivity of oleate-free UCNP, UCNP@SiO2, and UCNP@SiO2@Au particles is carried out at a single particle level in a physiologically relevant temperature range (299 K–319 K) by optically trapping the particle. The thermal relative sensitivity of the as-prepared upconversion nanoparticle (UCNP) is found to be greater than that of UCNP@SiO2 and UCNP@SiO2@Au particles in an aqueous medium. An optically trapped single luminescence particle inside the cell is used to monitor the temperature inside the cell by measuring the luminescence from the thermally coupled states. The absolute sensitivity of optically trapped particles inside the biological cell increases with temperature, with a greater impact on the bare UCNP, which exhibits higher values for thermal sensitivity than UCNP@SiO2 and UCNP@SiO2@Au. The thermal sensitivity of the trapped particle inside the biological cell at 317 K indicates the thermal sensitivity of UCNP > UCNP@SiO2@Au > UCNP@SiO2 particles. Significance and novelty: Compared to bulk sample-based temperature probing, the present study demonstrates temperature measurement at the single particle level by optically trapping the particle and further explores the role of the passivating silica shell and the incorporation of plasmonic particles on thermal sensitivity. Furthermore, thermal sensitivity measurements inside a biological cell at the single particle level are investigated and illustrated that thermal sensitivity at a single particle is sensitive to the measuring environment.
AB - Background: The thermally coupled energy states that contribute to the upconversion luminescence of rare earth element-doped nanoparticles have been the subject of intense research due to their potential nanoscale temperature probing. However, the inherent low quantum efficiency of these particles often limits their practical applications, and currently, surface passivation and incorporation of plasmonic particles are being explored to improve the inherent quantum efficiency of the particle. However, the role of these surface passivating layers and the attached plasmonic particles in the temperature sensitivity of upconverting nanoparticles while probing the intercellular temperature has not been investigated thus far, particularly at the single nanoparticle level. Results: The analysis of the study on the thermal sensitivity of oleate-free UCNP, UCNP@SiO2, and UCNP@SiO2@Au particles is carried out at a single particle level in a physiologically relevant temperature range (299 K–319 K) by optically trapping the particle. The thermal relative sensitivity of the as-prepared upconversion nanoparticle (UCNP) is found to be greater than that of UCNP@SiO2 and UCNP@SiO2@Au particles in an aqueous medium. An optically trapped single luminescence particle inside the cell is used to monitor the temperature inside the cell by measuring the luminescence from the thermally coupled states. The absolute sensitivity of optically trapped particles inside the biological cell increases with temperature, with a greater impact on the bare UCNP, which exhibits higher values for thermal sensitivity than UCNP@SiO2 and UCNP@SiO2@Au. The thermal sensitivity of the trapped particle inside the biological cell at 317 K indicates the thermal sensitivity of UCNP > UCNP@SiO2@Au > UCNP@SiO2 particles. Significance and novelty: Compared to bulk sample-based temperature probing, the present study demonstrates temperature measurement at the single particle level by optically trapping the particle and further explores the role of the passivating silica shell and the incorporation of plasmonic particles on thermal sensitivity. Furthermore, thermal sensitivity measurements inside a biological cell at the single particle level are investigated and illustrated that thermal sensitivity at a single particle is sensitive to the measuring environment.
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U2 - 10.1016/j.aca.2023.341530
DO - 10.1016/j.aca.2023.341530
M3 - Article
AN - SCOPUS:85162738037
SN - 0003-2670
VL - 1273
JO - Analytica Chimica Acta
JF - Analytica Chimica Acta
M1 - 341530
ER -