Optical Materials and Bio-imaging Research Laboratory, Department of Physics, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India.
Biophotonics Lab, Department of Bioengineering and Biotechnology, Birla Institute of Technology, Mesra, Ranchi, Jharkhand 835215, India.
Biomed Mater. 2024 Jul 3;19(5). doi: 10.1088/1748-605X/ad580b.
In this investigation, we embarked on the synthesis of polyethylene glycol coated NaGdF:Tm/Ybupconversion nanoparticles (UCNPs), aiming to assess their utility in enhancing image contrast within the context of swept source optical coherence tomography (OCT) and photo-thermal OCT imaging. Our research unveiled the remarkable UC emissions stemming from the transitions of Tmions, specifically theG→Htransitions, yielding vibrant blue emissions at 472 nm. We delved further into the UC mechanism, meticulously scrutinizing decay times and the nanoparticles' capacity to convert radiation into heat. Notably, these nanoparticles exhibited an impressive photo-thermal conversion efficiency of 37.5%. Furthermore, our investigations into their bio-compatibility revealed a promising outcome, with more than 90% cell survival after 24 h of incubation with HeLa cells treated with UCNPs. The nanoparticles demonstrated a notable thermal sensitivity of 4.7 × 10Kat 300 K, signifying their potential for precise temperature monitoring at the cellular level.
在本研究中，我们着手合成了聚乙二醇包覆的 NaGdF:Tm/Yb 上转换纳米粒子（UCNPs），旨在评估其在基于扫频源光学相干断层扫描（OCT）和光热 OCT 成像的增强图像对比度方面的应用。我们的研究揭示了源自 Tm 离子跃迁的显著上转换发射，特别是 G→H 跃迁，产生了在 472nm 处的明亮蓝色发射。我们进一步研究了上转换机制，仔细研究了衰减时间和纳米粒子将辐射转化为热能的能力。值得注意的是，这些纳米粒子表现出令人印象深刻的光热转换效率为 37.5%。此外，我们对其生物相容性的研究也取得了有希望的结果，在与用 UCNPs 处理的 HeLa 细胞孵育 24 小时后，细胞存活率超过 90%。纳米粒子在 300 K 时表现出显著的热灵敏度为 4.7×10-3 K，表明其在细胞水平上进行精确温度监测的潜力。
