Gallardo-Rivera Oswaldo, Rivera Anahi, Meza Espinoza Luis Octavio, Lazcano Ortiz Zorayda
Instituto de Física Luis Rivera Terrazas, Benemérita Universidad Autónoma de Puebla, Puebla 72000, Mexico.
Ingeniería Automotriz, Universidad Politécnica de Amozoc, Amozoc de Mota 72980, Puebla, Mexico.
ACS Omega. 2025 Mar 17;10(12):11806-11816. doi: 10.1021/acsomega.4c07927. eCollection 2025 Apr 1.
This study investigates the luminescent dynamics of poly(methyl methacrylate) (PMMA) doped with rare earth ions, focusing on donor and acceptor ions. The acceptor ions feature two excited energy levels, enabling upconversion through energy transfer (ET) with the donor ions. Additionally, this study examines how the luminescent dynamics is affected by the enhanced electric field achieved through plasmonic resonance with metallic nanoparticles (NPs). The motivation behind this study lies in the necessity to enhance the luminescence properties of materials for advanced applications in bioimaging and optical sensors. Utilizing Förster's theory and the MNPBEM toolbox in MATLAB, the optimal NP radii for gold and silver, as well as the excitation wavelengths that maximize electric field amplification, were determined. Our findings show that silver NPs offer superior electric field enhancement (up to 8.7 times) compared to gold NPs (3.6 times). Emission amplification, influenced by the NP radius, excitation wavelength, and ion density, showed a significant correlation due to ET and excited-state absorption processes. Notably, silver NPs exhibited a maximum emission amplification of the second excited level of the acceptor ions of approximately 150 times. These findings offer valuable insights into utilizing plasmonic resonance and rare earth doping to enhance luminescent properties in materials with potential applications in biomedical imaging, biosensing, photovoltaic devices, and other advanced optical technologies. This work differs from previously published studies by focusing on the interaction of both excited-state absorption and ET in a model that considers the upconversion process and demonstrating a 2-fold higher electric field enhancement with silver NPs compared to gold. Furthermore, this study explores the optimization of NP size and excitation wavelengths to maximize the enhancement, which, to our knowledge, was not previously considered.
本研究调查了掺杂稀土离子的聚甲基丙烯酸甲酯（PMMA）的发光动力学，重点关注施主离子和受主离子。受主离子具有两个激发能级，能够通过与施主离子的能量转移（ET）实现上转换。此外，本研究还考察了通过与金属纳米颗粒（NP）的等离子体共振实现的增强电场如何影响发光动力学。本研究的动机在于需要增强材料的发光特性，以用于生物成像和光学传感器等先进应用。利用福斯特理论和MATLAB中的MNPBEM工具箱，确定了金和银的最佳NP半径以及使电场放大最大化的激发波长。我们的研究结果表明，与金纳米颗粒（3.6倍）相比，银纳米颗粒提供了更高的电场增强（高达8.7倍）。受NP半径、激发波长和离子密度影响的发射放大，由于ET和激发态吸收过程而呈现出显著的相关性。值得注意的是，银纳米颗粒在受主离子的第二激发能级上表现出最大约150倍的发射放大。这些发现为利用等离子体共振和稀土掺杂来增强材料的发光特性提供了有价值的见解，这些材料在生物医学成像、生物传感、光伏器件和其他先进光学技术中具有潜在应用。这项工作与之前发表的研究不同，它关注在考虑上转换过程的模型中激发态吸收和ET的相互作用，并证明银纳米颗粒的电场增强比金纳米颗粒高2倍。此外，本研究探索了NP尺寸和激发波长的优化以实现最大增强，据我们所知，这在以前并未被考虑。
