Opt Lett. 2023 Jun 1;48(11):2937-2940. doi: 10.1364/OL.491431.
Deterministic optical manipulation of fluorescent nanodiamonds (FNDs) in fluids has emerged as an experimental challenge in multimodal biological imaging. Designing and developing nano-optical trapping strategies to serve this purpose is an important task. In this Letter, we show how chemically prepared gold nanoparticles and silver nanowires can facilitate an opto-thermoelectric force to trap individual entities of FNDs using a long working distance lens, low power-density illumination (532-nm laser, 12 µW/µm). Our trapping configuration combines the thermoplasmonic fields generated by individual plasmonic nanoparticles and the opto-thermoelectric effect facilitated by the surfactant to realize a nano-optical trap down to a single FND that is 120 nm in diameter. We use the same trapping excitation source to capture the spectral signatures of single FNDs and track their position. By tracking the FND, we observe the differences in the dynamics of the FND around different plasmonic structures. We envisage that our drop-casting platform can be extrapolated to perform targeted, low-power trapping, manipulation, and multimodal imaging of FNDs inside biological systems such as cells.
在多模态生物成像中，确定性光学操纵荧光纳米金刚石（FNDs）已成为一个实验挑战。设计和开发纳米光学捕获策略是一项重要任务。在这封信件中，我们展示了如何使用化学制备的金纳米粒子和银纳米线，通过长工作距离透镜和低功率密度照明（532nm 激光，12µW/µm）利用光电热电效应来捕获单个 FND。我们的捕获配置结合了单个等离子体纳米粒子产生的热等离子体场和表面活性剂促进的光电热电效应，实现了纳米光学陷阱，可捕获直径为 120nm 的单个 FND。我们使用相同的捕获激发源来捕获单个 FND 的光谱特征并跟踪其位置。通过跟踪 FND，我们观察到 FND 在不同等离子体结构周围的动力学差异。我们设想我们的滴铸平台可以扩展到生物系统（如细胞）内部进行针对 FND 的低功率捕获、操纵和多模态成像。
