Department of Atomic and Molecular Physics, Manipal Academy of Higher Education, Manipal, 576104, India.
Department of Atomic and Molecular Physics, Manipal Academy of Higher Education, Manipal, 576104, India; Center for Applied Nanosciences (CAN), Manipal Academy of Higher Education, Manipal, 576104, India.
Anal Chim Acta. 2024 Aug 15;1317:342903. doi: 10.1016/j.aca.2024.342903. Epub 2024 Jun 25.
Precise localized printing of plasmonic nanoparticles at desired locations can find a plethora of applications in diverse areas, including nanophotonics, nanomedicine, and microelectronics. The focused laser beam-assisted optical printing technique has illustrated its potential for the localized printing of differently shaped plasmonic particles. However, the technique is either time-consuming or often requires focused optical radiation, limiting its practical applications. While the optothermal printing technique has recently emerged as a promising technique for the direct and rapid printing of plasmonic nanoparticles onto transparent substrates at lower laser intensities, its potential to print the plasmonic nanoparticles to the core of the optical fiber platforms and utilize it for biological cell trapping as well as an analytical platform remains unexplored.
Herein, we demonstrate the thermal-convection-assisted printing of the Ag plasmonic nanoparticles from the plasmonic colloidal solution onto the core of single-mode optical fiber and its multi-functional applications. The direct printing of plasmonic structure on the fiber core via the thermal-convection mechanism is devoid of the requirement of any additional chemical ligand to the fiber core. Further, we demonstrated the potential of the developed plasmonic fiber probe as a multifunctional surface-enhanced Raman spectroscopic (SERS) platform for sensing, chemical reaction monitoring, and single-cell studies. The developed SERS fiber probe is found to detect crystal violet in an aqueous solution as low as 100 pM, with a plasmonic enhancement of 10. Additionally, the capability of the fiber-tip platform to monitor the surface plasmon-driven chemical reaction of 4-nitrothiophenol (4NTP) dimerizing into p, p'-dimercaptoazobenzene (DMAB) is demonstrated. Further, the versatility of the fiber probe as an effective platform for opto-thermophoretic trapping of single biological cells such as yeast, along with its Raman spectroscopic studies, is also shown here.
In this study, we illustrate for the first time the optothermal direct printing of plasmonic nanoparticles onto the core of a single-mode fiber. Further, the study demonstrates that such plasmonic nanoparticle printed fiber tip can act as a multi-functional analytical platform for optothermally trap biological particles as well as monitoring plasmon-driven chemical reactions. In addition, the plasmonic fiber tip can be used as a cost-effective SERS analytical platform and is thus expected to find applications in diverse areas.
在所需位置精确局部打印等离子体纳米粒子在各个领域都有广泛的应用，包括纳米光子学、纳米医学和微电子学。聚焦激光束辅助光学打印技术已经证明了其在不同形状等离子体粒子局部打印方面的潜力。然而，该技术要么耗时，要么通常需要聚焦的光学辐射，限制了其实际应用。虽然光热打印技术最近已成为在较低激光强度下直接快速打印等离子体纳米粒子到透明衬底上的一种有前途的技术，但它将等离子体纳米粒子打印到光纤平台的核心并将其用于生物细胞捕获以及分析平台的潜力仍未被探索。
本文展示了从等离子体胶体溶液中通过热对流辅助将 Ag 等离子体纳米粒子打印到单模光纤核心的方法，并展示了其多功能应用。通过热对流机制直接在光纤芯上打印等离子体结构，不需要对光纤芯进行任何额外的化学配体处理。此外，我们还展示了所开发的等离子体光纤探针作为多功能表面增强拉曼光谱（SERS）平台在传感、化学反应监测和单细胞研究中的潜力。所开发的 SERS 光纤探针被发现能够在水溶液中检测低至 100 pM 的结晶紫，等离子体增强因子为 10。此外，还证明了光纤尖端平台监测 4-硝基硫酚（4NTP）二聚形成对，对二甲氨基偶氮苯（DMAB）的表面等离子体驱动化学反应的能力。此外，还展示了光纤探针作为一种有效的光热电泳捕获单个生物细胞（如酵母）的平台的多功能性，以及它的拉曼光谱研究。
在这项研究中，我们首次展示了将等离子体纳米粒子直接打印到单模光纤核心上的光热方法。此外，该研究表明，这种打印有等离子体纳米粒子的光纤尖端可以作为一种多功能分析平台，用于光热捕获生物颗粒以及监测等离子体驱动的化学反应。此外，等离子体光纤尖端可用作具有成本效益的 SERS 分析平台，因此预计将在各个领域得到应用。
