Sukmanee Thanyada, Szuster Michał, Gorski Aleksander, Hołdyński Marcin, Gawinkowski Sylwester
Institute of Physical Chemistry, Polish Academy of Sciences Kasprzaka 44/52 01-224 Warsaw Poland
Nanoscale Adv. 2023 Jun 21;5(14):3697-3704. doi: 10.1039/d3na00225j. eCollection 2023 Jul 11.
Metal nanoparticles have applications across a range of fields of science and industry. While there are numerous existing methods to facilitate their large-scale production, most face limitations, particularly in achieving reproducible processes and minimizing undesirable impurities. Common issues are varying particle sizes and aggregates with unfavorable spectral properties. Researchers are currently developing methods to separate or modify nanoparticle sizes and shapes post-synthesis and to eliminate impurities. One promising approach involves laser light irradiation and enables the changing of nanoparticle sizes and shapes while controlling crucial spectral parameters. In this work, we present a novel extension of this method by irradiating nanoparticle colloids with variable-wavelength nanosecond laser pulses on both sides of the extinction band. Our results demonstrate the use of gradual laser wavelength tuning to optimize the photothermal reshaping of gold nanorods and achieve precise control over the plasmon resonance band. By irradiating both sides of the plasmon resonance band, we execute a multistep tuning process, controlling the band's width and spectral position. A statistical analysis of SEM images reveals differences in the nanorod morphology when irradiated on the long- or short-wavelength side of the plasmon resonance band. The fine-tuning of plasmonic spectral properties is desirable for various applications, including the development of sensors and filters and the exploitation of the photothermal effect. The findings of this study can be extended to other plasmonic nanostructures.
金属纳米颗粒在科学和工业的一系列领域都有应用。虽然现有的促进其大规模生产的方法众多，但大多数都存在局限性，特别是在实现可重复的过程以及将不需要的杂质降至最低方面。常见问题是颗粒尺寸变化和具有不利光谱特性的聚集体。研究人员目前正在开发合成后分离或改变纳米颗粒尺寸和形状以及去除杂质的方法。一种有前景的方法涉及激光照射，能够在控制关键光谱参数的同时改变纳米颗粒的尺寸和形状。在这项工作中，我们通过在消光带两侧用可变波长纳秒激光脉冲照射纳米颗粒胶体，提出了该方法的一种新颖扩展。我们的结果表明，利用激光波长的逐渐调谐来优化金纳米棒的光热重塑，并实现对等离激元共振带的精确控制。通过对等离激元共振带两侧进行照射，我们执行了一个多步调谐过程，控制该带的宽度和光谱位置。对扫描电子显微镜图像的统计分析揭示了在等离激元共振带的长波长或短波长侧照射时纳米棒形态的差异。等离激元光谱特性的微调对于各种应用是可取的，包括传感器和滤波器的开发以及光热效应的利用方面。本研究的结果可以扩展到其他等离激元纳米结构。
