Effects of cold atmospheric plasma treatment on the morphological and optical properties of plasmonic silver nanoparticles
Effects of cold atmospheric plasma treatment on the morphological and optical properties of plasmonic silver nanoparticles
复制标题
DOI：
10.1088/1361-6528/ab9788
复制
发表时间：
2020-05
期刊：
影响因子：
3.5
通讯作者：
Apurva Sonawane;M. Mujawar;S. Bhansali
中科院分区：
文献类型：
--
作者：
Apurva Sonawane;M. Mujawar;S. Bhansali
由于对等离子体处理对纳米材料的形貌和其他性质的影响缺乏了解，等离子体工艺在纳米材料合成中的应用受到限制。在这里，我们研究了大气等离子体处理对银纳米颗粒的形貌和光学性质的影响。银纳米粒子沉积在基板上通过注入气溶胶到流动的氩气，然后用低温大气等离子体射流处理。等离子体处理后，平均Ag纳米颗粒直径减少到平均5 nm，这是伴随着一个蓝移的870 nm的表面等离子体共振峰，这些结果是类似的，通过在高温下的热处理所获得的。纳米颗粒尺寸的减小由在纳米颗粒表面上发生的氧化还原反应来解释，这从在经处理的样品中存在AgO和Ag2O拉曼峰是明显的。表面电荷由于等离子体处理而改变，如zeta电位的大变化所示，从未经处理的样品的+25.1 ± 4 mV到等离子体处理15分钟后的−25.9 ± 6 mV。等离子体处理的膜的表面增强拉曼光谱进行了荧光染料罗丹明6 G，其显示出相对于未处理的基板的信号强度的120倍的增强。因此，我们得出结论，冷等离子体处理修改的Ag纳米粒子的表面形态，从而提高其光学性能。这种技术可以应用于生物传感应用中使用的各种纳米颗粒系统。
The use of plasma processes in nanomaterial synthesis is limited by a lack of understanding of the effects of plasma treatment on the morphology and other properties. Here, we studied the effects of atmospheric plasma treatment on the morphology and optical properties of Ag nanoparticles. The Ag nanoparticles were deposited on substrates by injecting an aerosol into flowing argon gas and then treated with a low-temperature atmospheric plasma jet. After plasma treatment, the mean Ag nanoparticle diameter reduced to an average of 5 nm, which was accompanied by a blue shift of ∼70 nm in the peak of the surface plasmon resonance; these results are similar to those obtained by thermal treatment at elevated temperatures. The reduction in nanoparticle size is explained by the redox reaction that occurs on the nanoparticle surface, which is evident from the presence of AgO and Ag2O Raman peaks in the treated sample. The surface charge changed as a result of plasma treatment, as indicated by a large change in the zeta potential from +25.1 ± 4 mV for the untreated sample to −25.9 ± 6 mV after 15 min of plasma treatment. Surface-enhanced Raman spectroscopy of the plasma-treated films was carried out with the fluorescent dye Rhodamine 6 G, which showed a ∼120-fold enhancement in the signal intensity relative to the untreated substrates. We, therefore, conclude that cold-plasma treatment modified the surface morphology of the Ag nanoparticles, thereby enhancing their optical properties. This technique could be applied to a wide range of nanoparticle systems used in biosensing applications.