Edison Thomas Nesakumar Jebakumar Immanuel, Atchudan Raji, Kamal Chennappan, Lee Yong Rok
School of Chemical Engineering, Yeungnam University, Gyeongsan, 712-749, Republic of Korea.
Department of Chemistry, VSA Group of Institutions, Salem, 636010, Tamil Nadu, India.
Bioprocess Biosyst Eng. 2016 Sep;39(9):1401-8. doi: 10.1007/s00449-016-1616-7. Epub 2016 Apr 29.
In this study, a simple and green method has been demonstrated for the synthesis of highly stable silver nanoparticles (AgNPs) using aqueous extract of Caulerpa racemosa (C. racemosa) as a reducing and capping agent. The formation and stability of AgNPs were studied using visual observation and UV-Visible (UV-Vis) spectroscopy. The stable AgNPs were further characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and high resolution transmission electron microscopy (HR-TEM) with energy dispersive spectroscopic (EDS) methods. The biosynthesized AgNPs showed a sharp surface plasmon resonance peak at 441 nm in the visible region and they have extended stability which has been confirmed by the UV-Vis spectroscopic results. XRD result revealed the crystalline nature of synthesized AgNPs and they are mainly oriented in (111) plane. FT-IR studies proved that the phytoconstituents of C. racemosa protect the AgNPs from aggregation and also which are responsible for the high stability. The size of synthesized AgNPs was approximately 25 nm with distorted spherical shape, identified from the HR-TEM images. The synthesized AgNPs showed excellent catalytic activity towards degradation of methylene blue.
在本研究中，已证明一种简单且绿色的方法，即使用总状蕨藻（C. racemosa）水提取物作为还原剂和封端剂来合成高度稳定的银纳米颗粒（AgNPs）。通过肉眼观察和紫外可见（UV-Vis）光谱研究了AgNPs的形成和稳定性。采用X射线衍射（XRD）、傅里叶变换红外（FT-IR）光谱以及配有能谱（EDS）方法的高分辨率透射电子显微镜（HR-TEM）对稳定的AgNPs进行了进一步表征。生物合成的AgNPs在可见光区域441 nm处显示出尖锐的表面等离子体共振峰，并且紫外可见光谱结果证实了它们具有持久的稳定性。XRD结果揭示了合成的AgNPs的晶体性质，且它们主要沿（111）面取向。FT-IR研究证明，总状蕨藻的植物成分可保护AgNPs不发生聚集，这也是其具有高稳定性的原因。从HR-TEM图像可知，合成的AgNPs尺寸约为25 nm，形状为扭曲的球形。合成的AgNPs对亚甲基蓝的降解表现出优异的催化活性。
