Ajitha B, Ashok Kumar Reddy Y, Sreedhara Reddy P
Department of Physics, Sri Venkateswara University, Tirupati 517502, India.
Department of Electrical Engineering, Korea Advanced Institute of Science and Technology, 335 Gwahangno, Yuseong-gu, Daejeon 305-701, South Korea.
Spectrochim Acta A Mol Biomol Spectrosc. 2014 Jul 15;128:257-62. doi: 10.1016/j.saa.2014.02.105. Epub 2014 Mar 7.
This study reports the simple green synthesis method for the preparation of silver nanoparticles (Ag NPs) using Plectranthus amboinicus leaf extract. The pathway of nanoparticles formation is by means of reduction of AgNO3 by leaf extract, which acts as both reducing and capping agents. Synthesized Ag NPs were subjected to different characterizations for studying the structural, chemical, morphological, optical and antimicrobial properties. The bright circular fringes in SAED pattern and diffraction peaks in XRD profile reveals high crystalline nature of biosynthesized Ag NPs. Morphological studies shows the formation of nearly spherical nanoparticles. FTIR spectrum confirms the existence of various functional groups of biomolecules capping the nanoparticles. UV-visible spectrum displays single SPR band at 428 nm indicating the absence of anisotropic particles. The synthesized Ag NPs exhibited better antimicrobial property towards gram negative Escherichia coli and towards tested Penicillium spp. than other tested microorganisms using disc diffusion method. Finally it has proven that the synthesized bio-inspired Ag NPs have potent antimicrobial effect.
本研究报道了一种使用食用霍香叶提取物制备银纳米颗粒（Ag NPs）的简单绿色合成方法。纳米颗粒的形成途径是通过叶提取物还原硝酸银，叶提取物同时充当还原剂和封端剂。对合成的Ag NPs进行了不同的表征，以研究其结构、化学、形态、光学和抗菌性能。SAED图谱中的明亮圆形条纹和XRD图谱中的衍射峰表明生物合成的Ag NPs具有高结晶性。形态学研究显示形成了近球形的纳米颗粒。FTIR光谱证实了覆盖纳米颗粒的生物分子中各种官能团的存在。紫外可见光谱在428 nm处显示单一的SPR带，表明不存在各向异性颗粒。使用纸片扩散法，合成的Ag NPs对革兰氏阴性大肠杆菌和受试青霉属菌株显示出比其他受试微生物更好的抗菌性能。最后证明，合成的生物启发型Ag NPs具有强大的抗菌作用。
