title: Biosynthesis of silver fine particles and particles decorated with nanoparticles using the extract of Illicium verum (star anise) seeds.
abstract: Given the upsurge of new technologies based on nanomaterials, the development of sustainable methods to obtain functional nanostructures has become an imperative task. In this matter, several recent researches have shown that the biodegradable natural antioxidants of several plant extracts can be used simultaneously as reducing and stabilizing agents in the wet chemical synthesis of metallic nanoparticles, opening new opportunities to design greener synthesis. However, the challenge of these new techniques is to produce stable colloidal nanoparticles with controlled particle uniformity, size, shape and aggregation state, in similar manner than the well-established synthetic methods. In the present work, colloidal metallic silver nanoparticles have been synthesized using silver nitrate and extracts of Illicium verum (star anise) seeds at room temperature in a facile one-step procedure. The resulting products were colloidal suspensions of two populations of silver nanoparticles, one of them with particle sizes of few nanometers and the other with particles of tens of nm. Strikingly, the variation of the AgNO3/extract weight ratio in the reaction medium yielded to the variation of the spatial distribution of the nanoparticles: high AgNO3/extract concentration ratios yielded to randomly dispersed particles, whereas for lower AgNO3/extract ratios, the biggest particles appeared coated with the finest nanoparticles. This biosynthesized colloidal system, with controlled particle aggregation states, presents plasmonic and SERS properties with potential applications in molecular sensors and nanophotonic devices.
authors: Centro de Investigación en Ciencias Físico Matemáticas/Facultad de Ciencias Físico Matemáticas, Universidad Autónoma de Nuevo León, Av. Universidad S/N, San Nicolás de los Garza, 66450 Nuevo León, Mexico. Electronic address: carlos.lunacd@uanl.edu.mx.
authors: Carlos
authors: C
authors: Luna
authors: Centro de Investigación en Ciencias Físico Matemáticas/Facultad de Ciencias Físico Matemáticas, Universidad Autónoma de Nuevo León, Av. Universidad S/N, San Nicolás de los Garza, 66450 Nuevo León, Mexico.
authors: V H G
authors: VH
authors: Chávez
authors: Centro de Investigación en Ciencias Físico Matemáticas/Facultad de Ciencias Físico Matemáticas, Universidad Autónoma de Nuevo León, Av. Universidad S/N, San Nicolás de los Garza, 66450 Nuevo León, Mexico.
authors: Enrique Díaz
authors: ED
authors: Barriga-Castro
authors: Instituto de Ciencia de Materiales de Sevilla, CSIC-US, Avda. Americo Vespucio n° 49, Isla de la Cartuja, 41092 Sevilla, Spain.
authors: Nuria O
authors: NO
authors: Núñez
authors: Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Av. Universidad S/N, San Nicolás de los Garza, 66450 Nuevo León, Mexico.
authors: Raquel
authors: R
authors: Mendoza-Reséndez
mesh_terms: D029523:Illicium / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D010936:Plant Extracts / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman
chemical_list: D010936:Plant Extracts; D012834:Silver
keywords: Biosynthesis; Illicium verum; Plasmons; SERS; Silver nanoparticles