title: Preparation and characterization of bio-nanocomposite films of agar and silver nanoparticles: laser ablation method.
abstract: Silver nanoparticles (AgNPs) were prepared by a laser ablation method and composite films with the AgNPs and agar were prepared by solvent casting method. UV-vis absorbance test and transmission electron microscopy (TEM) analysis results revealed that non-agglomerated spherical AgNPs were formed by the laser ablation method. The surface color of the resulting agar/AgNPs films exhibited the characteristic plasmonic effect of the AgNPs with the maximum absorption peaks of 400-407 nm. X-ray diffraction (XRD) test results also exhibited characteristic AgNPs crystals with diffraction peaks observed at 2θ values of 38.39°, 44.49°, and 64.45°, which were corresponding to (111), (200), and (220) crystallographic planes of face-centered cubic (fcc) silver crystals, respectively. Thermogravimetric analysis (TGA) results showed that thermal stability of the agar/AgNPs composite films was increased by the inclusion of metallic silver. Water vapor barrier properties and surface hydrophobicity of the agar/AgNPs films increased slightly with the increase in AgNPs content but they were not statistically significant (p>0.05), while mechanical strength and stiffness of the composite films decreased slightly (p<0.05). The agar/AgNPs films exhibited distinctive antimicrobial activity against both Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli O157:H7) bacterial pathogens.
authors: Department of Food Engineering and Bionanocomposite Research Institute, Mokpo National University, 61 Dorimri, Chungkyemyon, Muangun, 534-729 Jeonnam, Republic of Korea. Electronic address: jwrhim@mokpo.ac.kr.
authors: Jong-Whan
authors: JW
authors: Rhim
authors: Department of Food Engineering and Bionanocomposite Research Institute, Mokpo National University, 61 Dorimri, Chungkyemyon, Muangun, 534-729 Jeonnam, Republic of Korea.
authors: Long-Feng
authors: LF
authors: Wang
authors: Department of Chemistry, Mokpo National University, 61 Dorimri, Chungkyemyon, Muangun, 534-729 Jeonnam, Republic of Korea.
authors: Yonghoon
authors: Y
authors: Lee
authors: Korea Food Research Institute, 516 Baekhyun-dong, Bundang-gu, Seongnam-si, 463-746 Gyonggi-do, Republic of Korea.
authors: Seok-In
authors: SI
authors: Hong
mesh_terms: D000362:Agar / Q000737:chemistry / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D019453:Escherichia coli O157 / Q000187:drug effects*; D007834:Lasers; D008089:Listeria monocytogenes / Q000187:drug effects*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D012834:Silver / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D012834:Silver; D000362:Agar
keywords: Agar; Antimicrobial activity; Bio-nanocomposites; Laser ablation; Silver nanoparticles