title: Tannic acid-mediated green synthesis of antibacterial silver nanoparticles.
abstract: The search for novel antibacterial agents is necessary to combat microbial resistance to current antibiotics. Silver nanoparticles (AgNPs) have been reported to be effective antibacterial agents. Tannic acid is a polyphenol compound from plants with antioxidant and antibacterial activities. In this report, AgNPs were prepared from silver ions by tannic acid-mediated green synthesis (TA-AgNPs). The reaction process was facile and involved mixing both silver ions and tannic acid. The absorbance at 423 nm in the UV-Visible spectra demonstrated that tannic acid underwent a reduction reaction to produce TA-AgNPs from silver ions. The synthetic yield of TA-AgNPs was 90.5% based on inductively coupled plasma mass spectrometry analysis. High-resolution transmission electron microscopy and atomic force microscopy images indicated that spherical-shaped TA-AgNPs with a mean particle size of 27.7-46.7 nm were obtained. Powder high-resolution X-ray diffraction analysis indicated that the TA-AgNP structure was face-centered cubic with a zeta potential of -27.56 mV. The hydroxyl functional groups of tannic acid contributed to the synthesis of TA-AgNPs, which was confirmed by Fourier transform infrared spectroscopy. The in vitro antibacterial activity was measured using the minimum inhibitory concentration (MIC) method. The TA-AgNPs were more effective against Gram-negative bacteria than Gram-positive bacteria. The MIC for the TA-AgNPs in all of the tested strains was in a silver concentration range of 6.74-13.48 μg/mL. The tannic acid-mediated synthesis of AgNPs afforded biocompatible nanocomposites for antibacterial applications.
authors.affiliation: College of Pharmacy, Inje University, 197 Inje-ro, Gimhae, Gyeongnam, 621-749, Republic of Korea.
authors.forename: Tae Yoon
authors.initials: TY
authors.lastname: Kim
authors.affiliation: National Creative Research Initiatives (NCRI) Center for Isogeometric Optimal Design, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-744, Republic of Korea.
authors.forename: Song-Hyun
authors.initials: SH
authors.lastname: Cha
authors.affiliation: National Creative Research Initiatives (NCRI) Center for Isogeometric Optimal Design, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-744, Republic of Korea.
authors.forename: Seonho
authors.initials: S
authors.lastname: Cho
authors.affiliation: College of Pharmacy, Inje University, 197 Inje-ro, Gimhae, Gyeongnam, 621-749, Republic of Korea. youmiep@inje.ac.kr.
authors.forename: Youmie
authors.initials: Y
authors.lastname: Park
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D055808:Drug Discovery; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D055772:Green Chemistry Technology / Q000379:methods*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D010084:Oxidation-Reduction; D010316:Particle Size; D012834:Silver / Q000737:chemistry* / Q000494:pharmacology*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013634:Tannins / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D000900:Anti-Bacterial Agents; D013634:Tannins; D012834:Silver
keywords: Antibacterial activity; Green synthesis; Silver nanoparticles; Tannic acid