title: A versatile effect of chitosan-silver nanocomposite for surface plasmonic photocatalytic and antibacterial activity.
abstract: Chitosan-silver (CS-Ag) nanocomposite was green synthesised without the aid of any external chemical-reducing agents. The synthesised nanocomposite was characterised by UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), high-resolution transmission electron microscopy (HR-TEM) with selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), and zeta potential analyser. The particle size of the synthesised CS-Ag nanocomposite was around 20 nm and was found to be thermally stable in comparison with pure chitosan. The prepared nanocomposite acts as a photocatalyst for dye decolourisation, with a maximum of 81% of methyl orange (MO) decolourisation that occurred under visible light irradiation. The kinetics was found to follow pseudo-first-order according to Langmuir-Hinshelwood (L-H) model. The nanocomposite also proved to be an excellent antimicrobial agent against both Gram-positive and Gram-negative bacteria, possessing a broad spectrum of antimicrobial activity. The zone of inhibition ranged between 16.000 ± 1.000 and 19.333 ± 1.155 (mm), proving its high susceptibility than chitosan itself. The minimum inhibitory concentration (MIC) values were from 8 to 64 μg/mL, whereas the minimum bactericidal concentration (MBC) values ranged from 16 to 128 μg/mL, with the highest antibacterial activity shown against Gram-positive Staphlococcus aureus. This report illustrates the eco-friendly approach for the reduction of silver using chitosan as a reducing agent, and its potential to dye decay and microbial contaminants.
authors.affiliation: Department of Chemistry, Bharathidasan Institute of Technology, Anna University, Tiruchirappalli 620024, Tamil Nadu, India.
authors.forename: Arjunan
authors.initials: A
authors.lastname: Nithya
authors.affiliation: National Facility for Drug Development (NFDD) for Academia, Pharmaceutical and Allied Industries, Bharathidasan Institute of Technology, Anna University, Tiruchirappalli 620024, Tamil Nadu, India; Department of Pharmaceutical Technology, Centre for Excellence in Nanobio Translational Research (CENTRE), Bharathidasan Institute of Technology, Anna University, Tiruchirappalli 620024, Tamil Nadu, India.
authors.forename: Henry Linda
authors.initials: HL
authors.lastname: JeevaKumari
authors.affiliation: Department of Chemistry, Bharathidasan Institute of Technology, Anna University, Tiruchirappalli 620024, Tamil Nadu, India.
authors.forename: Karuppannan
authors.initials: K
authors.lastname: Rokesh
authors.affiliation: National Facility for Drug Development (NFDD) for Academia, Pharmaceutical and Allied Industries, Bharathidasan Institute of Technology, Anna University, Tiruchirappalli 620024, Tamil Nadu, India; Department of Pharmaceutical Technology, Centre for Excellence in Nanobio Translational Research (CENTRE), Bharathidasan Institute of Technology, Anna University, Tiruchirappalli 620024, Tamil Nadu, India.
authors.forename: Kandasamy
authors.initials: K
authors.lastname: Ruckmani
authors.affiliation: Centre for Nanoscience and Nanotechnology, School of Physics, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India.
authors.forename: Kulandaivel
authors.initials: K
authors.lastname: Jeganathan
authors.affiliation: Department of Chemistry, Bharathidasan Institute of Technology, Anna University, Tiruchirappalli 620024, Tamil Nadu, India. Electronic address: jothivenkat@yahoo.com.
authors.forename: Kandasamy
authors.initials: K
authors.lastname: Jothivenkatachalam
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D001391:Azo Compounds / Q000737:chemistry; D002384:Catalysis; D048271:Chitosan / Q000737:chemistry*; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000528:radiation effects; D006094:Gram-Positive Bacteria / Q000187:drug effects* / Q000528:radiation effects; D006863:Hydrogen-Ion Concentration; D008027:Light; D008826:Microbial Sensitivity Tests; D018625:Microscopy, Atomic Force; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D012834:Silver / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D001391:Azo Compounds; D012834:Silver; C100258:methyl orange; D048271:Chitosan
keywords: Antimicrobial activity; Chitosan-silver nanocomposite; Minimum bactericidal concentration; Minimum inhibitory concentration; Photocatalysis