title: Phytoproteins in green leaves as building blocks for photosynthesis of gold nanoparticles: An efficient electrocatalyst towards the oxidation of ascorbic acid and the reduction of hydrogen peroxide.
abstract: Herein, we present a simple and green method for the synthesis of gold nanoparticles (AuNPs) using the phytoproteins of spinach leaves. Under ambient sunlight irradiation, the isolated phytoprotein complex from spinach leaves reduces the gold chloride aqueous solution and stabilizes the formed AuNPs. As prepared nanoparticles were characterized by UV-visible spectroscopy, Fourier transform infra-red (FTIR) spectroscopy, zeta potential, transmission electron microscopy (TEM) and energy dispersive X-ray analysis (EDS). The surface plasmon resonance (SPR) maximum for AuNPs was observed at 520 nm. The zeta potential value estimated for the AuNPs is -27.0 mV, indicating that the NPs are well separated. Transmission electron micrographs revealed that the particles are spherical in nature with the size range from 10 to 15 nm. AuNPs act as a catalyst in the degradation of an azo dye, methyl orange in an aqueous environment. The reduction rate was determined to be pseudo-first order. Electrocatalytic efficiency of the synthesized AuNPs via this green approach was studied by chronoamperometry using ascorbic acid and hydrogen peroxide as a model compound for oxidation and reduction, respectively. Electrocatalytic studies indicate that the gold nanoparticles can be used to detect ascorbic acid and hydrogen peroxide in micromolar concentrations with response time less than 3s.
authors.affiliation: Department of Chemistry, School of Chemical and Biotechnology, SASTRA University, Thanjavur 613 401, Tamil Nadu, India.
authors.forename: Sengan
authors.initials: S
authors.lastname: Megarajan
authors.affiliation: Department of Chemistry, School of Chemical and Biotechnology, SASTRA University, Thanjavur 613 401, Tamil Nadu, India.
authors.forename: Khan Behlol
authors.initials: KB
authors.lastname: Ayaz Ahmed
authors.affiliation: Department of Chemistry, School of Chemical and Biotechnology, SASTRA University, Thanjavur 613 401, Tamil Nadu, India.
authors.forename: G
authors.initials: G
authors.lastname: Rajendra Kumar Reddy
authors.affiliation: Department of Chemistry, School of Chemical and Biotechnology, SASTRA University, Thanjavur 613 401, Tamil Nadu, India.
authors.forename: P
authors.initials: P
authors.lastname: Suresh Kumar
authors.affiliation: Department of Chemistry, School of Chemical and Biotechnology, SASTRA University, Thanjavur 613 401, Tamil Nadu, India. Electronic address: anbazhagan@scbt.sastra.edu.
authors.forename: Veerappan
authors.initials: V
authors.lastname: Anbazhagan
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry; D002384:Catalysis; D055664:Electrochemical Techniques; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D055772:Green Chemistry Technology; D006861:Hydrogen Peroxide / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D010316:Particle Size; D010788:Photosynthesis / Q000528:radiation effects; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism; D018724:Spinacia oleracea / Q000378:metabolism
chemical_list: D001391:Azo Compounds; D010940:Plant Proteins; C100258:methyl orange; D006046:Gold; D006861:Hydrogen Peroxide; D001205:Ascorbic Acid
keywords: Dye degradation; Electrocatalyst; Gold nanoparticles; Green synthesis; Phytoproteins