title: Biosynthesis of lead nanoparticles by the aquatic water fern, Salvinia minima Baker, when exposed to high lead concentration.
abstract: Salvinia minima Baker is a small floating aquatic fern that is efficient for the removal and storage of heavy metals such as lead and cadmium. In this study, we report that lead removal by S. minima causes large accumulation of lead inside the cells in the form of nanoparticles (PbNPs). The accumulation pattern of lead was analyzed in both, submerged root-like modified fronds (here named "roots"), and in its aerial leaf-like fronds ("leaves"). Analysis by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM) confirmed the biosynthesis of PbNPs by the plant. In both, roots and leaves, PbNPs were found to accumulate almost exclusively at the cell wall and closely associated to the cell membrane. Two types of PbNPs shapes were found in cells of both tissues, those associated to the cell wall were quasi-spherical with 17.2±4.2 nm of diameter, while those associated to the cell membrane/cytoplasm were elongated. Elongated particles were 53.7±29.6 nm in length and 11.1±2.4 nm wide. Infrared spectroscopy (IR) results indicate that cellulose, lignin and pectin are the major components that may be acting as the reducing agents for lead ions; these findings strongly suggest the potential use of this fern to further explore the bio-assisted synthesis of heavy metal nanostructures.
authors.affiliation: Departamento de Microbiología, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Ensenada, Mexico.
authors.forename: E
authors.initials: E
authors.lastname: Castro-Longoria
authors.affiliation: Laboratorio de Fisiología Vegetal Molecular, Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, Mérida, Yucatán, Mexico.
authors.forename: K
authors.initials: K
authors.lastname: Trejo-Guillén
authors.affiliation: Universidad Autónoma del Estado de México (UAEMex), Centro Conjunto de Investigación en Química Sustentable (CCIQS), Toluca, Estado de México, Mexico.
authors.forename: A R
authors.initials: AR
authors.lastname: Vilchis-Nestor
authors.affiliation: Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México (UNAM), Mexico; División de Materiales Avanzados, Instituto Potosino de Ciencia y Tecnología (IPICYT), SLP, Mexico.
authors.forename: M
authors.initials: M
authors.lastname: Avalos-Borja
authors.affiliation: Laboratorio de Fisiología Vegetal Molecular, Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, Mérida, Yucatán, Mexico.
authors.forename: S B
authors.initials: SB
authors.lastname: Andrade-Canto
authors.affiliation: Laboratorio de Fisiología Vegetal Molecular, Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, Mérida, Yucatán, Mexico.
authors.forename: D A
authors.initials: DA
authors.lastname: Leal-Alvarado
authors.affiliation: Laboratorio de Fisiología Vegetal Molecular, Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, Mérida, Yucatán, Mexico. Electronic address: jorgesm@cicy.mx.
authors.forename: J M
authors.initials: JM
authors.lastname: Santamaría
mesh_terms: D059001:Aquatic Organisms / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D001673:Biodegradation, Environmental / Q000187:drug effects; D004781:Environmental Exposure; D029624:Ferns / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D007854:Lead / Q000302:isolation & purification / Q000633:toxicity*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D012996:Solutions; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D012996:Solutions; D007854:Lead
keywords: Heavy metals; Lead nanoparticles; Pb aqueous removal; Salvinia minima