title: Accumulation and phytotoxicity of engineered nanoparticles to Cucurbita pepo.
abstract: The effect of bulk and engineered nanoparticle (NP) Ag, Au, Cu, Si, and C at 250 and 750 mg/L on zucchini biomass, transpiration, and element content was determined. The pH of bulk and NP solutions prior to plant growth frequently differed. Nanoparticle Cu solution pH was significantly higher than bulk Cu, whereas for Ag and C, the NPs had significantly lower pH. Plants were unaffected by Au, regardless of particle size or concentration. NP Ag reduced plant biomass and transpiration by 49-91% compared to equivalent bulk Ag. NP Si at 750 mg/L reduced plant growth and transpiration by 30-51% relative to bulk Si. Bulk and NP Cu were phytotoxic but much of the effect was alleviated by humic acid. The shoot Ag and Cu content did not differ based on particle size or concentration. The accumulation of bulk Au was greater than the NP, but humic acid increased the accumulation of NP and bulk Au by 5.6-fold and 80%, respectively. The uptake of NP Si was 5.6-6.5-fold greater than observed with the bulk element. These findings show that the NPs may have unique phytotoxicity or accumulation patterns and that solution properties can significantly impact particle fate and effects.
authors.affiliation: Department of Analytical Chemistry, The Connecticut Agricultural Experiment Station, New Haven, Connecticut 06511, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Hawthorne
authors.forename: Craig
authors.initials: C
authors.lastname: Musante
authors.forename: Saion K
authors.initials: SK
authors.lastname: Sinha
authors.forename: Jason C
authors.initials: JC
authors.lastname: White
mesh_terms: D001681:Biological Assay; D018533:Biomass; D002244:Carbon / Q000378:metabolism / Q000633:toxicity; D002614:Chelating Agents; D003300:Copper / Q000378:metabolism / Q000633:toxicity; D028464:Cucurbita / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism*; D006046:Gold / Q000378:metabolism / Q000633:toxicity; D006812:Humic Substances; D006863:Hydrogen-Ion Concentration; D018527:Hydroponics; D053758:Nanoparticles / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D036103:Nanotechnology; D010316:Particle Size; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018526:Plant Transpiration / Q000187:drug effects*; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D012825:Silicon / Q000378:metabolism / Q000633:toxicity; D012834:Silver / Q000378:metabolism / Q000633:toxicity; D012996:Solutions; D013997:Time Factors
chemical_list: D002614:Chelating Agents; D006812:Humic Substances; D012996:Solutions; D012834:Silver; D002244:Carbon; D006046:Gold; D003300:Copper; D012825:Silicon