NanoFASE - nanofase-case-study-stable-isotope-tracing-of-silver-nanoparticles-in-wheat

Silver nanoparticles (Ag NPs) can enter natural ecosystems by direct application or by release from products, or when Ag NPs from wastewater streams are captured in sewage sludge and applied on agricultural land as biosolid fertilisers. Ag NPs have been reported to be taken up by plants through the root and therefore it is important to understand the patterns of accumulation and translocation of Ag NPs in plants, particularly at environmentally relevant exposure concentrations. In this study, isotopically labelled ¹⁰⁹Ag NPs were used to expose plants to Ag concentrations to assess accumulation in the crop plant wheat, Triticum aestivum.

Study aim

The aim of this study was to quantify uptake of Ag NPs and Ag+ from isotopically labelled ¹⁰⁹Ag by wheat plants at environmentally relevant concentrations using a stable isotope approach.

Experimental approach

Overview

Stable Ag isotope nanoparticles are synthesised (¹⁰⁹Ag NP)
Soil is spiked with ¹⁰⁹Ag NPs
Winter wheat is grown to maturity in the spiked soil and samples are collected from the four treatment conditions at eight different biological plant growth stages
Digestion and column chemistry
Isotopic analysis with MC-ICPMS (multiple collector - inductively coupled plasma mass spectrometry) - measures both 109/107Ag ratio and ¹⁰⁹Ag concentrations

Compartment involved:

Soil

NP type/size:

Citrate coated Ag NPs - 20nm

Species:
Wheat (Triticum aestivum)

Bioassay:
Bioaccumulation assay
Extractable Ag assay

Results

No adverse effects for winter wheat exposed to Ag NPs & Ag⁺ at environmentally relevant concentrations were found.

The concentrations of Ag derived from NPs were highest in the roots and lowest in the grains.
Ag uptake by wheat was higher for nanoparticles than for dissolved Ag⁺ which is likely related to the greater soluble Ag in the pore water of the nanoparticle exposure.

Parameters

Bioaccumulation factor – BAF
Transfer function – TF
Pore water and soil concentrations
Fresh and dry biomass in time

Agricultural soil Wheat

Read also

Visit the NanoFASE Library to read summaries of these reports:

NanoFASE Report D7.2 Soil property – NM fate relationships

NanoFASE Report D9.2 Parameter sets on uptake and toxicokinetics of selected pristine NMs in aquatic and terrestrial organisms (summary of internal report)

OECD Test No. 208: Terrestrial Plant Test: Seedling Emergence and Seedling Growth Test

Laycock, A, Stolpe, B, Römer, I, Dybowska, A, Valsami-Jones, E, Lead, J.R., Rehkämper, M (2014) Synthesis and characterization of isotopically labeled silver nanoparticles for tracing studies ES Nano 1:3 271-283