The fungi Aureobasidium pullulans , Mortierella humilis , Trichoderma harzianum and Phoma glomerata were used to investigate the formation of selenium- and tellurium-containing nanoparticles during growth on selenium- and tellurium-containing media. Most organisms were able to grow on both selenium- and tellurium-containing media at concentrations of 1 mM resulting in extensive precipitation of elemental selenium and tellurium on fungal surfaces as observed by the red and black colour changes. Red or black deposits were confirmed as elemental selenium and tellurium, respectively. Selenium oxide and tellurium oxide were also found after growth of Trichoderma harzianum with 1 mM selenite and tellurite as well as the formation of elemental selenium and tellurium. The hyphal matrix provided nucleation sites for metalloid deposition with extracellular protein and extracellular polymeric substances localizing the resultant Se or Te nanoparticles. These findings are relevant to remedial treatments for selenium and tellurium and to novel approaches for selenium and tellurium biorecovery.

Matrix-dependent size modifications of iron oxide nanoparticles (Ferumoxytol) spiked into rat blood cells and plasma: Characterisation with TEM, AF4-UV-MALS-ICP-MS/MS and spICP-MS.

The coupling of flow field flow fractionation (FlFFF) with ICP-MS/MS for the fractionation and analysis of natural nanoparticles in environmental samples is becoming more popular. However, the applicability of this technique to non-aqueous samples such as gas condensates from petroleum hydrocarbon samples has not been reported yet. In this study, an asymmetric flow-field flow fractionation (AF4) system coupled with UV and MALS detectors has been optimized to perform the fractionation of natural nanoparticles present in a gas condensate sample, using THF as the carrier liquid. Prior to this, STEM images indicated the presence of both large (200 nm and more) and smaller (50 nm and less) particles, whose irregular shape is probably due to agglomeration. AF4-UV-MALS-ICP-MS/MS confirmed the presence of various nanoparticles and colloids, some containing aromatic compounds as well as various metals including Hg. The recovery against an injection without crossflow is around 75% for most metals. The presence of Hgcontaining nanoparticles was confirmed with offline single particle ICP-MS (spICP-MS), using THF as a solvent. These NPs were identified as HgS using STEM-EDX. These results highlight for the first time that particulate matter may contaminate gas condensates with a series of elements (Al,

Cu 0 (core)-Au 0 (shell) (Cu@Au) bimetallic nanoparticles (NPs) synthesized under microwaveassisted heating were interrogated for surface enhanced Raman scattering (SERS)-active substrates. NPs characterization, by XRD, XPS and UV/vis spectroscopy, showed the formation of self-assembled particles with the occurrence of electron transfer from Cu to Au and the absence of CuxO. TEM and AF4 demonstrated NPs with a mean diameter of 4.7 nm. Despite the low LSPR shown by small nanoparticles (< 10 nm diameter), our Cu@Au NPs showed enhanced SERS effect, demonstrated by the calculated scattering signal enhancement factor (3 x 10 5 ), which may be related to electromagnetic coupling. Selected examples of analytes of interest, including some biomolecules, were studied to demonstrate the versatility of our Cu@Au NPs as SERS-active substrates.

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Targeted radiotherapy is proving to be an effective alternative to external beam radiotherapy for cancer treatment. Gold nanoparticles are bio-compatible, commercially available and readily functionalised, which makes them perfect candidates for the delivery of cytotoxic radionuclides labelled with antibodies to proteins abnormally expressed on cancer tissue. However, there is a lack of information regarding the efficacy of the successive modification steps involved in the functionalisation process, as well as of the actual final state of the nanoparticles prior to preclinical tests, which results in a very inefficient screening and that will further impact on biological barriers, such as half-life interactions with serum proteins. Here, gold nanoparticles (15 nm diameter) were functionalised with linkers for antibody and radionuclide conjugation, following a well-stablished method. Successful coating of the gold nanoparticles was demonstrated using state-of-the-art physico-chemical techniques, which include TEM, AF4-UV-ICPMS-MALS, Raman spectroscopy and force-distance spectroscopy, which have led to an accurate description of the hydrodynamic diameter of the functionalized NPs and also about the adhesion energy and elastic properties of the modified NPs. Successive steps involved in the coating led to an organic shell of 12 nm diameter and no nanoparticle aggregation was observed. This may be a consequence of a decrease (or even the total absence) of water adsorption on the metal surface and/or of the organic labelling, that decreases the surface tension of the particles as estimated from the atomic force microscopy force-distance curves. Radiolabelling of gold nanoparticles pre-screened using these physico-chemical tools with 177 Lu resulted in > 75% efficiency.

Diisocyanates have long been a leading cause of occupational asthma. As control often relies on personal protective equipment and there is the potential for skin uptake, biological monitoring is often used to assess worker exposure. Current routine biological monitoring methods do not distinguish between a diisocyanate and the corresponding diamine exposure in urine samples; therefore, a specific urinary biomarker is desirable. Urine samples were obtained from a group of workers exposed to methylenediphenyl diisocyanate (MDI) where aerosol generation was unlikely. Lysine conjugates of MDI were extracted from urine by solid phase extraction; analysis was performed by liquid chromatography tandem mass spectrometry. Acetylated MDI-lysine (acMDI-Lys) conjugates were detected in 73% of samples tested from persons with exposure to MDI compared to 93% of samples that were positive for methylene dianiline (MDA) in hydrolysed urine. There was a weak but significant positive correlation between the two biomarkers (r2 = 0.377). This is the first report detecting and quantifying acMDI-Lys in the urine of workers exposed to MDI, and acMDI-Lys may be a useful non-invasive biomarker in discriminating between MDI and MDA exposures.

Samples of Bowland Shale and equivalents in Ireland, representing a range of thermal maturities from oil window to gas window, contain trace elements distributed through multiple residences. The trace element distribution reflects the depositional environment, and influences subsequent element release. Measurements of Se, Cu, As, U and Mo indicate variable retention in loosely-bound and strongly-bound forms. The trace elements are especially associated with diagenetic pyrite. Shales from Ireland, at higher thermal maturity, have relatively high proportions of loosely-bound Se, Cu and As, which may reflect expulsion from the pyrite during recrystallization. The shale samples consistently contain high contents of organic matter, reflecting deposition in an anoxic environment. The Se, Mo and U in particular may be bound to organic matter, which may have adverse environmental impacts upon weathering of the shale.