Institute of Environmental Science & Research Ltd. ESR

Porirua, New Zealand

Institute of Environmental Science & Research Ltd. ESR

Porirua, New Zealand
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Pang L.,Institute of Environmental Science & Research Ltd ESR | Robson B.,Institute of Environmental Science & Research Ltd ESR | Farkas K.,Institute of Environmental Science & Research Ltd ESR | Farkas K.,University of Canterbury | And 6 more authors.
Science of the Total Environment | Year: 2017

With the intensification of human activities, fresh water resources are increasingly being exposed to contamination from effluent disposal to land. Thus, there is a greater need to identify the sources and pathways of water contamination to enable the development of better mitigation strategies. To track discharges of domestic effluent into soil and groundwater, 10 synthetic double-stranded DNA (dsDNA)3 tracers were developed in this study. Laboratory column experiment and field groundwater and soil lysimeter studies were carried out spiking DNA with oxidation-pond domestic effluent. The selected DNA tracers were compared with a non-reactive bromide (Br) tracer with respect to their relative mass recoveries, speeds of travel and dispersions using the method of temporal moments. In intact stony soil and gravel aquifer media, the dsDNA tracers typically showed earlier breakthrough and less dispersion than the Br tracer, and underwent mass reduction. This suggests that the dsDNA tracers were predominantly transported through the network of larger pores or preferential flow paths. Effluent tracking experiments in soil and groundwater demonstrated that the dsDNA tracers were readily detectable in effluent-contaminated soil and groundwater using quantitative polymerase chain reaction. DNA tracer spiked in the effluent at quantities of 36 μg was detected in groundwater 37 m down-gradient at a concentration 3-orders of magnitude above the detection limit. It is anticipated it could be detected at far greater distances. Our findings suggest that synthetic dsDNA tracers are promising for tracking effluent discharges in soils and groundwater but further studies are needed to investigate DNA-effluent interaction and the impact of subsurface environmental conditions on DNA attenuation. With further validation, synthetic dsDNA tracers, especially when multiple DNA tracers are used concurrently, can be an effective new tool to track effluent discharge in soils and groundwater, providing spatial estimation on the presence or absence of contamination sources and pathways. © 2017 Elsevier B.V.

PubMed | University of Technology, Sydney and Institute of Environmental Science & Research ESR Ltd
Type: | Journal: Forensic science international | Year: 2014

Variation in the chemical composition of illicit tablets and powders is common among samples within a given drug seizure. Using microchip electrophoresis (ME), multiple tablets can be screened in a cost-effective and timely manner. This method could be used in conjunction with reporting methods that focus solely on statistical sampling to infer homogeneity or otherwise of a larger subset of tablets. Some frequently observed synthetic cathinones, often present in illicit tablets seized in New Zealand, were chosen for analysis. An ME device (Agilent Bioanalyzer 2100) was used to electrophoretically separate synthetic cathinones. The background electrolyte was composed of a 50 mM sodium tetraborate buffer with 50 mM sodium dodecyl sulphate at pH 9.66. Analytes were derivatised prior to analysis for 3 min at 90C, employing fluorescein isothiocyanate isomer I (FITC). A characteristic fluorescent profile was obtained for each tablet, in terms of the number of constituents, relative peak height ratios and migration times. The repeatability of the developed method was assessed for a wide range of tablets and relative standard deviations of 0.4-5.2% and 1.6-5.5% were calculated for migration times and peak height ratios, respectively. The use of microchip tablet profiles in the forensic case comparison of illicit drug seizure samples in realistic scenarios is discussed.

Booth M.A.,University of Auckland | Booth M.A.,Institute of Environmental Science Research Ltd. ESR | Leveneur J.,University of Auckland | Leveneur J.,Institute of Geological & Nuclear Sciences | And 5 more authors.
Journal of Physical Chemistry C | Year: 2012

Low-energy platinum ions were implanted with 15 keV under normal incidence into synthesized conducting polymer films with the aim to improve film conductivity and to demonstrate the use of implanted platinum in a simple sensing design. Conductivity measurements, cyclic voltammetry, and Raman spectroscopy were performed on samples both before and following ion implantation. Results display an optimum fluence of ion implantation for which polypyrrole films implanted with 2 × 10 16 at. cm -2 display and retain enhanced conductivity compared with nonimplanted samples. X-ray photoelectron spectroscopy (XPS) and scanning electron microscope-energy-dispersive X-ray spectroscopy (SEM-EDS) confirmed that implanted platinum is present mainly as Pt 0 and indicated that the depth and amount of ion implantation are in agreement with a simulated implantation profile. Raman spectroscopy showed a surface-enhanced Raman spectroscopy (SERS) effect with platinum's presence. The advantageous increase in conductivity can be rationalized by two chemical modifications to the polymer upon high-fluence implantation: (1) an increase in the number of charge carriers (dications) within the polymer and (2) the presence of elemental platinum metal and its synergistic effect on conductivity. A simple DNA sensor was constructed on the basis of polypyrrole/Pt 0 films where Pt 0 was able to serve as anchoring points for DNA attachment as well as an enhancer of the film's conductivity. This enabled a DNA sensor capable of successful detection of cDNA, and a good discrimination of noncDNA, thus opening a way to direct electrochemical biosensing on the basis of ion implanted highly conducting polymer films. © 2012 American Chemical Society.

Kaas L.,Institute of Environmental Science & Research Ltd. ESR | Gourinat A.-C.,Institute Pasteur Of Nouvelle Caledonie | Urbes F.,Institute Pasteur Of Nouvelle Caledonie | Langlet J.,Institute of Environmental Science & Research Ltd. ESR
Food and Environmental Virology | Year: 2016

Human enteric viruses occur in high concentrations in wastewater and can contaminate receiving environmental waters. Due to the lack of data on the prevalence of enteric viruses in New Caledonia, the presence and the concentrations of enteric viruses in wastewater and seawater were determined. Untreated wastewater and seawater samples were collected monthly for 1 year from a wastewater treatment plant (WWTP) and from the WWTP’s outlet, located directly on a popular recreational beach. Samples were tested for norovirus genogroups I and II (NoV GI and GII), astroviruses (AsV), sapoviruses (SaV), enteroviruses (EV), hepatitis A viruses (HAV), rotaviruses (RoV), human adenoviruses (HAdV) and human polyomaviruses (HPyV). To support these data, faecal samples from cases of gastroenteritis were tested for the first time for NoV and detected in the population. NoV GI, NoV GII, EV, SaV, HAdV and HPyV were detected in all wastewaters, RoV in 75 % and AsV in 67 %. HAV were not detected in wastewater. Overall, 92 % of seawater samples were positive for at least one virus. HPyV were detected most frequently in 92 % of samples and at concentrations up to 7.7 × 103 genome copies/L. NoV GI, NoV GII, EV, SaV, RoV and HAdV were found in 33, 66, 41, 33, 16 and 66 % of seawater samples, respectively. AsV were not detected in seawater. This study reports for the first time the presence of NoV and other enteric viruses in New Caledonia and highlights the year-round presence of enteric viruses in the seawater of a popular beach. © 2015, Springer Science+Business Media New York.

Booth M.A.,University of Auckland | Harbison S.,Institute of Environmental Science Research Ltd. ESR | Travas-Sejdic J.,University of Auckland | Travas-Sejdic J.,MacDiarmid Institute for Advanced Materials and Nanotechnology
Electroanalysis | Year: 2012

Much research-to-date exists to create sensitive and selective DNA sensors. A variety of approaches are adopted, including those involving polypyrrole and electrical impedance spectroscopy. Combined these are able to sense as well as aptly transduce signals. Many such sensors employ ferri/ferrocyanide to exhibit surface hybridization. This redox reporter, though with merits, can prove disadvantageous. To this end, a comparative study was performed with the redox reporter hydroquinone. For comparison purposes ferri/ferrocyanide indicated greater sensitivity, suggested to arise from inherent charge. Conversely, with hydroquinone steric hindrance is the main influencing factor. Such a study aims to guide design of analogous sensors. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Adela Booth M.,University of Auckland | Adela Booth M.,Institute of Environmental Science Research Ltd. ESR | Vogel R.,Izon Science Ltd. | Vogel R.,University of Queensland | And 4 more authors.
Biosensors and Bioelectronics | Year: 2013

Despite the plethora of DNA sensor platforms available, a portable, sensitive, selective and economic sensor able to rival current fluorescence-based techniques would find use in many applications. In this research, probe oligonucleotide-grafted particles are used to detect target DNA in solution through a resistive pulse nanopore detection technique. Using carbodiimide chemistry, functionalised probe DNA strands are attached to carboxylated dextran-based magnetic particles. Subsequent incubation with complementary target DNA yields a change in surface properties as the two DNA strands hybridize. Particle-by-particle analysis with resistive pulse sensing is performed to detect these changes. A variable pressure method allows identification of changes in the surface charge of particles. As proof-of-principle, we demonstrate that target hybridization is selectively detected at micromolar concentrations (nanomoles of target) using resistive pulse sensing, confirmed by fluorescence and phase analysis light scattering as complementary techniques. The advantages, feasibility and limitations of using resistive pulse sensing for sample analysis are discussed. © 2013 Elsevier B.V.

Booth M.A.,University of Auckland | Booth M.A.,Institute of Environmental Science Research Ltd. ESR | Harbison S.,Institute of Environmental Science Research Ltd. ESR | Travas-Sejdic J.,Institute of Environmental Science Research Ltd. ESR | Travas-Sejdic J.,MacDiarmid Institute for Advanced Materials and Nanotechnology
Biosensors and Bioelectronics | Year: 2011

DNA sensors have a wide scope of applications in the present and emerging medical and scientific fields, such as medical diagnostics and forensic investigations. However, much research-to-date on DNA sensor development has focused on short target DNA strands as model genes. In this communication we study the effect of the length of oligonucleotide probe and target strands as a significant step towards real world applications for DNA detection. The sensor technology described uses the conducting polymer polypyrrole as both a sensing element and transducer of sensing events - namely the hybridization of complementary target oligonucleotide to probe oligonucleotide. Detection is performed using electrical impedance spectroscopy. Initially sensor development is performed, wherein we demonstrate an improvement in stability and sensitivity as well as show a reduction in non-specific DNA binding for fabricated sensors, through use of a specific dopant and post-growth treatment. Subsequently, we show that longer target DNA strands display increased response, as do sensors containing longer probe DNA strands. It is suggested that these results are a feature of the increase in negative charges associated with the longer DNA strands. The results of this comparative study are aimed to guide future design of analogous sensors. © 2011 Elsevier B.V.

Booth M.A.,University of Auckland | Booth M.A.,Institute of Environmental Science Research Ltd. ESR | Leveneur J.,University of Auckland | Leveneur J.,Institute of Geological & Nuclear Sciences | And 7 more authors.
Materials Chemistry and Physics | Year: 2012

Interest lies in the creation of novel nanocomposite materials obtained through mixing, impregnation or incorporation techniques. One such technique is ion implantation which possesses the potential for retaining properties from the base material and implanted material as well as any effects observed from combining the two. To this end low-energy (15 keV) implantation of lead ions of various fluences was performed in conducting polypyrrole films. The presence of lead-rich particles was evidenced through transmission electron microscopy. An interesting trend was observed between fluence and conductivity. Of the fluences tested, the optimum fluences of lead ion implantation in polypyrrole films for enhanced conductivity are 5 × 10 14 at. cm -2 and 2 × 10 15 at. cm -2. The conductivity and stability appear to result from a combination of effects: polymer degradation arising from ion beam damage, an increase in charge-carriers (dications) present after implantation and precipitation of Pb-rich nanoparticles. Monitoring conductivity over time showed increased retention of conductivity levels after lead implantation. Improvements in stability for polypyrrole open avenues for application and bring polypyrrole one step closer to practical use. A mechanism is suggested for this advantageous retained conductivity. © 2012 Elsevier B.V. All rights reserved.

Institute of Environmental Science & Research Ltd ESR | Date: 2016-06-28

Computer software for interpretation of DNA profiling results. Printed instructional and teaching material, not including apparatus, relating to computer software for interpretation of DNA profiling results.

PubMed | Institute of Environmental Science & Research ESR Ltd
Type: Journal Article | Journal: Journal of forensic sciences | Year: 2015

The delivery of forensic science evidence in a clear and understandable manner is an important aspect of a forensic scientists role during expert witness delivery in a courtroom trial. This article describes an Integrated Evidence Platform (IEP) system based on spherical photography which allows the audience to view the crime scene via a virtual tour and view the forensic scientists evidence and results in context. Equipment and software programmes used in the creation of the IEP include a Nikon DSLR camera, a Seitz Roundshot VR Drive, PTGui Pro, and Tourweaver Professional Edition. The IEP enables a clear visualization of the crime scene, with embedded information such as photographs of items of interest, complex forensic evidence, the results of laboratory analyses, and scientific opinion evidence presented in context. The IEP has resulted in significant improvements to the pretrial disclosure of forensic results, enhanced the delivery of evidence in court, and improved the jurys understanding of the spatial relationship between results.

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