RP13 Sensors for Environmental Monitoring|
Thursday, 17 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall
RP174 (KAW-1117-806036) Validation of a new-developed biosensor to evaluate genotoxicity and cytotoxicity of various environmental water samples.
Start time: 8:00 AM
Kawakami, M1, Shoji, R1, Ishii, H1, Tanaka, Y2, Taguchi, K2, Hirai, M3, Imaeda, T3, Yamada, M4, Inoue, Y4, Mohri, S5, 1 Tokyo National College of Technology, Hachioji, Tokyo, Japan2 Fuji Electric Advanced Technology Co., Ltd., Hino, Tokyo, Japan3 Toyoda Central R&D Labs., Inc., Nagakute, Aichi, Japan4 National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan5 Okayama University, Okayama, Okayama, Japan
The umu-lux test is a genotoxicity test using the two genetically modified S.typhmurium TA1535 strains (TL210 and TL210ctl) transformed with the luxCDABE (luciferase gene and fatty acid reductase genes) extracting from Vibrio fischeri as a reporter gene. The TL210 and TL210ctl can detect genotoxicity and cytotoxicity of exposed chemicals or samples, respectively. A rapid genotoxicity and cytotoxicity detection system using these two immobilized strains was developed. The immobilized strains could be activated in one hour. The biosensor system can evaluate genotoxicity of mutagens or waste water samples in about only four hours. Sensitivity for detecting genotoxicity was compared between the biosensor and conventional umu-test. Various types of wastewater such as extracts from waste incineration ashes, and industrial wastewater were applied to the biosensor for the genotoxicity testing. By using some typical genotoxicants, it is suggested that sensitivity of the biosensor was significantly better than that of the umu-test in terms of the genotoxicant concentration giving a signal to noise ratio (S/N) of 1. In addition to this advantage, the conventional Umu test can not directly detect genotoxicity of dyes or colored water samples because genotoxic response of the S.typhmurium used for the conventional method should be detected by absorbance of the culture solution. On the other hand, the biosensor using luminescence umu strain can directly detect genotoxicity of dyes and colored samples. It is concluded that the biosensor developed for detection of genotoxicity is a promising tool for environmental management in terms of human health carcinogenicity.
RP176 (LAZ-1119-112658) Adaptation of metal nanoparticle biosensors for identification of bio-inorganic interactions of relevance to colloidal assembly in natural waters.
Start time: 8:00 AM
Lazarides, A1, Miller, M1, 1 Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC, USA
Metal nanoparticles that support plasmon resonances at frequencies corresponding to the frequencies of visible light are being developed as biomolecule sensors for biotechnology applications. Because the resonant frequencies of the nanoparticles are sensitive to the presence of molecules on the surfaces of the particles, visible spectroscopy can be used to monitor the assembly of molecules on nanoparticle surfaces. We are investigating the application of nanoparticle-based molecule detection methods to environmental science, and in particular, to the study of the role of acid polysaccharides in colloidal particle aggregation and metal sequestration processes that lead to sedimentation and metal clearance from the water column in natural waters. Our substrate for sensing consists of an array of disk-shaped noble metal nanoparticles patterned on a transparent substrate. Spectra of the patterned substrate are routinely collected in transmission mode. The nanoparticles can be activated for mono- or polysaccharide functionalization through exposure to sugar-reactive molecules with terminal sulfer groups that form monolayers on the nanoparticle surface. Presentation of sugars or polysaccharides leads to chemical binding of the saccharides to the nanoparticle surface, a process that can be monitored through observation of the peak frequency of the particle plasmon resonance as manifest in the visible extinction spectrum. These saccharide-presenting substrates can then be exposed to other components of relevance to extracellular polymeric substance (EPS) driven aggregation processes, such as calcium, magnesium, metal oxide nanoparticles, and other oligo- or polysaccharides, under various controlled conditions. Again, the sensor nanoparticle plasmon resonance can be used to monitor assembly of these secondary components. It is anticipated that the binding data provided by these experiments will prove useful in identification of the important interactions in EPS-driven colloidal aggregation.
RP177 (MCD-1117-826733) A Novel Method for Observing and Quantifying Surface Wetting Characteristics Employing AutoCAD.
Start time: 8:00 AM
McDaniel, Les1, Romero, Nicholas1, Coimbatore, Gopal1, Cobb, George1, 1 The Institute of Environmental and Human Health, Texas Tech University, Lubbock, Texas, USA
Our group has developed an inexpensive and novel method for measuring contact angles of liquids on solid surfaces using a computer microscope and AutoCAD© 2005 drafting software. This method was developed to fulfill the needs of our chemical sensors development program for confirming the presence of self assembled monolayers (SAMs) and liquid crystals (LCs) after deposition onto solid surfaces. Photographs (.jpeg) of 1l droplets of known liquids resting on the surfaces of interest are taken with a Digital Blue™ QX5™ Computer Microscope and are copied and then pasted into the AutoCAD© design window. Droplet images are then manipulated with two dimensional line drawings to determine the angle of contact in order to make inferences about the characteristics of the solid surfaces. Using AutoCAD©, images of droplets on surfaces were overlain with simple geometric shapes matching all profiles. Once these reference lines were applied, s were determined via the AutoCAD© software. Multiple surfaces were tested using this method including N-type silicon wafers, 10-20nm thickness gold layer on N-type silicon wafers, a carboxyl-terminated SAM, and an LC layer. For these analyses, three test liquids of varying polarities were enlisted: Milli-Q water, diiodomethane, and ethylene glycol droplets were applied to all surfaces independently. Two replicates of surface groups were tested independently and retested separately to determine repeatability of the procedure. Angles determined as thus were predictable and consistent with literature values. We concluded that expensive software and optical apparatus are not required to perform consistent analyses of surface wetting characteristics. This method of determining the surface energies of solid surfaces has proven reliable in confirming our predictions based on the chemical and physical properties of those surfaces.
RP178 (BAY-1117-788444) Permeation liquid membrane as a sensor for free nickel ion in natural waters.
Start time: 8:00 AM
BAYEN, S.1, WORMS, I.1, WILKINSON, K.1, BUFFLE, J.1, 1 Department of Inorganic, Analytical and Applied Chemistry (CABE), Geneva, Switzerland
The permeation liquid membrane (PLM) technique is a useful tool to study trace element speciation. An organic phase, containing a carrier molecule, supported on a polymer membrane, separates the test solution from a receiving solution. Under carefully controlled conditions, the flux through the membrane can be closely related to the concentration of the free ion or to the free ion and some of the labile metal complexes. Various PLM cells, using flat sheet or hollow fiber permeation membranes, are currently available. This work reports the use of the PLM for the determination of nickel speciation in aqueous samples. Several parameters, such as the type of membrane and the composition of the organic phase were studied to obtain optimum fluxes over a wide Ni2+ concentration range (1 nM to 100 M). The PLM devices were characterized by measuring Ni fluxes in the absence or presence of complexing agents. Comparison with theoretical calculations and other techniques such as a resin based speciation setup were included in order to validate the Ni flux measurements and to relate them to the free Ni2+ ion concentration in the sample. The effect of potentially co-transported ions, sodium or calcium, on Ni transport through the PLM was also determined. In order to assess the usefulness of the technique as a Ni2+ sensor to evaluate bioavailability in natural waters, Ni PLM measurements (fluxes) were compared to the Ni internalization fluxes by freshwater algae under identical experimental conditions as above.
RP179 (BEL-1117-213533) LuminoTox: a rapid, portable and effective tool for toxicity screening in water.
Start time: 8:00 AM
Bellemare, F.1, Rouette, M. E.1, Lorrain, L.1, Perron, E.1, Boucher, N.1, 1 Lab_Bell, Shawinigan, Quebec, Canada
Lab-Bell has developed the LuminoTox, a screening biosensor enabling the rapid determination of effluent and/or water toxicity. This test is based on the inhibition of chlorophyll fluorescence by photosynthetic systems. The combined use of photosynthetic enzyme complexes (PECs), isolated from higher plants, and whole photosynthetic organisms (algae) allows a wider range of toxic inhibitors to be detected in just 10 to 15 minutes since photosynthetic light reactions are sensitive to a variety of pollutants including metal ions, PAH, herbicides, cyanide etc. The detection thresholds for specific molecules obtained with PECs and algae are presented. The results indicate that algae are less sensitive to metal ions than PECs, due to the algal cell walls being ion selective (in 10 minutes of incubation time). However, other toxic molecules, such as phenolic compounds and nitrogen ammonia, are much more detected in 10 minutes by algae. Nitrogen ammonia's threshold, as well as primary, secondary and tertiary amines, is pH-dependent, with optimal sensitivity being obtained at pH 11. The combination of PECs and algae is not only useful for rapid toxicity screening but also to obtain results as sensitive as standards bioassays. The results obtained for mining industry effluents demonstrate that PECs routinly prove as sensitive as daphnia, while algal sensitivity is comparable to that of the standard trout bioassay, even when toxicity is dependent on trophic levels. Importantly however, this toxicity sensitivity is obtained in just 10 and 15 minutes respectively for algae and PECs, versus 48 and 96 hours for daphnia and trout.
RP180 (ARI-1117-782974) The Simplified Analyzing Technologies for Monitoring verified by Environmental Technology Verification of Japan.
Start time: 8:00 AM
Arizono, K1, Yoshida, Y, Kamiya, K2, 1 Pref. Univ. Kumamoto, Kumamoto, Kumamoto, Japan2 Environmental Health and Safety Division, MOE, Tokyo, Tokyo, Japan
Advanced environmental technologies, even though they are commercial-ready and seem to be useful, have not necessarily been pervasive widely since the users such as local governments, companies and citizens, cannot obtain those technologies because of the lack in objective assessments, concerning the performance in environmental conservation. Ministry of the Environment (MOE) of Japan, therefore, launched the Pilot Project of the Environmental Technology Verification (ETV) in 2003 as a trial implementation of ETV, to verify objectively the performance of the advanced environmental technologies by third parties. As one of the technology fields to be verified in 2004 & 2005, the simplified analyzing technologies for monitoring was specified for this Pilot Project are those that analyze the chemicals in the environment more simply than the official method. The technologies are to be applied with antigen and antibody reaction, for instance, enzyme immunoassay, fluorescence immunoassay, and so on, and to target the chemicals of PRTR system and endocrine disrupting substances (or suspected endocrine disrupting substances). PRTR is a method for accurately assessing, aggregating, and disseminating data on the sources from where diverse hazardous chemicals are released, amounts released to the environment, and amounts transferred off-site from industrial establishments via waste products. Detailed information will be presented.
RP181 (ROM-1117-831934) Design, construction, and operation of a field portable vapor generation and calibration unit.
Start time: 8:00 AM
Romero, N1, McDaniel, L1, Coimbatore, G1, Cobb, G1, 1 The Institute of Environmental and Human Health, Texas Tech University, Lubbock, Texas, USA
A vapor generation system has been designed and is being tested in efforts to produce low, precisely known concentrations of organophosphorous surrogates of chemical warfare agents. This system was constructed to be field portable for testing and calibration of near real time sensors. With the production of a consistent vapor stream of known concentration, this system is also a practical means for steady vapor exposure during the development of sensors. With relatively uncomplicated operation this novel design permits easier handling of toxicants with less risk of exposure within the vapor chamber. Through the manipulation of heat and carrier gas (UHP N2), the desired concentration can be achieved. With the production of vapors from, 173.51 ± 77.26 to 138.16 ± 10.92 g/L; through manipulation of carrier gas flow lower concentrations can be evolved. An in-house design feedback temperature controller system was integrated into the system to maintain a precise isothermal temperature within a compartment containing the desired analyte. Flow meters were also incorporated to more accurately manage the carrier gas directed to the chamber containing the compound. Vapors evolving from this system were verified and quantified using a GC/MSD. The vapor generation system is currently being tested with various vapor pressure and molecular weight organophosphorous analytes. This design is specifically suited to be field portable and to be operational under most conditions. Sensors are being designed and constructed concurrently, will use this system to aid in there development.
RP182 (STE-1118-089359) Evaluation of fungal acute toxicity of metals to basidiomycete fungi using a Brazilian bioluminescent species Gerronema viridilucens.
Start time: 8:00 AM
Mendes, L1, Prada, S2, Stevani, C1, 1 Universidade de São Paulo, São Paulo, SP, Brazil2 Centro Universitário FIEO, Osasco, SP, Brazil
In a previous study, we developed a fungal-based bioluminescent assay in agar medium in order to evaluate the toxicity of metal and organic toxicants to basidiomycete fungi. This assay was based on the acute toxicity response (EC50 values) against toxicants sprayed on the surface of G. viridilucens mycelium. The damage was measured by decreasing the bioluminescence intensity according to toxicant-concentration level. Preliminary EC50 values obtained for Cu(II) (ca. 100 uM) and pentachlorophenol (ca. 2 uM), with an average standard deviation of twenty percent, indicated that the assay is reliable and suitable for both organic and inorganic samples. In order to obtain more information regarding the viability of this procedure to assess the toxicity of metals in environmental samples as well as to build a broader library of metal EC50 values, a new study was carried out using essential (Ni(II), Mn(II), Na(I), K(I), Mg(II), Ca(II)) and non-essential (Pb(II), Cd(II), Al(III)) metal series. The results confirmed the expected high toxicity of these non-essential metals to fungi and indicated that the assay could be also applied to more complex metal-contaminated environmental samples, which will be investigated soon.
RP183 (GAL-1117-825124) The Use of Passive Metal Sampling Devices to Estimate Accumulation of Metals in Marine Bivalves.
Start time: 8:00 AM
Galvin, J1, Shine, J1, 1 Harvard School of Public Health, Boston, MA, USA
Bivalves are commonly used as tools to assess the presence of contaminants in coastal marine ecosystems, and have been incorporated into large, formal monitoring programs such as the Mussel Watch of the National Status and Trends program. A new metal speciation tool, the Gellyfish, has been shown to calibrate with free metal ions in solution. Because metal bioavailability to aquatic organisms is a function of metal speciation and free metal ion activity, an extension of this research was to assess whether the Gellyfish can also be used to estimate biological uptake of metals by marine organisms. Several field deployment campaigns have been conducted to evaluate the utility of these samplers as biomimics of bivalve metal exposure. Studies were conducted over a two-year period in Boston Harbor, Massachusetts Bay, and Cape Cod Bay by deploying Gellyfish alongside mussels (Mytilus edulis). Bivalve tissue and Gellyfish were analyzed for a suite of metals (e.g., Cu, Zn, Ag, Cd, Pb, Co, Cr, Ni). Four factors (metal assessed, exposure time, deployment site, study year) were considered when evaluating monitor performance. Regressions between the two measurements were significant for a number of metals, with r2 values as high as 0.92 for Pb. The statistical relationship between Gellyfish and mussel tissue is subsequently used to determine an optimal monitoring strategy with respect to the number of Gellyfish or mussel samples to be deployed in space or time. The Gellyfish are thus promising new devices that can enhance the power of a monitoring program in assessing spatial or temporal trends. A potential weakness with the use of biomonitoring organisms is reliance on the use of live organisms, where mortality or other metabolic processes may hinder the quality or quantity of data collected. These issues do not apply to the Gellyfish, and their low cost and simplicity will afford faster and easier metal assessment than the deployment biomonitoring organisms.
RP184 (HUL-1117-860897) Nanomechanical cantilever arrays for environmental monitoring applications.
Start time: 8:00 AM
Hull, M1, 1 Luna Innovations Inc., Blacksburg, VA, USA
Fiber-optic nanomechanical cantilever arrays (NCA) have been developed for widespread application in environmental monitoring applications. NCAs orginate from atomic force microscopy (AFM) and have emerged as an exciting new sensor technology combining microelectromechanical systems (MEMS) with nanomechanics and biochemical surface functionalization. As target molecules are adsorbed or desorbed at the functionalized surfaces of AFM cantilevers, physical and chemical changes deflect the cantilever in a concentration-dependent fashion. The resulting deflection of the cantilever is then measured with sub-nanometer sensitivity in both gaseous and fluid media using fiber-optic interferometry. In theory, a single sensing device could consist of thousands of micron-sized cantilever arrays, each functionalized with a different adsorbent film or polymer coating to provide selective detection of dozens of chemical and biological targets in complex mixtures of gases and fluids. NCA sensors will be adaptable for numerous applications in environmental monitoring, homeland defense, smart-building HVAC systems, food safety, process monitoring, and medical diagnostics.
RP185 (PUT-1117-831200) Real-time In Situ Measurement of Total Recoverable Copper.
Start time: 8:00 AM
Putnam, Mike1, Rivera, Ignacio1, Arias, Ernie1, 1 Space and Naval Warfare Systems Center, San Diego, San Diego, CA, USA
Regulatory measures require the monitoring of total recoverable and/or dissolved metal concentrations in effluents. US EPA's National Pollutant Discharge Elimination System permits often require monitoring of the total recoverable concentration, while the EPA's Water Quality Criteria require monitoring of dissolved concentrations of copper in the effluent. Total recoverable copper concentrations are typically measured after acidification and digestion of the effluent, while dissolved copper concentrations are measured after acidification and digestion of effluent that was previously filtered through a 0.45 micron pore size filter. A new instrument has been developed that can measure the total recoverable concentration, or dissolved concentration, of copper in point and non-point source discharges in the field. Field and laboratory data from this instrument will be compared with EPA Method 3020A "Acid Digestion of Aqueous Samples and Extracts for Total Metals for Analysis by GFAA Spectroscopy."