Grantee Research Project Results
1999 Progress Report: Development of a New Microelectrode Array Biosensing System for Environmental Monitoring
EPA Grant Number: R825323Title: Development of a New Microelectrode Array Biosensing System for Environmental Monitoring
Investigators: Sadik, Omowunmi
Institution: The State University of New York at Binghamton
EPA Project Officer: Hahn, Intaek
Project Period: October 1, 1996 through September 30, 1999 (Extended to September 30, 2000)
Project Period Covered by this Report: October 1, 1998 through September 30, 1999
Project Amount: $280,095
RFA: Analytical and Monitoring Methods (1996) RFA Text | Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , Environmental Statistics , Water , Air , Land and Waste Management
Objective:
The objectives of the research project are to: (1) develop multiarray sensors for monitoring environmental contaminants using conducting polymers, and (2) utilize these sensors for field trial using selected analytes.Progress Summary:
Major efforts of this research program include the development of biosensors suitable for continuous monitoring and control of environmental pollutants such as polychlorinated biphenyls (PCBs), metals, and volatile organic compounds (VOCs). Our overall goal is to understand the time and spatial concentration dependence of these pollution analytes in response to chemical and physical stimuli. Successfully ascertaining these behaviors may lead to the understanding of the fate and transport of these pesticides in the environment as well as provide a possible detoxification mechanism.Biosensors for Organochlorines. We have developed a unique, generic strategy for reversible immunosensors using conducting electroactive polymers based on pulsed electrochemical detection. This strategy has been adapted for the detection of some organochlorine pesticides, including PCBs, atrazines, and chlorinated phenols. We have introduced the concept of odor?structure relationships as an alternative approach to improving the performance of multiarray sensors used for the analysis of volatiles. Studies indicate that using gas chromatography-based electronic nose (GC-EN), we can now correlate sensor structures and activities to obtain better distinction of parameters that influence the properties of toxic compounds. We currently are developing a prototype instrument that will utilize this concept.
Sensors for Metal Ions. Recently, we reported the synthesis of new bioconjugates using a well-known chelator, 4-(2-pyridylazo) resorcinol (PAR). The conjugates were synthesized by linking PAR to proteins and enzymes. These conjugates were originally designed for the detection of environmental, toxic metal ions. The sensitivity of lead, mercury, and cadmium to PAR bioconjugates was very low. However, we found that these conjugates could be used for the detection of gallium in biological matrices under a nonantibody-based sandwich assay format. This technique resulted in a detection limit of 5 x 10-8 M. The selectivity for gallium (III) relative to nearly 30 other metal ions that were investigated was very remarkable. These preliminary findings clearly demonstrated the advantages of using a receptor-based binding assay to achieve highly sensitive and selective detection. Therefore, the successful replacement of antibodies by proteins that are conjugated to PAR ligands (as the recognition molecules) now represents a new approach for designing biosensors. Details of these findings have been published in peer-reviewed journals, including the Journal of Environmental Science & Technology (ES&T), Analytical Chemistry, Analytical Chimica Acta, and Journal of Electroanalysis.
? Three different pyrrole derivatives and polymer films now have been successfully synthesized and characterized as precursors for environmental biosensors.
? A new multi-analyte detection technique based on polypyrrole derivatives has been established for the qualitative detection of chlorinated phenols and other organics.
? The synthesis of new triazine-based haptens used for the development of biosensors for pesticides has been accomplished. These haptens were successfully used for the preparation of polyclonal antibodies. In addition, using these haptens was more efficient for detection of atrazine, cyanazine, and alachlor pesticides relative to existing techniques.
? A new identification and quantitation method for PCBs has been established using our newly synthesized pyrrole derivatives.
? The use of 2-pyridylazo protein conjugates for monitoring heavy metals has been explored. Consequently, we have reported a new sensing chemistry based on 2-puridylazo conjugates.
Future Activities:
Based on the accomplishments described above, we are very optimistic that this project is likely to end in the discovery of a powerful tool for in situ detection of environmental pollutants. However, work is still in progress. We plan to carry out further field demonstrations using the sensors and techniques already developed under this project. Projected plans during the next few months include:
? Stability studies of the sensor-arrays developed for PCBs and
polychlorinated phenols.
? Field demonstration of the multiarray sensors.
? Completion of manuscripts in preparation and issuance of final report to
EPA.
Journal Articles on this Report : 9 Displayed | Download in RIS Format
| Other project views: | All 70 publications | 9 publications in selected types | All 9 journal articles |
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Bender S, Sadik OA. Direct electrochemical immunosensor for polychlorinated biphenyls. Environmental Science & Technology 1998;32(6):788-797. |
R825323 (1997) R825323 (1998) R825323 (1999) R825324 (Final) |
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Masila M, Sargent A, Sadik OA. Pattern recognition studies of halogenated organic compounds using conducting polymer sensor arrays. Electroanalysis 1998;10(5):312-320. |
R825323 (1997) R825323 (1998) R825323 (1999) |
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Sadik OA. Bioaffinity sensors based on conducting polymers: A short review. Electroanalysis 1999;11(12):839-844. |
R825323 (1998) R825323 (1999) |
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Sadik OA, Bender S, Joasil P, Lord J. Electropolymerized conducting polymers as glucose sensors. Journal of Chemical Education 1999;76(7):967-969. |
R825323 (1998) R825323 (1999) |
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Sargent A, Sadik OA. Pulsed electrochemical technique for monitoring antibody-antigen reactions at interfaces. Analytica Chimica Acta 1998;376(1):125-131. |
R825323 (1997) R825323 (1998) R825323 (1999) |
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Sargent A, Sadik OA. Monitoring antibody-antigen reactions at conducting polymer-based immunosensors using impedance spectroscopy. Electrochimica Acta 1999;44(26):4667-4675. |
R825323 (1998) R825323 (1999) |
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Sargent A, Loi T, Gal S, Sadik, OA. The electrochemistry of antibody-modified conducting polymer electrodes. Journal of Electroanalytical Chemistry 1999;470(2):144-156. |
R825323 (1998) R825323 (1999) |
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Xu H, Lee E, Sadik OA, Bakhtiar R, Drader J, Hendrikson C. A receptor-based bioassay for quantitative detection of gallium. Analytical Chemistry 1999;71(23):5271-5278. |
R825323 (1998) R825323 (1999) |
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Yan F, Oszoz M, Sadik OA. Electrochemical and conformational studies of microcystin-LR. Analytica Chimica Acta 2000;409(1-2):247-255. |
R825323 (1998) R825323 (1999) |
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Supplemental Keywords:
environmental chemistry, analytical technologies, groundwater, soils, risk assessment, PCBs, PAHs, metals, biosensors, EPA Region 1, Region 2, Region 3, Region 4, Region 5, Region 6, Region 7, Region 8, Region 9, Region 10., RFA, Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Engineering, Chemistry, Electron Microscopy, Environmental Chemistry, Monitoring/Modeling, Physics, field portable monitoring, microelectrode, environmental monitoring, spectroscopic, environmental engineering, environmental measurement, groundwater, sensor technology, solid waste, biomonitoring, biosensing systemRelevant Websites:
http://chemiris.chem.binghamton.edu/SADIK/sadik.htm
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.