![[logo] US EPA](http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
2004 Progress Report: Advanced Nanosensors for Continuous Monitoring of Heavy Metals
EPA Grant Number: R830906Title: Advanced Nanosensors for Continuous Monitoring of Heavy Metals
Investigators: Sadik, Omowunmi , Mulchandani, Ashok , Wang, Joseph
Institution: SUNY at Binghamton , New Mexico State University , University of California - Riverside
EPA Project Officer: Savage, Nora
Project Period: May 19, 2003 through April 18, 2006
Project Period Covered by this Report: May 19, 2004 through April 18, 2005
Project Amount: $351,000
RFA: Environmental Futures Research in Nanoscale Science Engineering and Technology (2002)
Research Category: Nanotechnology
Description:
Objective:The overall objective of this work is to incorporate novel, colloidal-metal nanoparticles into a bed of electrically conducting polymers and use these to develop nanosensors. We also seek to explore the feasibility of designing advanced conducting polymeric materials for remediation applications.
Progress Summary:During Year 1 of the project, we reported new synthetic approaches for polyamic acid-silver nanoparticle composite membranes, polyoxydianiline films and electrochemical deposition of gold nanoparticle films onto functionalized conducting polymer substrates. We used the unique reactivity of polyamic acid (PAA) to design polymer-assisted nanostructured materials by preventing the cyclization of the reactive soluble intermediate into polyimides at low temperatures. The ability to prevent the cyclization process enabled the design of a new class of electrode materials using thermal reduction and/or electrodeposition. During this reporting period, we selected one of the synthetic nanostructured materials reported in Year 1, and tested this as an environmental catalyst for the conversion of higher valent to low valent Cr in soil and water samples.
The application of the Pd nanoparticles-sulfur mixture was tested using actual soil samples, resulting in more than 92 percent conversion in the presence of Pd-NPs/S within 1 hour. In contrast, only 33 percent of the same concentration was converted to Cr (III) in the absence of Pd-NPs/S. This represents a greater than 500-fold improvement in conversion rate compared to current microbial approaches. This work offers a new application of nanotechnology for the reduction of high oxidation state heavy metal pollutants. In addition, the bismuth electrode-cupferon complex has been tested for the detection of uranium using anodic stripping voltammetry. A detection limit of 0.3 μg/L is observed in connection to a 10 min adsorption time. The response is linear up to 50 μg/L and the relative standard deviation at 50 μg/L uranium is 3.8%(n=15, 2 minute adsorption). This detection limit meets the requirements of monitoring contaminated sites and most water quality applications.
Applicability to seawater samples is has also been demonstrated and the resulting behavior of the new “mercury-free” uranium sensor holds great promise for on-site environmental and industrial monitoring of uranium It implies that the response observed for real sample is lower than that recorded for synthetic samples, thus the method is analytically useful.
Future Activities:Our next goal is to optimize our approach for the environmental remediation of Cr (VI) by building a reactor. The reactor design will be completed and tested for the conversion of Cr (Vi) to Cr (III) in different soil environments. Parameters to be optimized include types of soil, porosity, and amount of Pd-NPs, time, temperature and pH. In addition, we will conduct a simultaneous characterization and optimization of the polymers for metal detection and speciation at the State University of New York and Arizona State University.
Journal Articles on this Report: 4 Displayed | Download in RIS Format
| Other project views: | All 37 publications | 14 publications in selected types | All 11 journal articles |
| Type | Citation | ||
|---|---|---|---|
|
|
Andreescu D, Wanekaya A, Sadik OA, Wang J. Nanostructured polyamic acid membranes as novel electrode materials. Langmuir 2005;21(15):6891-6899. |
R830906 (2003) R830906 (2004) R830906 (Final) |
not available |
|
|
Andreescu D, Sadik OA. Synthesis of polyoxydianiline membranes onto gold electrodes. Journal of the Electrochemical Society 2005;152(10):E299-E307. |
R830906 (2004) R830906 (Final) |
not available |
|
|
Andreescu S, Sadik OA. Correlation of analyte structures with biosensor responses using the detection of phenolic estrogens as a model. Analytical Chemistry 2004;76(3):552-560. |
R830906 (2004) R830906 (Final) |
not available |
|
|
Lin L, Thongngamdee S, Wang J, Lin Y, Sadik OA, Ly S-Y. Adsorptive stripping voltammetric measurements of trace uranium at the bismuth film electrode. Analytica Chimica Acta 2005;535(1-2):9-13. |
R830906 (2004) R830906 (Final) |
not available |
nanomaterials, nanotechnology, environmental application, metal analysis, remediation, innovative technology, heavy metals, environmental chemistry, nanoscale sensors,
,
Ecosystem Protection/Environmental Exposure & Risk, POLLUTANTS/TOXICS, Water, INTERNATIONAL COOPERATION, Sustainable Industry/Business, Scientific Discipline, RFA, Arsenic, Engineering, Chemistry, & Physics, Drinking Water, Chemicals, Environmental Engineering, Water Pollutants, Environmental Chemistry, New/Innovative technologies, Monitoring/Modeling, Environmental Monitoring, drinking water contaminants, heavy metals, water quality, nanotechnology, nanosensors, organic gas sensor, health effects, nanocontact sensor, analytical methods, nanocrystals, micro electromechanical system, monitoring, carbon nanotubes, nanoengineering, monitoring sensor, colloidal metal nanoparticles, continous monitoring, environmental measurement
Relevant Websites:
http://chemistry.binghamton.edu/SADIK/sadik.htm 
Progress and Final Reports:
2003 Progress Report
Original Abstract
Final Report