Grantee Research Project Results

Conducting-Polymer Nanowire Immunosensor Arrays for Microbial Pathogens

EPA Grant Number: GR832375
Title: Conducting-Polymer Nanowire Immunosensor Arrays for Microbial Pathogens
Investigators: Mulchandani, Ashok , Yates, Marylynn V. , Myung, Nosang V. , Chen, Wilfred
Current Investigators: Mulchandani, Ashok , Chen, Wilfred , Yates, Marylynn V. , Myung, Nosang V.
Institution: University of California - Riverside
EPA Project Officer: Hahn, Intaek
Project Period: June 1, 2005 through March 31, 2008 (Extended to March 31, 2009)
Project Amount: $320,000
RFA: Greater Research Opportunities: Research in Nanoscale Science Engineering and Technology (2004) RFA Text |  Recipients Lists
Research Category: Nanotechnology , Safer Chemicals

Objective:

A promising approach for the direct (label-free) electrical detection of biological macromolecules uses one-dimensional (1-D) nanostructures such as nanowires and nanotubes, configured as field-effect transistors that change conductance upon binding of charged macromolecules to receptors linked to the device surfaces. Combined with simple, rapid and label-free detection, potentially to single molecule, these nanosensors are also attractive due to the small size, low power requirement and most of all possibility of developing high density arrays for simultaneous analyses of multiple species. Although current nanosensor based on carbon nanotubes and silicon nanowires has elucidated the power of 1-D nanostructures as biosensors, they have low throughput and limited controllability and are unattractive for fabrication of high-density sensor arrays. More importantly, surface modifications, typically required to incorporate specific antibodies, have to be performed post-synthesis and post-assembly, limiting our ability to individually address each nanostructured sensing elements with the desired specificity.

The overall objective of the proposed research is to develop a novel technique for the facile fabrication of bioreceptor (antibody) -functionalized nanowires that are individually addressable and scalable to high-density biosensor arrays and to demonstrate its application for label-free, real-time, rapid, sensitive and cost-effective detection of multiple pathogens in water. Electropolymerization of conducting polymers between two contact electrodes is a versatile method for fabricating nanowire biosensor arrays with the required controllability. The benign conditions of electropolymerization enable the sequential deposition of conducting-polymer nanowires with embedded antibodies onto a patterned electrode platform, providing a revolutionary route to create a “truly” high-density and individually addressable nanowire biosensor arrays. The nanowire immunosensor arrays utility will be used to simultaneously quantify three important model pathogens, poliovirus, hepatitis A virus and rotarvirus.

Approach:

We will use our recently reported (Ramanathan et al., 2004) simple yet powerful facile technique of electrochemical polymerization of biomolecule-friendly conducting polymers such as polypyrrole, in prefabricated channels of tailor-made aspect ratio between two contact electrodes at site-specific position to synthesize nanowires of tailor-made properties for fabricating individually addressable high density nanowires biosensors arrays. Detection of pathogens will be achieved by the extremely sensitive modulation of the electrical conductance of the nanowires brought about by the change in the electrostatic charges from binding of the pathogens to the antibodies.

Effects of monomer concentration, dopant type and concentration, aspect ratio and electrochemical polymerization mode on the sensitivity, selectivity and durability of poliovirus, HAV and rotavirus antibodies-functionalized polypyrrole nanowires as label-free bioaffinity sensor of these important model virual pathogens in water will be investigated to establish optimum synthesis conditions of biomolecules-functionalized nanowires to successfully realize our innovation to practice.

Expected Results:

The lack of methods for routine rapid and sensitive detection and quantification of specific pathogens has limited the amount of information available on their occurrence in drinking water and other environmental samples. The nanowire biosensor arrays developed in this study would improve the ability to provide rapid and ultrasensitive quantification of pathogens. The end results of this research will be a nanoelectronic sensor for rapid, sensitive, selective and reliable detection of multiple important viruses simultaneously that will be useful not only for water and environmental monitoring but also homeland security, health care, and food safety. Additionally, the technique of hierarchical assembly of high density nanowire arrays developed in this research will also find application in the rapidly advancing fields of proteomics and genomics.

Publications and Presentations:

Publications have been submitted on this project: View all 9 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 7 journal articles for this project

Supplemental Keywords:

nanosensors; viruses; bacteria; monitoring; water., Sustainable Industry/Business, RFA, Ecosystem Protection/Environmental Exposure & Risk, Scientific Discipline, Water, POLLUTANTS/TOXICS, Chemical Engineering, Environmental Chemistry, Engineering, Chemistry, & Physics, Monitoring/Modeling, New/Innovative technologies, Environmental Engineering, Environmental Monitoring, Water Pollutants, electrochemical polymerization, homeland security, environmental measurement, carbon nanotubes, nanowires, nanoengineering, nanotechnology, nanosensors, analytical chemistry, continous monitoring, microbial pathogens, continuous monitoring, nanocontact sensor, immunosensor arrays, bioterrorism

Progress and Final Reports:

2005 Progress Report

2006 Progress Report

2007 Progress Report

Final Report