Development of an Antibody Functionalized Carbon Nanotube Biosensor for Foodborne Bacterial Pathogens
- *Corresponding Author:
- Shreekumar Pillai
Department of Math and Science
and Center for NanoBiotechnology and Life Sciences Research
Jackson Street, Alabama State University
Montgomery, Auburn, USA
E-mail: [email protected]
Received Date: June 21, 2012; Accepted Date: July 19 10, 2012; Published Date: July 23, 2012
Citation: Jain S, Singh SR, Horn DW, Davis VA, Pillai S, et al. (2012) Development of an Antibody Functionalized Carbon Nanotube Biosensor for Foodborne Bacterial Pathogens. J Biosens Bioelectron S11:002. doi: 10.4172/2155-6210.S11-002
Copyright: © 2012 Jain S, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
With increasing reports on bioterrorism and other bio-threats, rapid and real time detection methods for various pathogens are warranted. Attempts have been made to improve electrochemical biosensor performance by incorporating Carbon Nanotubes (CNTs). The high surface area of CNTs allows both immobilization of antibodies and electrochemical measurements. Salmonella monoclonal antibodies were covalently attached onto CNTs by using diimide activated imidation coupling. CNTs functionalized with antibodies were immobilized onto a glassy carbon electrode and the presence of pathogen was detected by studying the changes in charge transfer resistance and impedance, before and after the formation of antigen-antibody complex. CNTs behave as molecular wires allowing electrical communication between the underlying electrode and the conjugated antigen-antibody complex. Nyquist plots and cyclic voltammograms were studied and comparisons have been made between glassy carbon electrodes as working-electrode by itself, electrodes immobilized with antibodies and after the formation of antigen-antibody complex. Cyclic voltammeter experiments had a potential scan rate of 100 mVs-1, step height of 1.0 mV and applied potential from -1.0 V to 1.0 V. The electrochemical impedance experiments applied a frequency range of 100 kHz -100 mHz with an AC sine wave amplitude of 10 mV. Amplification in the current density was observed for CNTs immobilized on the electrode surface and decrease in current density and increased impedance was observed after the antigens bound specific antibodies. Enzyme-Linked Immune Sorbent Assay (ELISA) was done to determine the titer of the antibodies and their sensitivity at different dilutions for antigen detection. This technique could be an effective way to sense the formation of antigen-antibody complexes, with the potential to make the detection process rapid as compared to conventional pathogen detection methods.