Ultra-sensitive Electrochemical Detection of E. coli Using Nano-porous Alumina Membrane

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A combinational method has been developed for ultra-sensitive detection of E. coli. The method combined biological, nano-fabrication and electrochemical techniques to achieve highly specific and ultra-sensitive detection of bacterial pathogen. E. coli K12 was used as the target bio-agent to demonstrate the detection model. Nano-porous alumina membrane was chosen as filtration substrate to separate E. coli from the test samples because of their desirable physical properties. The surface of the membrane was modified in a unique way and not to bind to biological molecules. Bacterophage M13 was genetically modified with histag on its minor coat protein III. This phage was used to infect its specific bacterial host and replicated in side of the host. The nano-porous alumina membrane was used to filtrate exceeded phages and separated infected E. coli from the test sample. The generation time of phage replication was investigated. After a short period of culture, the amplified bacterophage, 102 -103/E. coli, was released from the host. These baterophage were detected selectively and specifically by on an electrochemical device. Various surface modification approaches were used to test the efficiency of target capture and detection sensitivity on detection electrode. The immobilized antibody on gold electrode has shown greater stability and specificity compare to others.

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Journal: TechConnect Briefs
Volume: 3, Nanotechnology 2008: Microsystems, Photonics, Sensors, Fluidics, Modeling, and Simulation – Technical Proceedings of the 2008 NSTI Nanotechnology Conference and Trade Show, Volume 3
Published: June 1, 2008
Pages: 343 - 346
Industry sectors: Medical & Biotech | Sensors, MEMS, Electronics
Topic: Micro & Bio Fluidics, Lab-on-Chip
ISBN: 978-1-4200-8505-1