Nanotek & Expo

Biography

Biography: William E Lee

Abstract

Nanotechnology has tremendous potential to enhance the performance of biosensors. The chemical, electronic, and optical properties of nanomaterials generally depend on both their dimensions and their morphology. A major advantage of using nanomaterials in biosensing is the number of bioreceptor molecules immobilized on the detector surface can be as low as a single molecule. As a result the number of analyte molecules required to generate a measurable signal could be just a few, providing very low limits of detection. As a sensitive, non-destructive, and label-free detection method, electrochemical impedance spectroscopy (EIS) has recently received considerable attention for the characterization of electrical properties in biological interfaces. We self-assembled gold nanoparticles on gold electrodes to yield multi-layered molecular structures for sensitive pathogen detection and in situ regeneration of the sensor electrode. The use of molecular self-assembly and gold nanoparticles plus EIS detection rendered a detection limit of 30 virus particles/ml for adenovirus 5 and 100 cells/ml for E-coli 0157:H7. The gold nanoparticle sensor surface could be self-assembled and regenerated on the electrode at least 30 times without losing analytical performance. We also fabricated metal oxide nanoporous-film electrodes, using glancing angle deposition (GLAD) technique, for highly sensitive detection of pathogens. GLAD utilizes oblique angle physical vapor deposition combined with precise substrate rotation to engineer nano-columns. The combination of nanotechnology and EIS is an attractive and powerful concept for future chemical and biological sensors research and integration in to lab-on-a-chip devices for field deployable sensors.