AVS 50th International Symposium
    Biomaterial Interfaces Wednesday Sessions
       Session BI-WeP

Paper BI-WeP7
Molecular Engineering of Surfaces for Sensing and Detection

Wednesday, November 5, 2003, 11:00 am, Room Hall A-C

Session: Poster Session
Presenter: Q. Yu, University of Washington
Authors: C.L. Boozer, University of Washington
J. Ladd, University of Washington
A. Taylor, University of Washington
Q. Yu, University of Washington
J. Homola, University of Washington
S. Jiang, University of Washington
Correspondent: Click to Email
There is an urgent demand for developing sensors capable of quantitative and simultaneous detection, identification, and monitoring of multiple analytes in complex media for various applications ranging from homeland security and medical diagnostics to food and environmental monitoring. Immunological detection with antibodies is perhaps the only technology that has been successfully employed for the detection of bacteria, viruses, proteins, and low-molecular-weight compounds. In this talk, we will discuss our recent effort on molecular engineering of surfaces for sensing and detection. First of all, control of antibody orientation is achieved on charged surface assembled monolayers (SAMs). Antigen is used to probe antibody orientation measured by surface plasmon resonance (SPR) biosensor while direct evidence of preferred antibody orientation is provided by the time-of-flight secondary ion mass spectrometry. Second, it was shown in our previous work that the behavior of protein adsorption depended on nano-scale structures of a surface with which proteins interact. Polyethylene glycol (PEG) SAMs are used as a model surface to study surface resistance to protein adsorption. Atomic force microscopy/scanning tunneling microscopy (AFM/STM), SPR and molecular dynamics simulation techniques are used in such studies. Results show light on molecular-level understanding of non-fouling mechanism. Third, a new DNA-based protein immobilization method has been developed for use with SPR biosensors. This DNA-based immobilization method provides a convenient and versatile for multi-channel biosensors. We will demonstrate the quantitative and simultaneous detection of various analytes ranging from larger-sized to small-molecular weight analytes (e.g., E. coli, SEB, and simazine) in complex matrices (e.g., milk and ground beef) based on this new platform. Finally, we achieved single-molecular detection of immunoreactions using an AFM-based sensor.