AVS 45th International Symposium
    Biomaterial Interfaces Group Monday Sessions
       Session BI-MoM

Paper BI-MoM10
Biosensing Using Colloidal Au Arrays as Biocompatible Substrates and Au:Protein Conjugates as Signal Enhancing Agents

Monday, November 2, 1998, 11:20 am, Room 326

Session: Protein Solid-Surface Interactions
Presenter: M.D. Musick, Pennsylvania State University
Authors: M.D. Musick, Pennsylvania State University
L.A. Lyon, Pennsylvania State University
G.P. Goodrich, Pennsylvania State University
M.J. Natan, Pennsylvania State University
Correspondent: Click to Email
Sensing strategies are discussed using arrays of colloidal Au as a sensor substrate and solutions of protein:Au colloid conjugates as signal amplification reagents. Colloidal Au shares similar properties with bulk Au, a common transducer substrate due to its reflectivity, conductivity, and ease of chemical modification. However, colloidal Au offers increased biocompatibility and flexibility. Particles can be assembled directly from solution onto a wide range of supports. Furthermore, particle size and spacing are easily controlled. 2-D and 3-D arrays have been fabricated from combinations of biomolecules, ligands, organic crosslinkers, and colloidal Au. Assemblies have been characterized by AFM, FE-SEM, uv-vis/NIR, electrical resistance, and electrochemical analysis. The stability and immobilization of protein:Au colloid complexes have been examined. An amplified surface plasmon resonance (SPR) sandwich assay is presented. In this assay, a protein layer immobilized on an evaporated Au film is exposed to analyte solution and incubated with a protein:Au conjugate. The result is a enhanced shift in the SPR curve as compared to conventional SPR. The use of colloidal Au amplified surface plasmon resonance should offer increased molecular weight sensitivity and lower detection limits. Imaging and arraying methods that allow for simultaneous analysis of many samples, and sensors based on changes in electrical and electrochemical signals will also be described.