Development and Characterization of Antibody Molecules on Peg Tethered Aln-Based Biosensors
Ting Cao1, Anfeng Wang1, Xuemei Liang1, Haiying Tang1, Gregory W. Auner2, Steven O. Salley1, and K. Y. Simon Ng1. (1) Department of Chemical Engineering and Materials Science, Wayne State University, 5050 Anthony Wayne Dr., Detroit, MI 48202, (2) Department of Electrical and Computer Engineering, Wayne State University, 5050 Anthony Wayne Dr., Detroit, MI 48202
Of primary concern in the design of biosensors is the immobilization of biomolecules such as proteins or antibodies to the biosensor surface, which determines the primary properties of the biosensor. The using of spacers, which can increase the flexibility of immobilized molecules, is one promising protocol to improve the bioactivity or capture efficiency of immobilized antibodies. In this research, two issues were addressed. First, PEG (polyethylene glycol) was investigated as a spacer, which may allowed the antibody to freely reorient and potentially improving the antigen capture efficiency. PEG length and density were the key parameters to be optimized in studying its effect on the immobilization of antibody. E.coli K99 pilus antibody was immobilized on AlN using different tethers. The quality of each functionalization procedure was characterized by X-ray photoelectron spectroscopy (XPS) and Atomic Force Microscopy (AFM). Second, the specifity and capture efficiency of the antibody-immobilized surfaces were then evaluated by Acoustic Wave Sensors using different types of E.Coli strains. Scanning Electronic Microscopy (SEM) was also preformed to investigate the capture efficiency of antibody. Quantitative results from Acoustic Wave Sensor and SEM indicated that PEG tethered surfaces showed an improved bioactivity and high capture efficiency. This work provides a novel approach for tailoring a high sensitive biorecognition system on AlN substrates.