Detection of tumor markers based on extinction spectra of visible light passing through gold nanoholes

The authors demonstrate that nanometric holes in optically thin gold films on glass slides can be used as biochemical sensors based on extinction spectra of visible light passing through these holes. Binding and adsorption of biomolecules to the surfaces of gold and glass result in a redshift of the localized surface plasmon resonance peak in the extinction spectrum of the gold holes. Selective sensing of antigens such as cancer antigen 19-9 (of less than 1 pg on an similar to 0.1 mm(2) probing area) can be realized using this type of devices after functionalizing the gold and glass surfaces with bioreceptors. (c) 2007 American Institute of Physics.