Diffraction Limited Light Assisted Protein Immobilization
S.B. Petersen, T.N. Petersen, E. Skovsen
Aalborg University, DK
biosensor, immobilization, diffraction limited, light assisted protein immobilization
Photonic induced immobilisation of biosensor molecules is a novel patented technology that results in spatially tethered and spatially localised covalent coupling of protein molecules onto thiol reactive surfaces, e.g. thiolated glass/quartz, gold or silicon. The reaction mechanism behind the reported new technology involves light-induced breakage of disulphide bridges in proteins upon UV illumination of nearby aromatic amino acids resulting in the formation of reactive molecules that may react to form covalent bonds with thiol reactive surfaces. The spatial resolution achievable with direct illumination using a focussed laser beam is limited to the size of the focal spot. We have reported that 5-10 micron spots size is routinely achieveable. The protein molecules remain biochemically active. Fab fragments comply with this methodlogy and binds their antigen. We have now improved the resolution limit dramatically using fourier optics. We are now able to reach sub-micron spot size with our light assisted protein immobilization. After image processing we achieve spot sizes down to 500 nm. This implies that 1 million individual sensor spots can be located inside a 1 mm2 surface patch. We are convinced that this technology will become a cornerstone of the next generation ultra dense biosensor development. The search and identification of biomarkers for human disease is another attractive application of our technology.
Nanotech 2008 Conference Program Abstract