Reaching (sub-)micrometer resolution of photo-immobilized proteins using diffracted light beams

We have developed a photonic technology that allows for precise immobilisation of proteins to sensor surfaces. The technology secures spatially controlled molecular immobilisation since the coupling of each molecule to a support surface can be limited to the focal point of the UV laser beam, with dimensions as small as a few micrometers. The ultimate size of the immobilized spots is dependent on the focal area of the UV beam. The technology involves light induced formation of free, reactive thiol groups in molecules containing aromatic residues nearby disulphide bridges. It is not only limited to immobilizing molecules according to conventional patterns like microarrays, as any bitmap motif can virtually be used a template for patterning. We now show that molecules (proteins) can be immobilized on a surface with any arbitrary pattern according to diffraction patterns of light. The pattern of photo-immobilized proteins reproduces the diffraction pattern of light expected with the optical setup. Immobilising biomolecules according to diffraction patterns of light will allow achievement of smaller patterns with higher resolution. The flexibility of this new technology leads to any patterns of photo-imprinted molecules, with micrometer resolution, thus being of relevance for present and future applications in nanotechnologies.