Functional core-shell nanoparticles and applications in protein-bio-chip technology

In our approach to a flexible surface-chemistry for protein-immobilization we use core-shell nanoparticles as carriers for all different kinds of capture-molecules. Silica nanospheres are equipped with an organic shell using functional silanes and state-of-the-art bioconjugate chemistry to couple specific capture proteins such as antibodies, streptavidin etc. Affinity-nanoparticles applied in suspension have proven to be a very useful tool for protein-separation. We have shown that particle-bound proteins can be analysed by MALDI mass-spectrometry directly at the particlesx surface as nanoparticles do not desturb the MALDI-process. Furthermore we have demonstrated that functional nanoparticles can be deposited on activated surfaces in a micro-structured way by combination of a broad range of top-down structuring methods. Nanoparticles display a very large surface and thus layers of functional nanoparticles adsorbed to a solid substrate display an increased amount of receptor sites per area. Hence micro-structured nanoparticle layers form highly sensitive sensor surfaces for application in protein biochip technology. We will present results concerning the maintainance of protein function on nanoparticulate chip-surfaces, the dynamic range of nanoparticle-chips and chip-readout by fluorescence-detection or MALDI-mass-spectrometry.