Biomimetic nanolithography and its application for biosensor chipfabrication

摘要

Various nano-structures and complex patterns have been fabricated by top-down or bottom-up approaches, which have own strength and weakness. Here we combined the top-down and the bottom-up fabrications to take advantages on both strengths. We demonstrated that two different ways of the top-down/bottom-up combination could be very effective for the future nano-fabrications. One way is to assemble nanometer-sized building blocks into the device configurations such as electronics and sensor. Our strategy is to use those functionalized peptide nanowires, which can recognize and selectively bind a well-defined region on antigen-patterned substrates, as building blocks to assemble nanoscale architectures at uniquely defined positions, patterned by AFM-based nanolithography. The second method of the top-down/bottom-up combination is to pattern mineralization peptides with nanolithography and grow metals along the peptide lines. For example, when an Au-mineralizing peptide was written in the line-array, the biomineralization yielded monodisperse Au-NPs along the peptide lines. We were also succeeded to grow and pattern semiconductors at room temperature as precursors were patterned with dip-pen nanolithography. This crystallization was induced by energy gain from the shape change caused by DPN. Then, hydrophobic-hydrophilic pattern that mimics protein-binding sites in nature could be patterned by DPN and this pattern geometry can induce the attachment-detachment switching of proteins. At last, the electronic pathogen sensor chips will be introduced as another example for the DPN application. Here the DPN was applied to attach single cell at a time on transducer surface, which unambiguously determined the single cell detection limit of the sensors.