Si nanostructures: A new method for fabricating large‐area Si nanostructures in a high‐throughput fashion has been demonstrated. The procedure is based upon dip‐pen nanolithography in combination with wet‐chemical etching and reactive ion etching. Multipen techniques have been demonstrated for the fabrication of large‐area Si nanostructure arrays (see AFM image; dot 1: diameter/height=1460/140 nm; dot 9: diameter/height=385/75 nm).

A simple and novel method for fabricating poly(dimethylsiloxane) (PDMS)-coated dip pen nanolithography (DPN) stamp tips was developed. These kinds of tips absorb chemicals (“inks”) easily and allow one to generate molecule-based patterns in a conventional DPN experiment. The generated patterns also can be imaged with the same DPN stamp tips. This method is a type of scanning probe contact printing but provides the ability to generate higher resolution structures than one can obtain with the conventional technique, which thus far has only enabled micron scale patterning. Sub-100 nm resolution patterning with 16-mercaptohexadecanoic acid (MHA) as an ink is demonstrated with these novel tips and is comparable to what one can obtain with a conventional ink-coated Si3N4 probe tip. Proof-of-concept is also demonstrated with 1-octadecanethiol (ODT), dendrimers and cystamine as inks.

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In the present work the layer-by-layer nano-assembly technique was used for the development of complex catalytic microparticles on the basis of firefly luciferase (FL). FL films containing 1, 2, or 3 monolayers were assembled on silver electrode QCM-resonators and on 520-nm diameter sulfonated polystyrene latex by alternate adsorption of FL and polycations using electrostatic interactions for the interlayer interaction. The assembly process was studied with quartz crystal microbalance, UV-vis spectroscopy, and microelectrophoresis (surface potential). Structural studies of the resulting multilayers confirmed stepwise deposition of FL and cationic poly(dimethyldiallyl ammonium chloride) with a bilayer thickness of 14 nm; a systematic shift of the surface potential from +28 mV for poly(dimethyldiallyl ammonium chloride) to -14 mV for luciferase outermost layer was established. The functionality and stability of the biocolloids were demonstrated by monitoring the intensity of the light emission. Factors influencing the light emitted upon catalytic activity of FL such as the number of luciferase layers in the film and polyion layer at the outermost layer were studied.