Multiplexed dip pen nanolithography® patterning by simple desktop nanolithography platform

Multiplexed patterning in the micro-scale has been required in order to accomplish functional bio-materials templating on the subcellular length scale. Multiplexed bio-material patterns can be used in several fields: high sensitivity DNA/protein chip development, cell adhesion/differentiation studies, and biological sensor applications. Especially, two or more materials' patterning in subcellular length scale is highly demanding to develop a multi-functional and high-integrated chip device. The multiplexing patterning of two or more materials is a challenge because of difficulty in an alignment and a precision of patterning. In this work, we demonstrate that multiplexed dip pen nanolithography® (DPN®) patterning up to four different material inks by means of using recently developed new generation nanolithography platform (NLP 2000™, NanoInk, Inc., Skokie, IL). Ink materials were prepared by adding different colored fluorescent dyes to matrix carrier materials, such as poly(ethylene glycol) dimethacrylate (PEG-DMA) and lipid material (1,2-dioleoyl-sn-glycero-3-phosphocholine, DOPC). Finally, dot-array patterns of four different inks were obtained in 50 × 50 μm² area. This lithography platform is capable of patterning 12 separate materials within micrometer areas by efficient use of the available MEMS accessories. This number can be scaled up further with development of new accessories.