Deposition and meniscus alignment of DNA-CNT on a substrate

We present a study of deposition and meniscus alignment of DNA-single walled carbon nanotube hybrids (DNA-CNT) on a silicon wafer coated with an alkyl-silane monolayer. We show that this process occurs in two stages: adsorption of DNA-CNT onto the hydrophobic surface and subsequent alignment by a passing meniscus. We study how pH, ionic strength, and time affect the density of nanotubes deposited on the surface. Experimental results are interpreted using models for the kinetics of deposition and for forces that affect alignment by the meniscus. We show that this method can be used to produce uniform global alignment of controlled density as well as controlled patterns, results that may be useful for applications such as CNT-based device construction.