Technique ‘prints’ stable nanopatterns

U. ILLINOIS—By combining the age-old manufacturing techniques of heat and chemistry with the cutting-edge capabilities of atomic force microscopy, researchers have developed a new method for manipulating, designing, and manufacturing complex nanostructures.

The technique, known as thermochemical nanolithography (TCNL), allows for low-cost, high-resolution patterning of stable, tailor-made nanostructures. Potential applications for the technology include protein detection chips and nanoelectronic devices.

Researchers at the University of Illinois and Georgia Tech report their findings in a paper published in the journal Advanced Functional Materials.

TCNL has several advantages over current methods such as dip-pen nanolithography or self-assembly for patterning at scales below 100nm. The TCNL method has a writing speed of one millimeter per second, and can create high-resolution patterns designed specifically for the requirements of scientists or manufacturers.

Another advantage is that the thermochemical nanolithographic method produces stable nanopatterns that are suitable for storage and future use. Due to the unique chemical stability of the patterns produced by the method, the researchers say that the resultant substrates can be stored for weeks and subsequently used for the selective attachment of nanometer-sized objects, such as proteins or DNA, using standard chemical protocols. This makes the method especially useful in the areas of protein and DNA nanolithography.

The new method demonstrated nanoscale chemical patterning of different chemical species (amine, thiol, aldehyde, and biotin) on a single chip in order to, as the authors write, “inscribe amine patterns followed by their chemical conversion to other functional groups.

“In particular the ability of this method to attach proteins and DNA to the chemical nanopatterns and to create co-patterns of two distinctive bioactive proteins is demonstrated.”

The method involves using an atomic force microscope to heat a silicon tip which directs multiple nanoscale chemical reactions on a single chip.

The researcher’s report examines the challenges faced in the nanoscale biotechnology and science realms when it comes to, as the authors write, manipulating and controlling “the surface positioning of individual proteins, nanoparticles, and other complex nanostructures.”

They add that achieving this aim “would greatly facilitate the development of protein chips with single molecule detection capability, nanoelectronics devices, and to assist in fundamental studies of complex cell–cell and cell–matrix interactions, such as the formation of immunological synapses and focal contacts.”

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