NanoPen for Patterning Nanoparticles

Frankly speaking, my first thought was that this paper is about a nanosized pen to arrange nanoparticles at the surface but when I read the whole things the phrases like “Don’t Judge a book by its cover” or “looks can be deceptive” starts popping up in my mind. The article is not about a tiny tiny pen but rather is about way of arranging nanoparticles in any patter.

Jokes aside, the work by Prof. Wu at Berkley is serious business and presents an easy way to pattern nanoparticles/ nanopatterns over large area not easily achieved by existing patterning tools like soft lithography, dip pen nanolithography or e-beam lithography. According to authors Nanopen is

“— a novel technique for low optical power intensity, flexible, real-time reconfigurable, and large-scale light-actuated patterning of single or multiple nanoparticles, such as metallic spherical nanocrystals, and one-dimensional nanostructures, such as carbon nanotubes”

By exploiting electrokinetic forces, Nanopen is capable of arranging nanoparticles over large surface area (thousands of square micrometers) within few seconds simply by using low power laser light, LEDs or just plain old halogen lamps. The power of Nanopen is shown by arranging 90nm gold nanoparticles in various shapes and sizes including logo of NIH, and a 10×10 array with each individual spots of 10-20µm in size. By placing gold-nanoparticles in close proximity with exact spatial control using NanoPen, authors were able to create ‘hot-spots’ for very sensitive detection of Rhodamine 6G using SERS (Surface Enhanced Raman Spectroscopy). I hope other types of sensors will follow soon.

Gold nanoparticles are extensively used for sensing applications and NanoPen technology opens up new avenues for exploiting these wonderful particles for designing novel biosensors. As noted by authors it is possible to integrate microfluidics channels with NanoPen writing platform to deliver gols nanoparticles activated with different ligands, proteins, DNAs or anything else to design multiplexed detection devices. Gold nanoparticles can also be decorated by various chemical reactive groups using self assembled monolayers (SAMs) of alkanethiols hence it is entirely possible to design a pattern using NanoPen and then use it as template for bottom-up fabrication.

I am no expert in microfabrication but looking at the device design it seems to me that multiple devices can be fabricated in chip format for simultaneous writing of multiple particle types at the same time.

Possibilities are immense but the question is can the technology translate out of lab to a real commercial instrument!


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