Site-Directed Exchange Studies with Combinatorial Libraries of Nanostructures

Abstract

We describe a new combinatorial method for studying the exchange between solution adsorbates and nanoscale features within libraries generated via dip-pen nanolithography. Four different compounds, 1-octadecanethiol, 16-mercaptohexadecanoic acid, ferrocene (11-mercaptoundecyl), and ferrocene (11-mercapto-1-oxoundecyl), are studied on amorphous and single-crystal gold substrates. This series of adsorbates allows us to compare the exchange properties of patterns of nanoscale features as a function of composition, feature size, and type of underlying substrate. Moreover, these properties can be compared and contrasted with bulk SAM properties. The novel strategy provides not only a method for initiating site-specific exchange processes but also a way of extracting kinetic information about the rate of such processes in situ.

Multiplexed Lipid Dip‐Pen Nanolithography on Subcellular Scales for the Templating of Functional Proteins and Cell Culture

“…Dip‐pen nanolithography (DPN) is a suitable method for the direct patterning of lipid membrane components19 and combinatorial libraries of bioactive and inactive structures in general 20–22. By using the tip of an atomic force microscope as an ultrasharp pen to locally deliver molecular inks to a surface, DPN has the unique potential to combine the resolution of electron‐beam lithography with the integration capabilities of ink‐jet printing at a throughput on the scale of microcontact printing 23–28. DPN has been used both for the direct, nanoscale deposition of functional proteins29–31 as well as for the fabrication of biochemical templates for selective adsorption 32–38.…”

The Evolution of Dip‐Pen Nanolithography.

“…DPN is compatible with many inks, from small organic molecules [1][2][3][4][5][6][7][109][110][111] to organic [8][9][10] and biological [11,12] polymers (Figure 2 C, D), and from colloidal particles [13,31,65] to metal ions [14][15][16] and sols. [17,18,112] DPN can be used to pattern surfaces ranging from metals to insulators and to pattern on top of functional monolayers adsorbed on a variety of surfaces.…”

Advantages of a Programmed Surface Designed by Organic Monolayers

“…Thus far, a SAM system using a combination of thiol-ink and gold-substrate, i.e., ink-paper chemistry, has already satisfied this requirement. Actually, Mirkin and co-workers produced a microarray of four different alkanethiol SAMs by DPN [7]. The chemical functionalization of the gold surface allows the use of surface plasmon resonance and an oxidation-reduction potentiometer to detect the chemical or biomolecular interaction on thiol-template.…”