Writing Patterns of Molecules on Molecular Printboards

Abstract

Bottom-up nanotechnology has to start with the precise positioning of molecules. For this purpose we are developing molecular printboards, that is, self-assembled monolayers (SAMs) of molecules that have specific recognition sites, for example, molecular cavities, to which molecules can be anchored through specific and directional supramolecular interactions.[1] Such molecular printboards are prepared by the self-assembly of b-cyclodextrin (b-CD) derivatives on gold and silicon oxide surfaces. Herein we describe how to print or write, by microcontact printing (mCP) and dip-pen nanolithography (DPN), respectively, molecular patterns of guest-functionalized calixarene molecules, dendritic wedges labeled by fluorescent groups, and dendrimers on b-CDterminated printboards. The binding, as well as the desorption of the molecules, can be fine-tuned by chemical design, which allows virtually unlimited flexibility in the chemical functions that can be employed. These structures can be subsequently used to direct the adsorption of different materials, for example, fluorescent dyes.Microcontact printing has been developed by Whitesides for the preparation of patterns of molecules on bare surfaces by, for example, the transfer of thiols to gold substrates in the contact areas between a soft polymeric stamp and the substrate. [2,3] This has recently been extended by Mirkin and co-workers to writing with molecules on such surfaces by using the DPN approach.[4] Various types of molecules were deposited onto different substrates by DPN which led to arrays of, for example, DNA, [5] proteins, [6] and nanoparticles. [7] Registry capabilities have been demonstrated as well, [8] and a multipen nanoplotter able to produce parallel patterns with different ink molecules has been developed.[9]b-CD (1 a, Scheme 1) can act as a host for the binding of a variety of small, organic guest functionalities in water through hydrophobic interactions. We prepared self-assembled monolayers (SAMs) of a b-CD heptathioether adsorbate 1 b (Scheme 1) on gold as described before. [10,11] Such adsorbates form densely packed, well-ordered SAMs with equivalent

A Cyclodextrin Self-Assembled Monolayer (SAM) Based Surface Plasmon Resonance (SPR) Sensor for Enantioselective Analysis of Thyroxine

“…They have also been extensively used as chiral selectors in separation technology [18] and it has been shown that cyclodextrin based polymers could be used as sensitive layers in chiral sensing by SPR [16]. Reinhoudt has extensively studied the ability of these macrocycle to form well packed SAMs on gold surfaces [19][20][21][22][23][24].…”

Silver Containing Nanostructures from Hydrogen-bonded Supramolecular Scaffolds

“…As a natural phenomenon in biological [4] and chemical processes, [5] self-assembly offers attractive possibilities for creating functional molecular structures, for example artificial molecular machines [6]. Recent research interests are focused towards the fabrication, and specially positioning of noncovalent supramolecular aggregates on surfaces in organized networks [7][8][9][10][11]. Though many examples of supramolecular structures formed in situ on surfaces are known, only few superstructures formed in solution have been efficiently transferred onto surfaces [7,9, 11e, 12].…”

Combinatorial Fabrication of Fluorescent Patterns with Metal Ions Using Soft Lithography

“…[3] The targets printed on SAMs [3] vary from (bio)molecules of different size, to catalysts, [5] polymers, [6] and dendrimers, [7] and, only recently, metal salts. [8,9] lCP can also be used to construct functionalized patterns on a surface through the covalent attachment of molecules to a reactive monolayer, [10][11][12] or through noncovalent synthesis using supramolecular interactions for the immobilization of molecules on functionalized surfaces.…”

“…[8,9] lCP can also be used to construct functionalized patterns on a surface through the covalent attachment of molecules to a reactive monolayer, [10][11][12] or through noncovalent synthesis using supramolecular interactions for the immobilization of molecules on functionalized surfaces. [7] Many procedures for the direct fabrication and visualization of functional monolayer patterns often rely on specific binding between molecules. Specific interactions between antibodies and antigens are often used for the fabrication and visualization of patterned surfaces for biosensing applications.…”