Selective Functionalization of Tailored Nanostructures

Abstract

The controlled positioning of nanostructures with active molecular components is of importance throughout nanoscience and nanotechnology. We present a novel three-step method to produce nanostructures that are selectively decorated with functional molecules. We use fluorophores and nanoparticles to functionalize SiO features with defined shapes and with sizes ranging from micrometers to 25 nm. The method is called MACE-ID: molecular assembly controlled by electron-beam-induced deposition. In the first step, SiO nanostructures are written with focused electron-beam-induced deposition, a direct-writing technique. In the second step, the deposits are selectively silanized. In the final step, the silanes are functionalized with fluorescent dyes, polystyrene spheres, or gold nanoparticles. This recipe gives exciting new possibilities for combining the highly accurate control of top-down patterning (e-beam direct writing) with the rich variety of the bottom-up approach (self-assembly), leading to active or responsive surfaces. An important advantage of MACE-ID is that it can be used on substrates that already contain complex features, such as plasmonic structures, nanoantennas, and cavities.

Direct-Write Deposition and Focused-Electron-Beam-Induced Purification of Gold Nanostructures

“…16 Recently, FEBID has been used in advanced nanodevices, e.g., to stabilize the polarization of vertical cavity surface-emitting lasers 17 or to fabricate ultrasmall Hall sensors 18 and nanomagnet logic devices. 19 …”

“…16 Recently, FEBID has been used in advanced nanodevices, e.g., to stabilize the polarization of vertical cavity surface-emitting lasers 17 or to fabricate ultrasmall Hall sensors 18 and nanomagnet logic devices. 19 Among all FEBID materials, gold (Au) seems to be one of the most appealing substances because it possesses favorable chemical, electrical, and optical properties.…”

Sub-10 nm writing: focused electron beam-induced deposition in perspective

“…For research purposes, focused electron beam-induced deposition offers significant flexibility, making it attractive for explorative work. It is used for instance for the directed self-assembly of functional molecules [40], depositing seeds for nanowire growth [41] and, similar to the industrial application, contacting nanoscale devices [38].…”

Selective nucleophilic additions to poly(methacrylate)s containing isothiocyanate moieties in the side chains and their application in cross-linking

“…Using this reaction selectivity, isothiocyanate is applied to structure determination of proteins, which is known as the Edman degradation method . In addition, fluorescein isothiocyanate (FITC) is used as fluorescent indicator of primary amines . Although there are a lot of compounds having isothiocyanato groups, few polymers have isothiocyanato groups in the side chains…”