Self-assembly of supramolecular triarylamine nanowires in mesoporous silica and biocompatible electrodes thereof

Abstract

Biocompatible silica-based mesoporous materials, which present high surface areas combined with uniform distribution of nanopores, can be organized in functional nanopatterns for a number of applications. However, silica is by essence an electrically insulating material which precludes applications for electro-chemical devices. The formation of hybrid electroactive silica nanostructures is thus expected to be of great interest for the design of biocompatible conducting materials such as bioelectrodes. Here we show that we can grow supramolecular stacks of triarylamine molecules in the confined space of oriented mesopores of a silica nanolayer covering a gold electrode. This addressable bottom-up construction is triggered from solution simply by light irradiation. The resulting self-assembled nanowires act as highly conducting electronic pathways crossing the silica layer. They allow very efficient charge transfer from the redox species in solution to the gold surface. We demonstrate the potential of these hybrid constitutional materials by implementing them as biocathodes and by measuring laccase activity that reduces dioxygen to produce water.

Triarylamine-Based Supramolecular Polymers: Structures, Dynamics, and Functions

“…19 Besides, TAA nanowires were built within insulating mesoporous silica layers in order to access an hybrid conducting material functioning as a biocathode. 34 In a complementary direction, the group of Sanvito investigated by DFT and Monte Carlo simulations the ability of TAA nanowires to behave as organic semiconductors for spintronic applications. 35 They reported on the finding of a spin diffusion length of 100 nm at room temperature, a rather large value compared to other organic materials.…”

Long-Range Energy Transport via Plasmonic Propagation in a Supramolecular Organic Waveguide

“…The molecular design and functionality of our waveguide is based on recent findings showing that triarylamine molecules, when properly substituted with amide groups, are able to strongly stack together in the form of various soft self-assemblies (e.g., rods, − fibers, − spheres, , in suspension or in confined space). Interestingly, we have demonstrated that in such stacked configurations, and when doped by triarylammonium radicals (by using, for instance, a simple photo-oxidation process in chlorinated solvents), , some of these structures present delocalized metallic electrons in the form of supramolecular polarons that provide them with exceptional conduction properties. ,, Very recently, we have also demonstrated the controlled attachment of soft triarylamine-based nanowires between plasmonic nanoclusters of gold and we have proved their functioning as organic plasmonic interconnects on the 100 nm scale .…”

Recent Advances on Stimuli‐Responsive Smart Materials and their Applications

“…The fabrication of triarylamine nanowires as biocathode device for O 2 reduction to water utilized and a high ohmic conductivity greater than 5 × 10 3 Sm 1 for triarylamine based nanowires suggest design of chemosensors and chemical surface imaging. [26] Subsequently, photoresponsive molecular actuators consisting of tetrasubstituted crowded alkene and dithienylethene as motor and modulator highlighted. UV light irradiation induces easy rotation of motor around the CÀ C single bonds whilst the cyclic modulator relieves the torsional strain across the backbone of polymer chain results contraction of polymer backbone.…”

“…The visible light irradiation of C12‐TAA in chloroform for 1 h results formation of nanowires less than 5 nm diameter within mesoporous silica confirmed by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The fabrication of triarylamine nanowires as biocathode device for O 2 reduction to water utilized and a high ohmic conductivity greater than 5×10 3 Sm 1 for triarylamine based nanowires suggest design of chemosensors and chemical surface imaging …”