Silica Mineralization of DNA-Inspired 1D and 2D Supramolecular Polymers

Increasing Dimensionality in Self-Assembly: Toward Two-Dimensional Supramolecular Polymers

Different approaches to achieve 2D supramolecular polymers, as an alternative to the covalent bottom-up approaches reported for the preparation of 2D materials, are reviewed. The significance of the operation of weak non-covalent forces to induce a lateral growth of a number of self-assembling units is collected. The examples of both thermodynamically and kinetically controlled formation of 2D supramolecular polymers showed in this review demonstrate the utility of this strategy to achieve new 2D materials with biased morphologies (nanosheets, scrolls, porous surfaces) and showing elegant applications like chiral recognition, enantioselective uptake or asymmetric organic transformations. Furthermore, elaborated techniques like seeded or living supramolecular polymerizations have been demonstrated to give rise to complex 2D nanostructures.

Chiral optical scattering from helical and twisted silica nanoribbons

Helical and twisted silica nanoribbons, deposited in an in-plane direction and with a random orientation, on a quartz substrate showed chiral optical scattering, and the helical nanoribbons had a g-factor of the order of 10^-2 below 250 nm. Their signs depend on the handedness of the nanohelices. The effect of the morphology and the orientation of the helices on the chiral optical scattering were investigated with simulations via the boundary element method.

DNA Ring-Opening Polymerization Driven by Base Stacking

Supramolecular polymers, relying on reversible intermolecular interactions, promise a wide range of applications, including optoelectronic materials, self-healing materials, and biomedical delivery materials. Among potential molecular candidates, DNA strands act as an excellent platform. DNA has a well-established secondary structure (double helix), and its intermolecular interactions can be readily thermodynamically engineered and kinetically controlled. Extensive studies have demonstrated that various DNA motifs can polymerize/assemble into large polymers with different topology, geometry, and dimensionalities. Most of the reported polymerization is driven by hybridization of DNA strands. Herein, we report a novel system of DNA supramolecular polymerization that is driven by DNA base stacking. The polymerization has been confirmed by native polyacrylamide gel electrophoresis (PAGE) and atomic force microscopy (AFM). We believe that this work will expand the toolbox for DNA supramolecular polymerization and would, with further development, increase further control of DNA supramolecular polymerization.

A Programmable DNA-Silicification-Based Nanocavity for Single-Molecule Plasmonic Sensing

Plasmonic nanocavities are highly desirable for optical sensing because of their singular ability to confine light into deep subwavelength volumes. Yet, it remains profoundly challenging to fabricate structurally resilient nanocavities with high fidelity, and to obtain direct, noninvasive visualization of the plasmonic hotspots within such constructs. Herein, highly precise and robust nanocavities, entitled DNA-silicified template for Raman optical beacon (DNA-STROBE), are engineered by using silicified DNA scaffolds for spatial organization of discrete plasmonic nanoparticles. In addition to substantially enhancing structural stability and chemical inertness, DNA silicification significantly improves nanogap control, resulting simultaneously in large and controlled local electromagnetic field enhancement. The ultrasmall mode volume of the DNA-STROBE constructs promotes single-molecule occupancy enabling surface-enhanced Raman spectroscopy (SERS) observations of single-molecule activity even at elevated background concentration, significantly relaxing the restrictive pico- to nanomolar molecular concentration condition typically required for such investigations. Additionally, leveraging super-resolution SERS measurements allows noninvasive and diffraction-unlimited spatial profiling of otherwise unresolvable plasmonic hotspots. The highly programmable and reproducible nature of the DNA-STROBE, coupled with its quantitative label-free molecular readouts, provides a versatile platform with applications across the spectrum of nanophotonics and biomedical sciences.

DNA-inspired oligomers: from oligophosphates to functional materials

Replacement of the natural nucleotides in DNA by non-nucleosidic building blocks leads to phosphodiester-linked oligomers with a high functional diversity.

High definition polyphosphoesters: between nucleic acids and plastics

Nucleic acids and synthetic polyphosphoester materials have been distinct fields – this review shows how these areas now comprise a continuum.

Silica Mineralization of DNA-Inspired 1D and 2D Supramolecular Polymers

The preparation of hybrid materials from supramolecular polymers through the sol‐gel process is presented. Supramolecular polymers are assembled from phosphodiester‐linked pyrene oligomers and act as water‐soluble one‐ or two‐dimensional templates for silicification. The fibrillary and planar morphologies of the assemblies, as well as the excitonic interactions between the chromophores, remain unaffected by the silicification process.