Site-directed placement of three-dimensional DNA origami.

The combination of lithographic methods with two-dimensional DNA origami self-assembly has led, among others, to the development of photonic crystal cavity arrays and the exploration of sensing nanoarrays where molecular devices are patterned on the sub-micrometre scale. Here we extend this concept to the third dimension by mounting three-dimensional DNA origami onto nanopatterned substrates, followed by silicification to provide hybrid DNA-silica structures exhibiting mechanical and chemical stability and achieving feature sizes in the sub-10-nm regime. Our versatile and scalable method relying on self-assembly at ambient temperatures offers the potential to three-dimensionally position any inorganic and organic components compatible with DNA origami nanoarchitecture, demonstrated here with gold nanoparticles.

Transcript-activated collagen matrix as sustained mRNA delivery system for bone regeneration.

Transcript therapies using chemically modified messenger RNAs (cmRNAs) are emerging as safe and promising alternatives for gene and recombinant protein therapies. However, their applications have been limited due to transient translation and relatively low stability of cmRNAs compared to DNA. Here we show that vacuum-dried cmRNA-loaded collagen sponges, termed transcript activated matrices (TAMs), can serve as depots for sustained delivery of cmRNA.

Placing individual molecules in the center of nanoapertures.

While nanophotonic devices are unfolding their potential for single-molecule fluorescence studies, metallic quenching and steric hindrance, occurring within these structures, raise the desire for site-specific immobilization of the molecule of interest. Here, we refine the single-molecule cut-and-paste technique by optical superresolution routines to immobilize single fluorescent molecules in the center of nanoapertures. By comparing their fluorescence lifetime and intensity to stochastically immobilized fluorophores, we characterize the electrodynamic environment in these nanoapertures and proof the nanometer precision of our loading method.

Easy fabrication of electrically insulating nanogaps by transfer printing.

An easy and cost-effective method to reproducibly fabricate nanogaps over a large area is introduced. Gold is evaporated on low-aspect-ratio polydimethylsiloxane (PDMS) stamps at an angle of 60°. Afterwards, the stamp is brought into contact with a silicon/silicon dioxide substrate and subsequently peeled at rates varying from 1 to 3 mm s(-1), resulting in the fabrication of nanogaps between two gold electrodes.