Complex DNA Nanostructures from Oligonucleotide Ensembles

The first synthetic DNA nanostructures were created by self-assembly of a small number of oligonucleotides. Introduction of the DNA origami method provided a new paradigm for designing and creating two- and three-dimensional DNA nanostructures by folding a large single-stranded DNA and ‘stapling’ it together with a library of oligonucleotides. Despite its power and wide-ranging implementation, the DNA origami technique suffers from some limitations. Foremost among these is the limited number of useful single-stranded scaffolds of biological origin. This report describes a new approach to creating large DNA nanostructures exclusively from synthetic oligonucleotides. The essence of this approach is to replace the single-stranded scaffold in DNA origami with a library of oligonucleotides termed “scaples” (<u>sca</u>ffold sta<u>ples</u>). Scaples eliminate the need for scaffolds of biological origin and create new opportunities for producing larger and more diverse DNA nanostructures as well as simultaneous assembly of distinct structures in a “single-pot” reaction

Cottonwood-shaped plastic leaves mounted on aluminum trellis.

<p>Output from each Kynar-based petiole was rectified before summation over leaf population.</p

Power generation by a stack of 10 PVDF elements attached to base of 48 cm cattail-inspired model, flexed at 1.3 Hz by a gated air stream (11 knots).

<p>Individual elements connected in parallel to increase C step-wise. Approximate ten-fold increase in power with ten-fold increase in C. For R_L = 1 MΩ, Fc = 16.7, 2.3 and 1.7 Hz at 1, 7 and 10 elements connected in parallel.</p

Directional sensitivity of power output from vertical flapping stalk and cottonwood leaf models.

<p>Power was maximal for both systems when PVDF petiole was oriented edge-on into wind (8.9 vs. 7.5 knots for flapper vs. cottonwood) and decayed with increase in azimuthal angle. Max power was greater but decayed more steeply for vertical flapping stalk. R_L = 10 MΩ both systems.</p

Effect of excitation frequency and load resistance on power output from PVDF strip exposed to repetitive pulses of N₂ gas at 34 PSI.

<p>Optimal R_L corresponds to capacitive reactance of piezo. Sweet spot appears to exist at ~ 4 Hz, perhaps due to mechanical resonance.</p