The demand for high-throughput electron tomography is rapidly increasing in biological and material sciences. However, this 3D imaging technique is computationally bottlenecked by alignment and reconstruction which runs from hours to days. We demonstrate real-time tomography with dynamic 3D tomographic visualization to enable rapid interpretation of specimen structure immediately as data is collected on an electron microscope. Using geometrically complex chiral nanoparticles, we show volumetric interpretation can begin in less than 10 minutes and a high-quality tomogram is available within 30 minutes. Real-time tomography is integrated into tomviz, an open-source and cross-platform 3D data analysis tool that contains intuitive graphical user interfaces (GUI), to enable any scientist to characterize biological and material structure in 3D.
Colloidal
crystal engineering with DNA has advanced beyond controlling
the lattice symmetry and parameters of ordered crystals to now tuning
crystal habit and size. However, the predominately used slow-cooling
procedure that enables faceted crystal habits also limits control
over crystal size and uniformity because nucleation and growth cannot
be separated. Here, we explore how DNA sequence design can be used
to deliberately separate nucleation and growth in a given crystallization
process. Specifically, two batches of complementary particles are
created with one batch exhibiting perfectly complementary base pairs
while the other has a strategically introduced mismatch. This design
enables the weaker binding “growth” particles to participate
in heterogeneous growth on the nucleates formed from the stronger
binding “seed” particles, effectively eliminating secondary
nucleation pathways. By eliminating secondary nucleation events, this
approach improves crystal uniformity, as measured by polydispersity
(from PDI = 0.201 to 0.091). By using this approach with two different
particle cores (gold and silver), we show how core–shell colloidal
crystals can be synthesized in a one-pot fashion. This work shows
how tuning DNA interaction strength can profoundly impact crystal
size, uniformity, and structure, parameters central to using such
materials as device components.
Megalibraries are centimeter-scale chips containing millions
of
materials synthesized in parallel using scanning probe lithography.
As such, they stand to accelerate how materials are discovered for
applications spanning catalysis, optics, and more. However, a long-standing
challenge is the availability of substrates compatible with megalibrary
synthesis, which limits the structural and functional design space
that can be explored. To address this challenge, thermally removable
polystyrene films were developed as universal substrate coatings that
decouple lithography-enabled nanoparticle synthesis from the underlying
substrate chemistry, thus providing consistent lithography parameters
on diverse substrates. Multi-spray inking of the scanning probe arrays
with polymer solutions containing metal salts allows patterning of
>56 million nanoreactors designed to vary in composition and size.
These are subsequently converted to inorganic nanoparticles via reductive
thermal annealing, which also removes the polystyrene to deposit the
megalibrary. Megalibraries with mono-, bi-, and trimetallic materials
were synthesized, and nanoparticle size was controlled between 5 and
35 nm by modulating the lithography speed. Importantly, the polystyrene
coating can be used on conventional substrates like Si/SiOx, as well as substrates typically more difficult to pattern on, such
as glassy carbon, diamond, TiO2, BN, W, or SiC. Finally,
high-throughput materials discovery is performed in the context of
photocatalytic degradation of organic pollutants using Au–Pd–Cu
nanoparticle megalibraries on TiO2 substrates with 2,250,000
unique composition/size combinations. The megalibrary was screened
within 1 h by developing fluorescent thin-film coatings on top of
the megalibrary as proxies for catalytic turnover, revealing Au0.53Pd0.38Cu0.09-TiO2 as the
most active photocatalyst composition.
The demand for high-throughput electron tomography is rapidly increasing in biological and material sciences. However, this 3D imaging technique is computationally bottlenecked by alignment and reconstruction which runs from hours to days. We demonstrate real-time tomography with dynamic 3D tomographic visualization to enable rapid interpretation of specimen structure immediately as data is collected on an electron microscope. We show volumetric interpretation can begin in less than 10 minutes and a high-quality tomogram is available within 30 minutes. Real-time tomography is integrated into tomviz, an open-source and cross-platform 3D data analysis tool that contains intuitive graphical user interfaces (GUI), to enable any scientist to characterize biological and material structure in 3D.
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