2 research outputs found
Engineering Photosystem I Complexes with Metal Oxide Binding Peptides for Bioelectronic Applications
Conventional
dye-sensitized solar cells comprise semiconducting
anodes sensitized with complex synthetic organometallic dyes, a platinum
counter electrode, and a liquid electrolyte. This work focuses on
replacing synthetic dyes with a naturally occurring biological pigment–protein
complex known as Photosystem I (PSI). Specifically, ZnO binding peptides
(ZOBiP)-fused PSI subunits (ZOBiP–PsaD and ZOBiP–PsaE)
and TiO<sub>2</sub> binding peptides (TOBiP)-fused ferredoxin (TOBiP–Fd)
have been produced recombinantly from Escherichia coli. The MOBiP-fused peptides have been characterized via western blotting,
circular dichroism, MALDI-TOF, and cyclic voltammetry. ZOBiP–PSI
subunits have been used to replace wild-type PsaD and PsaE, and TOBiP–Fd
has been chemically cross-linked to the stromal hump of PSI. These
MOBiP peptides and MOBiP–PSI complexes have been produced and
incubated with various metal oxide nanoparticles, showing increased
binding when compared to that of wild-type PSI complexes
Size- and Shape-Controlled Synthesis and Properties of Magnetic–Plasmonic Core–Shell Nanoparticles
Magnetic–plasmonic core–shell
nanomaterials offer
a wide range of applications across science, engineering, and biomedical
disciplines. However, the ability to synthesize and understand magnetic–plasmonic
core–shell nanoparticles with tunable sizes and shapes remains
very limited. This work reports experimental and computational studies
on the synthesis and properties of iron oxide–gold core–shell
nanoparticles of three different shapes (sphere, popcorn, and star)
with controllable sizes (70 to 250 nm). The nanoparticles were synthesized
via a seed-mediated growth method in which newly formed gold atoms
were added onto gold-seeded iron oxide octahedrons to form a gold
shell. The evolution of the shell into different shapes was found
to occur after the coalescence of gold seeds, which was achieved by
controlling the amount of additive (silver nitrate) and reducing agent
(ascorbic acid) in the growth solution. First-principles calculation,
together with experimental results, elucidated the intimate roles
of thermodynamic and kinetic parameters in the shape-controlled synthesis.
Both discrete dipole approximation calculation and experimental results
showed that the nanopopcorns and nanostars exhibited red-shifted plasmon
resonance compared with the nanospheres, with the nanostars giving
multispectral feature. This research has made a great step further
in manipulating and understanding magnetic–plasmonic hybrid
nanostructures and will make an important impact in many different
fields