Tom Brown, Eric Harris, and Charles Pettijohn provided valuable unpublished correlations for use in the meta-analysis. The authors also gratefully acknowledge the helpful comments of David Ford, the anonymous JMR reviewers, and the late Dick Wittink.

Synthesizing plasmonic nanostructures in an ultraprecise manner is of paramount importance because the nanometer-scale structural details can significantly affect their plasmonic properties. Au nanocubes (AuNCs) have been a highly promising, heavily studied nanostructure with high potential in various fields, but an ultraprecise synthesis from 10 to 100 nm in size over a large number of AuNCs has not been well established. Precisely structured AuNC-based studies for a highly reproducible, quantitative plasmonic signal generation [e.g., quantitative surface-enhanced Raman scattering (SERS)] are needed for reliable use and exploration in the beneficial properties of AuNCs. Here, we developed a strategy for AuNC synthesis with the desired size and shape, ranging from 17 to 78 nm particularly with highly controlled corner sharpness, by precisely controlling the growth rate of different facets and AuNC-specific flocculation which enabled ultrahigh yields (∼98-99%). Importantly, the precisely shaped AuNCs can scatter light in a spectrally reproducible manner, and the SERS enhancement factors (EFs) for the AuNC dimers are very narrowly distributed (the EFs of 72 nm sharp-cornered cube dimers have a distribution within 1 order of magnitude). Our results pave the paths to ultrahigh yield synthesis of metal nanocubes with a precise size and shape and offer single-particle-level spectral controllability and reproducibility over a large number of particles.

The application scope of plasmonic nanostructures is rapidly expanding to keep pace with the ongoing development of various scientific findings and emerging technologies. However, most plasmonic nanostructures heavily depend on rare, expensive, and extensively studied noble metals such as Au and Ag, with the limited choice of elements hindering their broad and practical applications in a wide spectral range. Therefore, abundant and inexpensive nonnoble metals have attracted attention as new plasmonic nanomaterial components, allowing these nonnoble-metal-based materials to be used in areas such as photocatalysis, sensing, nanoantennas, metamaterials, and magnetoplasmonics with new compositions, structures, and properties. Furthermore, the use of nonnoble metal hybrids results in newly emerging or synergistic properties not observed from single-metal component systems. Here, the synthetic strategies and recent advances in nonnoble-metal-based plasmonic nanostructures comprising Cu, Al, Mg, In, Ga, Pb, Ni, Co, Fe, and related hybrids are highlighted, and a discussion and perspectives in their synthesis, properties, applications, and challenges are presented.

Collectively, ASC transplantation slowed striatal degeneration and behavioral deterioration of HD models, possibly via secreted factors.

MicroRNA has been identified as a potential biomarker because expression level of microRNA is correlated with various cancers. Its detection at low concentrations would be highly beneficial for cancer diagnosis. Here, we develop a new type of a DNA-modified gold nanoparticle-based bio-barcode assay that uses a conventional gel electrophoresis platform and potassium cyanide chemistry and show this assay can detect microRNA at aM levels without enzymatic amplification. It is also shown that single-base-mismatched microRNA can be differentiated from perfectly matched microRNA and the multiplexed detection of various combinations of microRNA sequences is possible with this approach. Finally, differently expressed microRNA levels are selectively detected from cancer cells using the bio-barcode gel assay, and the results are compared with conventional polymerase chain reaction-based results. The method and results shown herein pave the way for practical use of a conventional gel electrophoresis for detecting biomolecules of interest even at aM level without polymerase chain reaction amplification.