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Nanogold may not glitter, but its presence significantly improves the specificity and yield of PCR reactions owing to the greater affinity of gold nanoparticles to single‐stranded DNA than to double‐stranded DNA which helps to reduce mispairing. Indeed, gel electrophoresis shows a single predominant band for the target DNA obtained by this method, in contrast to streaking bands for products obtained by conventional PCR (lanes 1 and 2; see image).

Nanogold glänzt vielleicht nicht, aber seine Gegenwart verbessert Spezifität und Ausbeute von PCR‐Reaktionen erheblich. Grund ist die größere Affinität von Goldnanopartikeln zu Einzelstrang‐ als zu Doppelstrang‐DNA, was zu weniger Fehlpaarungen führt. Entsprechend tritt bei der Gelelektrophorese eine einzige Bande für die mit diesem Verfahren erhaltene Ziel‐DNA auf, während konventionelle PCR verwaschene Produktbanden liefert (Spuren 1, 2 im Bild).

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Cation-π or cation-π-π interaction between one cation and one or two structures bearing rich π-electrons (such as benzene, aromatic rings, graphene, and carbon nanotubes) plays a ubiquitous role in various areas. Here, we analyzed a new type interaction, cation⊗3π, whereby one cation simultaneously binds with three separate π-electron-rich structures. Surprisingly, we found an anomalous increase in the order of the one-benzene binding strength of the cation⊗3π interaction, with K(+) > Na(+) > Li(+). This was at odds with the conventional ranking of the binding strength which usually increases as the radii of the cations decrease. The key to the present unexpected observations was the cooperative interaction of the cation with the three benzenes and also between the three benzenes, in which a steric-exclusion effect between the three benzenes played an important role. Moreover, the binding energy of cation⊗3π was comparable to cation⊗2π for K(+) and Na(+), showing the particular importance of cation⊗3π interaction in biological systems.

A simple fluorescent sensor for water content based on carbon quantum dots with yellow fluorescence was first demonstrated.

A combination of ab initio calculations, circular dichroism, nuclear magnetic resonance, and X-ray photoelectron spectroscopy has shown that aluminum ions can induce the formation of backbone ring structures in a wide range of peptides, including neurodegenerative disease related motifs. These ring structures greatly destabilize the protein and result in irreversible denaturation. This behavior benefits from the ability of aluminum ions to form chemical bonds simultaneously with the amide nitrogen and carbonyl oxygen atoms on the peptide backbone.