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We herein communicate the DNase I like activity of nanoceria (CeO2 nanoparticles). Both CeO2 and DNase I cleave polyadenine (poly-A) DNA down to ∼5-mer fragments as the major products, although further cleavage to even shorter fragments was observed with CeO2. Mass spectrometry indicates a hydrolytic cleavage mechanism instead of oxidative cleavage.

Oxidase-mimicking nanozymes are attractive since they do not require H2O2, but such examples are quite rare. In particular, few can catalyze oxidation of fluorogenic substrates. We herein communicate that NiO nanoparticles are an oxidase nanozyme at physiological pH for fluorogenic Amplex red. Its activity is much higher than that of the commonly used nanoceria. This finding fills an urgent gap for biosensor development and intracellular imaging for the nanozyme field.

A water-soluble nanocarrier for a photo-activated CO releasing moiety (photoCORM) that can be triggered with NIR excitation is described. This has an upconversion nanoparticle core encapsulated by an amphiphilic polymer imparting both water solubility and a hydrophobic interior containing the photoCORM trans-Mn(bpy)(PPh3)2(CO)2. Such an ensemble offers a unique strategy for CO delivery to biological targets.

Using sensitized Tb(3+) luminescence spectroscopy as a tool, binding of 14 lanthanides to a lanthanide-dependent DNAzyme is studied, where the binding affinity is symmetric across the series and the tightest binding occurs with Nd(3+) and Ho(3+). This trend does not correlate with DNAzyme activity, suggesting that metal binding may not be the rate-limiting step of the DNAzyme catalysis.

By splitting the catalytic core of DNAzymes into two halves, two Pb(2+)-specific DNAzymes retain partial activity, while they show opposite trends of activity as a function of the split site, revealing important nucleotides for catalysis and metal binding.

The reaction between cisplatin and DNA is conveniently studied using fluorescently labeled oligonucleotides and gel electrophoresis; as an example of application, the inhibition of this reaction by citrate is demonstrated, which might increase selectivity of cisplatin towards guanine over adenine.

The partition of oligonucleotides and DNA staining dyes into a few hydrophobic ionic liquids has been studied, where the oligonucleotides remain in the aqueous phase and all the DNA staining dyes are extracted in the ionic liquid phase, allowing the separation of these two.

Silica-encapsulated Raman-reporter embedded SERS nanoprobes, named nanoaggregate embedded beads (NAEBs), were conjugated to the Salmonella specific tailspike protein (TSP) isolated from the P22 bacteriophage to enable a highly specific and ultrasensitive optical transduction platform. We demonstrate three successful surface conjugation strategies and highlight the detection of a single bacterium using SERS., (This journal is © The Royal Society of Chemistry 2012)