Coupling nanomaterials with biomolecular recognition events represents a new direction in nanotechnology toward the development of novel molecular diagnostic tools. Here a graphene oxide (GO)‐based multicolor fluorescent DNA nanoprobe that allows rapid, sensitive, and selective detection of DNA targets in homogeneous solution by exploiting interactions between GO and DNA molecules is reported. Because of the extraordinarily high quenching efficiency of GO, the fluorescent ssDNA probe exhibits minimal background fluorescence, while strong emission is observed when it forms a double helix with the specific targets, leading to a high signal‐to‐background ratio. Importantly, the large planar surface of GO allows simultaneous quenching of multiple DNA probes labeled with different dyes, leading to a multicolor sensor for the detection of multiple DNA targets in the same solution. It is also demonstrated that this GO‐based sensing platform is suitable for the detection of a range of analytes when complemented with the use of functional DNA structures.

By incorporating cation-π interactions to classic all-atoms force fields, we show that there is a clear enrichment of Na+ on a carbon-based π electron-rich surface in NaCl solutions using molecular dynamics simulations. Interestingly, Cl− is also enriched to some extend on the surface due to the electrostatic interaction between Na+ and Cl−, although the hydrated Cl−-π interaction is weak. The difference of the numbers of Na+ and Cl− accumulated at the interface leads to a significant negatively charged behavior in the solution, especially in nanoscale systems. Moreover, we find that the accumulation of the cations at the interfaces is universal since other cations (Li+, K+, Mg2+, Ca2+, Fe2+, Co2+, Cu2+, Cd2+, Cr2+, and Pb2+) have similar adsorption behaviors. For comparison, as in usual force field without the proper consideration of cation-π interactions, the ions near the surfaces have a similar density of ions in the solution.

The reaction between CHO and OH radicals has been studied in a laser photolysis cell using the reaction of F atoms with CH and HO for the simultaneous generation of both radicals, with F atoms generated through 248 nm photolysis of XeF. An experimental setup combining cw-Cavity Ring Down Spectroscopy (cw-CRDS) and high repetition rate laser-induced fluorescence (LIF) to a laser photolysis cell has been used. The absolute concentration of CHO was measured by cw-CRDS, while the relative concentration of OH(v = 0) radicals was determined by LIF. To remove dubiety from the quantification of CHO by cw-CRDS in the near-infrared, its absorption cross section has been determined at 7489.16 cm using two different methods. A rate constant of k = (1.60 ± 0.4) × 10 cm s has been determined at 295 K, nearly a factor of 2 lower than an earlier determination from our group ((2.8 ± 1.4) × 10 cm s) using CHI photolysis as a precursor. Quenching of electronically excited I atoms (from CHI photolysis) in collision with OH(v = 0) is suspected to be responsible for a bias in the earlier, fast rate constant.

Dibenzothiophene (DBT) is oxidized to the corresponding sulfoxide and sulfone in an emulsion system (W/O) composed of polyoxometalate anion [C(18)H(37)N(CH(3))3](5)[PV(2)Mo(10)O(40)] as both the surfactant and catalyst, using molecular oxygen as the oxidant and aldehyde as the sacrificial agent under mild conditions.

In article number 1907818, Bo Song and co‐workers summarize the recent advances regarding the preparation and modulation strategies of electrocatalysts based on 2D transition metal dichalcogenides (TMDs). 2D TMDs are promising candidates for electrocatalytic water splitting, and the produced hydrogen (H2) and oxygen (O2) could be well utilized as continual power supply for space craft and life‐support system for astronauts, respectively. 2D‐TMDs‐based electrocatalysts with excellent catalytic performance could provide a promising solution for future interstellar exploration, such as to Mars.

Functional nanoscale structures consisting of a DNA molecule coupled to graphene or graphene oxide (GO) have great potential for applications in biosensors, biomedicine, nanotechnology, and materials science. Extensive studies using the most sophisticated experimental techniques and theoretical methods have still not clarified the dynamic process of single-stranded DNA (ssDNA) adsorbed on GO surfaces. Based on a molecular dynamics simulation, this work shows that an ssDNA segment could be stably adsorbed on a GO surface through hydrogen bonding and π-π stacking interactions, with preferential binding to the oxidized rather than to the unoxidized region of the GO surface. The adsorption process shows a dynamic cooperation adsorption behavior; the ssDNA segment first captures the oxidized groups of the GO surface by hydrogen bonding interaction, and then the configuration relaxes to maximize the π-π stacking interactions between the aromatic rings of the nucleobases and those of the GO surface. We attributed this behavior to the faster forming hydrogen bonding interaction compared to π-π stacking; the π-π stacking interaction needs more relaxation time to regulate the configuration of the ssDNA segment to fit the aromatic rings on the GO surface.

We herein report a power-free microfluidic chip for fluorescent DNA detection with high single-nucleotide polymorphism discrimination, using a DNA intercalator and graphene oxide.

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