No abstract

Metal copper mesh with superhydrophobic and superoleophilic surface had been successfully fabricated via a facile solution-immersion process. The hierarchical structure was prepared on the commercial copper mesh surface by etching with the nitric acid. After being modified by 1-hexadecanethiol (HDT), the as-prepared mesh indicated both superhydrophobic and superoleophilic property simultaneously. This as-prepared metal mesh could then be applied for oil and water mixture separation. The unusual wettability of the as-prepared mesh was stable in corrosive conditions, such as acidic, basic, and salt solutions. The solution-immersion method was simple, time-saving, and inexpensive and therefore exhibited great potential application.

Dynamically imaging stochastic collision electrochemistry of single nanoparticles by electrochemiluminescence microscopy enables visualization of diverse collision behaviours.

A bio‐coreactant‐enhanced electrochemiluminescence (ECL) microscopy realizes the ECL imaging of intracellular structure and dynamic transport. This microscopy uses Ru(bpy)32+ as the electrochemical molecular antenna connecting extracellular and intracellular environments, and uses intracellular biomolecules as the coreactants of ECL reactions via a “catalytic route”. Accordingly, intracellular structures are identified without using multiple labels, and autophagy involving DNA oxidative damage is detected using nuclear ECL signals. A time‐resolved image sequence discloses the universal edge effect of cellular electroporation due to the influence of the geometric properties of cell membranes on the induced transmembrane voltage. The dynamic transport of Ru(bpy)33+ in the different cellular compartments unveils the heterogeneous intracellular diffusivity correlating with the actin cytoskeleton. In addition to single‐cell studies, the bio‐coreactant‐enhanced ECL microscopy is used to image a slice of a mouse liver and a colony of Shewanella oneidensis MR‐1.

A DNA configuration switch was designed to fabricate a reversible and regenerable Raman-active substrate. The substrate is composed of an Au film and hairpin-shaped DNA strand (hot spot generation probes, HSGPs) labeled with dye-functionalized silver nanoparticle (AgNP). Another ssDNA that recognizes a specific trigger was used as an antenna. The HSGPs are immobilized on the Au film to draw the dye-functionalized AgNPs close to the Au surface and create an intense electromagnetic field. Hybridization of HSGP with the two arm segments of the antenna forms a triplex-stem structure to separate the dye-functionalized AgNP from the Au surface and cause a quenching of the Raman signal. Interaction with its trigger leads to release of the antenna from the triplex-stem structure, and the hairpin structure of the HSGP is restored, thereby creating an effective “off” to “on” state of the Raman signal. Nucleic acid sequence associated with the HIV-1 U5 long terminal repeat sequences and ATP are used as the triggers. The substrate shows excellent reversibility, reproducibility and controllability of SERS effects, which are significant requirements for practical SERS sensor applications.