A novel method has been developed for the preparation of crystalline nanotubes of copper selenide (CuSe). The method was based on template-directed synthesis in which the trigonal Se nanotubes were used as a template-directed reagent. Apart from CuSe nanotubes, one-direction (1D) nanocrystallites of Cu 3 Se 2 , Cu 2-x Se, and Cu 2 Se were also obtained by changing the atom ratio of Cu and Se in the precursors. The products were characterized by scanning electron microscopy (SEM), X-ray diffractometry (XRD), laser Raman spectrography (LRS), and X-ray photoelectron spectroscopy (XPS). On the basis of a series of experiments and characterizations, the formation mechanism of the CuSe nanotubes is discussed.

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Single-cell imaging is essential for elucidating the biological mechanism of cell function because it accurately reveals the heterogeneity among cells. The electrochemiluminescence (ECL) microscopy technique has been considered a powerful tool to study cells because of its high throughput and zero cellular background light. However, since cells are immobilized on the electrode surface, the steric hindrance and the insulation from the cells make it difficult to obtain a luminous cell ECL image. To solve this problem, direct ECL imaging of a single cell was investigated and achieved on chitosan and nano-TiO modified fluoride-doped tin oxide conductive glass (FTO/TiO/CS). The permeable chitosan film is not only favorable for cell immobilization but also increases the space between the bottom of cells and the electrode; thus, more ECL reagent can exist below the cells compared with the cells on a bare electrode, which guarantees the high sensitivity of quantitative analysis. The modification of nano-TiO strengthens the ECL visual signal in luminol solution and effectively improves the signal-to-noise ratio. The light intensity is correlated with the HO concentration on FTO/TiO/CS, which can be applied to analyze the HO released from cells at the single-cell level. As far as we know, this is the first work to achieve cell ECL imaging without the steric hindrance effect of the cell, and it expands the applications of a modified electrode in visualization study.

Using the super valence bond model, a generalized chemical picture for the electronic shells of an Au20 pyramid is given. It is found that Au20 can be viewed to be a superatomic molecule, of which its superatomic 16c-16e core (T) is in D(3)S hybridization bonded with four vertical Au atoms for the molecule-like (TAu4) electronic shell-closure. Based on such a superatom-atom bonding model, TX4 (X = F, Cl, or Br) are predicted to be very stable. Such a superatom-atom T-Au/T-X bonding enriches the scope of chemistry.