This paper reports for the first time the electrogenerated chemiluminescence (ECL) behavior of graphite-like carbon nitride (g-C(3)N(4)) with K(2)S(2)O(8) as the coreactant. The possible ECL reaction mechanisms are proposed. The spectral features of the ECL emission and photoluminescence (PL) of g-C(3)N(4) are compared, and their resemblance demonstrates that the excited states of g-C(3)N(4) from both ECL and photoexcitation are the same. The effects of K(2)S(2)O(8) concentration, pH, g-C(3)N(4)/carbon powder ratio, and scan rate on the ECL intensity have been studied in detail. Furthermore, it is observed that the ECL intensity is efficiently quenched by trace amounts of Cu(2+). g-C(3)N(4) is thus employed to fabricate an ECL sensor which shows high selectivity to Cu(2+) determination. The limit of detection is determined as 0.9 nM. It is anticipated that g-C(3)N(4) could be a new class of promising material for fabricating ECL sensors.

CuO nanowires have been prepared and applied for the fabrication of glucose sensors with highly enhanced sensitivity. Cu(OH)(2) nanowires were initially synthesised by a simple and fast procedure, CuO nanowires were then formed simply by removing the water through heat treatment. The structures and morphologies of Cu(OH)(2) and CuO nanowires were characterised by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The direct electrocatalytic oxidation of glucose in alkaline medium at CuO nanowire modified electrodes has been investigated in detail. Compared to a bare Cu electrode, a substantial decrease in the overvoltage of the glucose oxidation was observed at the CuO nanowire electrodes with oxidation starting at ca. 0.10 V vs. Ag/AgCl (saturated KCl). At an applied potential of 0.33 V, CuO nanowire electrodes produce high and reproducible sensitivity to glucose with 0.49 microA/micromol dm(-3). Linear responses were obtained over a concentration range from 0.40 micromol dm(-3) to 2.0 mmol dm(-3) with a detection limit of 49 nmol dm(-3) (S/N = 3). The CuO nanowire modified electrode allows highly sensitive, low working potential, stable, and fast amperometric sensing of glucose, thus is promising for the future development of non-enzymatic glucose sensors.

The synthesis of water-soluble near-infrared (NIR)-emitting quantum dots (QDs) in aqueous solution has received much attention recently. However, the stabilizer 3-mercaptopropionic acid, commonly used in the synthesis of NIR-emitting QDs, is notorious for its toxicity and awful odor. Here we chose thiol ligand N-acetyl-L-cysteine (NAC) as the ideal stabilizer and have successfully employed it to synthesize high-quality NIRemitting CdTe/CdS QDs in a one-step process via a simple hydrothermal route. NAC possesses favorable properties such as nontoxic, nonvolatile, inexpensive, and good water-solubility. Our as-prepared NIR-emitting CdTe/CdS QDs exhibit high photoluminescence quantum yields (45-62%), narrow full-width at half-maximum, and high photostability, thanks to the formation of a protective CdS shell on the CdTe core through the decomposition of NAC in the hydrothermal route under high temperature. The prepared QDs can be applied for bioimaging due to its excellent water-solubility and biological compatibility. The core/shell structure of the NIR-emitting CdTe/CdS QDs was verified by X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, selected area electron diffraction, and X-ray powder diffraction. The formation mechanism of these QDs is discussed in detail.

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