Search

Fluorescent carbon dots (CDs) were successfully synthesized viapyrolysis of Setcreasea purpurea boom, providing a simple and convenient method for the preparation of CDs without using toxic or expensive materials. The as-synthesized CDs exhibit excellent water-soluble property, good photostability, and higher fluorescence quantum yield (18%), which makes the as-obtained CDs serve as fluorescent inks for printing luminescent patterns for anti-counterfeiting. In addition, the fabricated CDs have sensitive and selective response to molecular bromine (Br2) and have been successfully used for the detection of Br2in brine, which is based on the Br2-induced fluorescence quenching of CDs. According to UV-visible and transient state fluorescence spectroscopy, the fluorescence quenching of as-prepared CDs was due to the dynamic collision between the CDs and Br2.

We report on a non-enzymatic glucose sensor that was fabricated by growing CuO–Ag2O nanoparticles on a AgCuZn alloy substrate. The electrode material was characterized by X-ray diffraction, energy dispersive X-ray spectroscopy and scanning electron microscopy. Electrocatalytic oxidation of glucose can be performed at a potential of 0.45 V where the sensor exhibits a sensitivity as high as 3130 μA cm−2mM−1. It also shows a wide and linear response, a fast amperometric response, a dynamic range from 0.4 μM to 3.0 mM, a detection limit of 98 nM (at S/N= 3) and a good selectivity. In addition, the function of each component in the alloy is also explained in this work. Furthermore, this non-enzymatic glucose sensor provides a significant degree of accuracy when tested on real samples.

A rhodamine B thiohydrazide-based fluorescent turn-on chemosensor (RN2) for Hg2+was designed and described. RN2 exhibited very high sensitivity and selectivity towards Hg2+over other metal ions. Due to the opening of the spiro ring in rhodamine B caused by Hg2+, the RN2 displayed selective ‘off–on’ type fluorescence enhancement and a distinct color change. The results of biological imaging studies demonstrated that this probe was cell permeable and could be used as a fluorescent probe for monitoring Hg2+in living cells. The as-prepared chemosensor was also successfully applied to detect Hg2+in environmental water samples.