Fluorescence covalent interaction enhanced sensor for lead ion based on novel graphitic carbon nitride nanocones.

Novel graphitic carbon nitride nanocones (g-CNNCs) were synthesized for the first time in this study. The SEM, TEM, XPS and FT-IR were used to research the structure of the g-CNNCs. We found that the g-CNNCs showed high selective and sensitive for fluorescence enhancement detection of Pb2+ ion via covalent interaction. In addition, the g-CNNCs exhibit stable and specific concentration-dependent fluorescence intensity in the presence of Pb2+ ion in the range of 1-200 µmol·dm-3, and the limit of detection was estimated to be 0.0438 µmol·dm-3 (3S/k). More importantly, the g-CNNCs were used to detect practical samples with satisfactory results.

Fast synthesis of porous copper nanoclusters for fluorescence detection of iron ions in water samples.

Copper nanoclusters (Cu NCs) have attracted great research interest in recent years owing to its unique physical, electrical and optical properties. Macromolecules have been widely used as templates to synthesize fluorescent Cu NCs. In this study, a simple method for synthesis of albumin chicken egg capped porous copper nanoclusters (p-Cu NCs) was developed for the first time. The obtained p-Cu NCs exhibited intense emission and excitation peaks at 280 nm and 340 nm, respectively. Besides, the p-Cu NCs fluorescence probe could be quenched by Fe3+ ions in aqueous solutions. Therefore, the p-Cu NCs can be excellently candidated as fluorescent probe for the detection of Fe3+ ions. Under optimized conditions, this fluorescent probe exhibited a wide linear response concentration range (0.2 to 100 µM) to Fe3+ with a detection limit of 0.0234 µM. In addition, the fluorescent probe has been successfully used for the detection of Fe3+ in natural water samples with satisfactory result.