A novel chemosensor based on graphitic carbon nitride quantum dots and potassium ferricyanide chemiluminescence system for Hg(II) ion detection

In this research, graphitic carbon nitride quantum dots (g-CNQDs) were prepared by a simple and one-step microwave-assisted approach and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The chemiluminescence (CL) emission of the synthesized g-CNQDs induced by K3Fe(CN)(6) as an oxidant along with the CL mechanism were investigated. Based on the diminishing effect of Hg(II) ion on the g-CNQDs-K3Fe(CN)(6) CL system, a simple and sensitive chemosensor was constructed for Hg(II) ion detection in aqueous solutions. A response surface methodology was used to optimize the experimental parameters affecting the analytical signal. Under the optimized experimental conditions, the calibration graph was linear in the range of 0.25-10 ng mL(-1) with a detection limit of 0.08 ng mL(-1). The inter-day and intra-day relative standard deviations for six replicate determinations of 4 ng mL(-1) Hg(II) ion were 3.4% and 2.8%, respectively. The developed method was successfully applied for the selective and sensitive determination of Hg(II) in water and food samples with recoveries in the range of 95.7-102.8% for the spiked samples. The accuracy of the method was evaluated by analyzing a certified reference material (SRM 1566b). (C) 2015 Elsevier B.V. All rights reserved.