A Ratiometric Fluorescence Universal Platform Based on N, Cu Codoped Carbon Dots to Detect Metabolites Participating in H2O2-Generation Reactions

In this work, a new kind N, Cu codoped carbon dots (N/Cu-CDs) was prepared via a facile one-pot hydrothermal method by using citric acid monohydrate, copper acetate monohydrate and diethylenetriamine. The prepared N/Cu-CDs with a high quantum yield (50.1%) showed excitation-independent emission at 460 am. The structure and fluorescence properties of N/Cu-CDs were characterized by high-resolution transmission electron microscopy, fluorescence spectrofluorometr, FT-IR spectrometer, UV-visible spectrophotometer and photoelectron spectroscopy. N/Cu-CDs were applied, to establishing a ratiometric fluorescence probe toward 1%02 based on the inner filter effect (IFE) between N/Cu-CDs and DAP (2,3-diaminophenazine, the :oxidative product Of o-phenylenediamine (OPD)), and provided a ratiometric fluorescence universal platform for detection of the metabolites participating in H2O2-generation reactions (cholesterol and xanthine). The proposed method was demonstrated to be ultrasensitive and highly selective for cholesterol and xanthine assay with detection limits of 0:03 and 0.10 mu M, respectively. The fluorescence, probe built was applied to the determination of cholesterol and xanthine in human serum with satisfactory results.