Rapid and selective"turn-on"fluorescent detection of fluoride ion in aqueous solution using nitrogen-doped carbon quantum dots
Nitrogen-doped carbon quantum dots(NCDs)were synthesized by a facile hydrothermal method using citric acid as the carbon source and urea as the nitrogen source,and were applied as a novel"turn-on"fluorescent probe for the detection of fluoride ions(F-)in water.The structural and spectroscopic properties of the NCDs were characterized by transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),infrared spectroscopy(FT-IR),ultraviolet-visible spectroscopy(UV-vis),and fluorescence spectroscopy.The sensitivity,stability and selectivity of the NCDs probe to detect F-as well as its applicability in natural water samples were investigated.NCDs showed blue fluorescence emission under ultraviolet light irradiation,and had a high fluorescence quantum yield of 41％.The NCDs can react with aluminium ions(Al3+)via the surface oxygen-containing groups,which would quench the fluorescence emission of NCDs.Due to the strong coordination affinity,F-can compete with NCDs for Al3+and thus recover the fluorescence of NCDs.There existed a good linear relationship between the recovery ratio of NCDs fluorescence and F-concentration(R2=0.995),suggesting the possibility of NCDs in F-quantification.The NCDs-based fluorescence method for F-detection exhibited a short response time(approximately 1.0 min),wide linear range(20-300 μmol·L-1),low detection limit(0.65 μmol·L-1),good selectivity(influences of common ions below 5％),and satisfactory stability in environmentally relevant pH range(pH 6.0-9.0).Finally,the proposed method was successfully applied in the analysis of F-in real water samples with high recoveries(88.2％-105.0％)and precision(relative standard deviations lower than 3.0％).
NETL
NSTL
万方数据
