Fluorescence sensing of nitric oxide in aqueous solution by triethanolamine-modified CdSe quantum dots.
The water-soluble luminescent CdSe quantum dots were prepared by ligand exchange with triethanolamine (TEA). Oxygen can reversibly enhance the fluorescence of the synthesized quantum dots (TEA-CdSe-QDs) in aqueous solution. Nitric oxide radical (NO) can react easily with dissolved oxygen in water and was found to have a significant quenching effect on the fluorescence of the TEA-CdSe-QDs. The fluorescence responses were concentration-dependent and can be well described by the typical Stern-Volmer equation. A good linear relationship (R(2 )= 0.9963) was observed over the range 5.92 x 10(-7 )to 1.85 x 10(-5) mol/L nitric oxide. Above this concentration was a second linear region ranging from 2.12 x 10(-5) to 1.12 x 10(-4 )mol/L NO with a gentler slope. The detection limit, calculated following the 3sigma IUPAC criteria, was 3.02 x 10(-7 )mol/L. The interference effect of some common interferents such as nitrite (NO2 (-)), nitrate (NO(3) (-)), glucose and l-ascorbic acid on the detection of NO was negligible for the proposed system, demonstrating the potential utility of this probe for the detection of NO in biological systems. The possible mechanism was also discussed.
Yan
Xiao Qing
XQ
School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, People's Republic of China.
Shang
Zhuo Bin
ZB
Zhang
Zhao
Z
Wang
Yu
Y
Jin
Wei Jun
WJ
D019187:Cadmium Compounds / Q000737:chemistry*; D004983:Ethanolamines / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009569:Nitric Oxide / Q000032:analysis* / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry*; D012995:Solubility; D014867:Water / Q000737:chemistry*
D019187:Cadmium Compounds; D004983:Ethanolamines; D005456:Fluorescent Dyes; D018036:Selenium Compounds; D014867:Water; D009569:Nitric Oxide; C009546:triethanolamine; C058667:cadmium selenide; D010100:Oxygen