Back to Search
Start Over
Polyethylenimine-Capped CdS Quantum Dots for Sensitive and Selective Detection of Nitrite in Vegetables and Water.
- Source :
-
Journal of agricultural and food chemistry [J Agric Food Chem] 2018 Aug 22; Vol. 66 (33), pp. 8851-8858. Date of Electronic Publication: 2018 Aug 08. - Publication Year :
- 2018
-
Abstract
- In the present work, polyethylenimine-capped CdS quantum dots (PEI-CdS QDs) with bright green fluorescence were synthesized and applied for sensitively and selectively detecting the nitrite in vegetable and water samples. Highly fluorescent and environment-friendly PEI-CdS QDs (quantum yield about 8%) with diameters of ca. 5 nm were easily synthesized by using hyperbranched PEI as functional polymer. Formation of the PEI-CdS QDs was verified by transmission electron microscopy and UV-vis spectroscopy. The fluorescence intensity of the as-synthesized PEI-CdS QDs was enhanced pronouncedly by the increasing amount of PEI and was stable when the pH ranged from 5.0 to 9.0. Our results demonstrated that the fluorescence of the PEI-CdS QDs was effectively quenched by the nitrite in a rather wide linear range of 1.0 × 10 <superscript>-7</superscript> -1.0 × 10 <superscript>-4</superscript> M while efficiently avoiding the interferences from nitrate ions and other commonly coexisting anions of nitrite in the vegetable samples. The detection limit of the present method was lower than the maximum limit of nitrite in drinking water (6.5 × 10 <superscript>-5</superscript> M) ruled by the World Health Organization, which is significant to the application of the method.
Details
- Language :
- English
- ISSN :
- 1520-5118
- Volume :
- 66
- Issue :
- 33
- Database :
- MEDLINE
- Journal :
- Journal of agricultural and food chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 30016094
- Full Text :
- https://doi.org/10.1021/acs.jafc.8b01951