Sonochemical Synthesis of Cyclodextrin-Coated Quantum Dots for Optical Detection of Pollutant Phenols in Water
Haibing Li
Cuiping Han
10.1021/cm8009176.s002
https://acs.figshare.com/articles/journal_contribution/Sonochemical_Synthesis_of_Cyclodextrin_Coated_Quantum_Dots_for_Optical_Detection_of_Pollutant_Phenols_in_Water/2907784
A simple, rapid sonochemical procedure for the preparation of highly fluorescent and water-soluble CdSe/ZnS quantum dots (QDs) using α-, β-, and γ-cyclodextrin (CD) as surface-coating agents is reported. The water-soluble QDs were characterized by luminescence spectroscopy, UV−vis spectroscopy, FT-IR spectroscopy, NMR spectroscopy, and transmission electron microscopy (TEM). The quantum yields (QYs) of α-CD-QDs, β-CD-QDs, and γ-CD-QDs in water were about 45, 39, and 27%, respectively. The <i>n</i>-CD-QDs allow highly sensitive determination of phenols by changing CD coating via fluorescence intensity quenching. The α-CD-QDs and β-CD-QDs are sensitive toward <i>p</i>-nitrophenol and 1-naphthol, respectively. Under optimal conditions, the relative fluorescence intensities of α-CD/CdSe/ZnS QDs and β-CD/CdSe/ZnS QDs both decreased linearly with increasing <i>p</i>-nitrophenol and 1-naphthol in the concentration range of 0.01−100 μM, with the corresponding detection limits (3σ) of 7.92 × 10<sup>−9</sup> and 4.83 × 10<sup>−9</sup> M, respectively. However, the sensitivity of <i>n</i>-CD-QDs toward other phenols, including <i>o</i>-nitrophenol, <i>m</i>-nitrophenol, 2-naphthol, <i>o</i>-cresol, <i>m</i>-cresol and <i>p</i>-cresol, are negligible. It is found that <i>p</i>-nitrophenol and 1-naphthol can quench the luminescence of α-CD-QDs and β-CD-QDs in a concentration-dependent manner that is best described by a Stern−Volmer-type equation. The possible underlying mechanism is discussed.
2008-10-14 00:00:00
CD coating
NMR spectroscopy
Optical Detection
luminescence spectroscopy
naphthol
UV
TEM
quantum yields
Pollutant Phenols
sonochemical procedure
transmission electron microscopy
fluorescence intensities
fluorescence intensity quenching
concentration range
phenol
QY
Sonochemical Synthesis
QD