Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5398574 | Journal of Luminescence | 2016 | 5 Pages |
Abstract
Graphene quantum dots (GQDs) with particle size of 4.5±1.0 nm were prepared and characterized by transmission electron microscopy, UV-vis absorption spectroscopy and fluorescence spectroscopy. It was found that KMnO4 could oxidize GQDs to produce a relatively intense chemiluminescence (CL) emission. The mechanism of CL generation was investigated based on absorption spectra and CL emission spectra. CL emission was attributed to the radiative recombination of oxidant-injected holes and thermally excited electrons in the GQDs. On the other hand, both KMnO4 and âO2â could react with GQDs to produce GQDsâ+ and GQDsââ. The electron-transfer annihilation of GQDsâ+ and GQDsââ could form excited-state GQDs*, which acted as the final emitter in the system. In order to show the analytic potential of GQDs-KMnO4 CL system, it was applied for the determination of hydroquinone based on its diminishing effect. Under the optimized conditions, the proposed CL system exhibits excellent analytic performance for determination of hydroquinone. Calibration curve in the range of 2.49Ã10â4-9.96Ã10â7 g mLâ1 was linear with the correlation coefficient (r) of 0.9924. The limit of detection was 8.46Ã10â8 g mLâ1, and the relative standard deviation (RSD) was found to be 1.7% for 11 determinations of 4.98Ã10â6 g mLâ1 hydroquinone. The applicability of the method was verified by applying to real tap water, lake water, and waste water samples. The recoveries were in the range of 89.7-97.1% with RSD of 0.9-2.1%. The proposed method has a good linearity, high sensitivity and good repeatability and can be applied for routine determination of hydroquinone in water.
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Ming Su, Peiyun Chen, Yajuan Dong, Hanwen Sun,