Ultrasensitive determination of 2,4,6-trinitrotoluene by exploiting the strongly enhanced electrochemiluminescence of an assembly between CdSe and graphene quantum dots and its quenching by TNT
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- 作者：Jian-Jun Shi ; Lei-Xia Meng ; Ping Yang
- 关键词：Electrogenerated chemiluminescence ; Amino ; functionalized GQDs ; Peroxodisulfate ; Phosphate buffer ; Glassy carbon electrode ; Electrochemical impedance spectrosocopy ; HRTEM ; FTIR ; Hexacyanoferrate ; Nitroaromatic explosives
- 刊名：Microchimica Acta
- 出版年：2017
- 出版时间：January 2017
- 年：2017
- 卷：184
- 期：1
- 页码：73-80
- 全文大小：
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Nanochemistry; Nanotechnology; Characterization and Evaluation of Materials; Analytical Chemistry; Microengineering;
- 出版者：Springer Vienna
- ISSN：1436-5073
- 卷排序：184
文摘
The authors describe an electrochemiluminescence (ECL) assay for the determination of 2,4,6-trinitrotoluene (TNT) in soil. It is based on the finding that graphene quantum dots (GQDs) strongly enhance the ECL of CdSe quantum dots (CdSe QDs), and ECL is strongly quenched by TNT. In order to assemble the GQDs and CdSe QDs, the latter were functionalized with carboxy groups and then coupled to amino-functionalized GQDs (afGQDs). The resulting CdSe-GQDs conjugation was placed as a thin film on a glassy carbon electrode (GCE). The modified electrode displays an about 8-fold enhanced ECL intensity compared to an GCE with CdSe QDs only, and the onset potential of the ECL reaction is positively shifted by 140 mV. In the presence of TNT, the ECL is quenched due to the formation of the TNT-amine complex. The decrease in ECL intensity is related to the logarithm of the TNT concentration in the range from 0.01 to 100 ppb, with a detection limit as low as 3 ppt. The results of TNT assays in (spiked) soil samples showed recoveries between 99.2 and 105.0 % and relative standard deviations between 3.0 and 8.2 %. This strategy offers a new perspective for developing ECL assays based on the use of semiconductor nanoparticles and graphene-based nanomaterials.