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Mu XQ, Wang D, Meng LY, Wang YQ, Chen J. Glutathione-modified graphene quantum dots as fluorescent probes for detecting organophosphorus pesticide residues in Radix Angelica Sinensis. Spectrochim Acta A Mol Biomol Spectrosc 2023; 286:122021. [PMID: 36283209 DOI: 10.1016/j.saa.2022.122021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 10/14/2022] [Accepted: 10/17/2022] [Indexed: 06/16/2023]
Abstract
A novel fluorescent sensor was developed in this study based on glutathione-functionalized graphene quantum dots (GQDs@GSH) to detect organophosphorus pesticide residues in Radix Angelica Sinensis. GQDs@GSH was synthesized by a one-step pyrolysis method with a fluorescence quantum yield as high as 33.9% and its structure was characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. GQDs@GSH exhibited excellent fluorescence property showing strong blue fluorescence under UV irradiation. The fluorescence of GQDs@GSH could be quenched by Fe3+ by electron transfer and the quenched fluorescence could be recovered due to the strong chelating and reducing ability of phytic acid (PA). Under the catalyzation of acetylcholinesterase (AChE) and choline oxidase (ChOx), acetylcholine (ACh) could be decomposed to H2O2, which could further oxidize Fe2+ to Fe3+ thus quenching the fluorescence of GQDs@GSH once again. Coumaphos, a kind of organophosphorus pesticide, could inhibit AChE activity, thus making the quenched fluorescence turn on again. Several parameters influencing the fluorescence response such as Fe3+, PA, ACh and coumaphos concentration, pH value and reaction time were optimized. Based on such a fluorescence "off-on-off-on" ngkmechanism, GQDs@GSH was successfully applied to the detection of coumaphos in Radix Angelica Sinensis. A good linear relationship between the fluorescence intensity and coumaphos concentration was obtained in the range of 0.1-10.0 μmol·L-1. By a standard addition method, the recoveries were measured to be 101.44-117.90% with RSDs lower than 1.98%. The biosensor system is simple, sensitive and accurate. It has a good application prospect in the detection of organophosphorus pesticide residues in traditional Chinese medicine and agricultural products, and also expanded the application scope for glutathione as a highly selective biological molecule.
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Affiliation(s)
- Xi-Qiong Mu
- School of Pharmacy, Gansu University of Chinese Medicine, Lanzhou 730101, China
| | - Dan Wang
- School of Pharmacy, Gansu University of Chinese Medicine, Lanzhou 730101, China
| | - Ling-Yu Meng
- School of Pharmacy, Gansu University of Chinese Medicine, Lanzhou 730101, China
| | - Yin-Quan Wang
- School of Pharmacy, Gansu University of Chinese Medicine, Lanzhou 730101, China; Northwest Collaborative Innovation Center for Traditional Chinese Medicine Co-constructed by Gansu Province & MOE of PRC, Lanzhou 730000, China.
| | - Juan Chen
- School of Pharmacy, Lanzhou University, Lanzhou 730101, China.
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Fu J, Dong H, Zhao Q, Cheng S, Guo Y, Sun X. Fabrication of refreshable aptasensor based on hydrophobic screen-printed carbon electrode interface. Sci Total Environ 2020; 712:136410. [PMID: 32050375 DOI: 10.1016/j.scitotenv.2019.136410] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 12/27/2019] [Accepted: 12/27/2019] [Indexed: 06/10/2023]
Abstract
In order to solve the problem that the sensor cannot be reused due to the passivation of the electrode surface, a refreshable electrochemical aptasensor based on a hydrophobic electrode and a magnetic nanocomposite had been developed. Therein, the hydrophobic electrode was formed by modifying a screen-printed carbon electrode (SPCE) with polydimethylsiloxane (PDMS), which could avoid adsorption of molecules on the electrode surface due to its hydrophobicity. Combined with aptamer (Apt), the synthesized graphene oxide-ferroferric oxide (GO-Fe3O4) was used as a magnetic catcher to capture specific organophosphorus pesticides (OPs), which could be removed to the working area of SPCE with a magnet for electrochemical detection. The performance analysis of hydrophobic electrode showed that the SPCE could be used twice. When the electrochemical signals of Apt/GO-Fe3O4 and OPs/Apt/GO-Fe3O4 were recorded using the same SPCE, the current differences between them were directly related to the concentrations of OPs. Through the contrast test between the spiked vegetable samples and the OPs standard solutions, it was found that the OPs concentrations could be qualitatively evaluated by comparing the current differences. At the same time, the characteristic of collecting target with magnetic catcher was helpful for detecting OPs with a low concentration. Therefore, the refreshable aptasensor provided a huge potential to small molecule target evaluation.
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Affiliation(s)
- Jiayun Fu
- School of Agricultural Engineering and Food Science, Shandong University of Technology, No. 12 Zhangzhou Road, Zibo 255049, China
| | - Haowei Dong
- School of Agricultural Engineering and Food Science, Shandong University of Technology, No. 12 Zhangzhou Road, Zibo 255049, China; Shandong Provincial Engineering Research Center of Vegetable Safety and Quality Traceability, No. 12 Zhangzhou Road, Zibo 255049, China
| | - Qingxue Zhao
- School of Agricultural Engineering and Food Science, Shandong University of Technology, No. 12 Zhangzhou Road, Zibo 255049, China; Zibo City Key Laboratory of Agricultural Product Safety Traceability, China
| | - Shuting Cheng
- School of Agricultural Engineering and Food Science, Shandong University of Technology, No. 12 Zhangzhou Road, Zibo 255049, China; Shandong Provincial Engineering Research Center of Vegetable Safety and Quality Traceability, No. 12 Zhangzhou Road, Zibo 255049, China
| | - Yemin Guo
- School of Agricultural Engineering and Food Science, Shandong University of Technology, No. 12 Zhangzhou Road, Zibo 255049, China; Shandong Provincial Engineering Research Center of Vegetable Safety and Quality Traceability, No. 12 Zhangzhou Road, Zibo 255049, China; Zibo City Key Laboratory of Agricultural Product Safety Traceability, China.
| | - Xia Sun
- School of Agricultural Engineering and Food Science, Shandong University of Technology, No. 12 Zhangzhou Road, Zibo 255049, China; Shandong Provincial Engineering Research Center of Vegetable Safety and Quality Traceability, No. 12 Zhangzhou Road, Zibo 255049, China; Zibo City Key Laboratory of Agricultural Product Safety Traceability, China.
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