Development of a multicolor upconversion fluorescence immunoassay for the simultaneous detection of thiamethoxam and dextran by magnetic separation. Issue 1 (23rd December 2020)

• Record Type: Journal Article
• Authors: Li, Chuanyong; Sun, Wanlin; Huang, Lianrun; Sun, Nana; Hua, Xiude; Wang, Minghua; Liu, Fengquan
• Is Part Of: RSC advances. Volume 11:Issue 1(2021)
• Page Start: 517
• Page End: 524
• Publication Date: 2020-12-23
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d0ra07954e
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : The anti-thiamethoxam and anti-dextran monoclonal antibodies were prepared to develop a multicolor upconversion fluorescence immunoassay for the simultaneous determination of thiamethoxam (544 nm) and dextran (477 nm). Abstract : The contents of both pesticide residues and dextran are important parameters for evaluating the quality of sugarcane. In this study, a multicolor upconversion fluorescence immunoassay for the simultaneous detection of thiamethoxam and dextran was established on the basis of magnetic separation. Antigens of thiamethoxam and dextran were coupled to magnetic nanoparticles as the separation elements. Monoclonal antibodies of thiamethoxam (6C7D12) and dextran (3C6F7) were conjugated with the upconversion nanoparticles of NaYF4 :Yb, Er with an emission wavelength at 544 nm and NaYF4 :Yb, Tm with an emission wavelength at 477 nm to prepare the signaling elements, respectively. Due to the difference in the emission wavelength, the signaling elements bound on the separation elements could be detected simultaneously after separation by an external magnetic field. After optimization, the half-maximal inhibitory concentration (IC50 ) values of the immunoassay for thiamethoxam and dextran were 0.46 and 49.33 ng mL −1, respectively. The assay showed no cross-reactivity with the analogs of thiamethoxam and dextran except for clothianidin (8.7%). The average recoveries of thiamethoxam and dextran in sugarcane juice were 82.9–93.3% and 87.5–97.2%, respectively. The results indicated that the immunoassay could meet the requirements for the simultaneous quantitative detection of thiamethoxam and dextran.