Duplex-Specific Nuclease-Triggered Fluorescence Immunoassay Based on Dual-Functionalized AuNP for Acetochlor, Metolachlor, and Propisochlor

Author(s):  
Yonghong Zha ◽  
Yansong Li ◽  
Pan Hu ◽  
Shiying Lu ◽  
Honglin Ren ◽  
...  
2019 ◽  
Vol 13 (1) ◽  
pp. 137-145 ◽  
Author(s):  
Tzonka Godjevargova ◽  
Zlatina Becheva ◽  
Yavor Ivanov ◽  
Andrey Tchorbanov

Objectives: Staphylococcus aureus is a Gram-positive microorganism. S. aureus can grow in various foods and cause food poisoning by secreting enterotoxins. The most common enterotoxins involved in food poisoning are staphylococcal enterotoxin A and staphylococcal enterotoxin B, but Staphylococcal Enterotoxin A (SEA) is predominant. The main types of food contaminated with SEs are meat and meat products, poultry and eggs, milk and dairy products. The aim of this study was to develop a rapid and sensitive fluorescence immunoassay for detection of staphylococcal enterotoxin A in milk. Methods: Monoclonal and polyclonal antibodies for SEA were produced and characterized. Competitive fluorescence immunoassay based on Magnetic Nanoparticles (MNPs) was performed and optimized. MNPs were used as a solid carrier of the antibodies. The first step of the assay was immunoreaction between the immobilized antibody onto MNPs and SEA in milk sample. Then the fluorescein-SEA conjugate was added to the sample. Thus, competitive immunoreaction between MNP-mAb/MNP-pAb with SEA and SEA-FITC was performed. These immuno-complexes were separated by a magnetic separator and the obtained supernatants were analyzed. The fluorescent signal from the excess of conjugated SEA was proportional to the SEA contained in the milk. The assay duration was only 30 min. Results: The fluorescence immunoassays performed with polyclonal antibody had linear ranges from 5 pg/mL to 100 ng/mL SEA in a buffer, and from 50 pg/mL to 50 ng/mL SEA in spiked milk samples. While the same assays performed with monoclonal antibody had linear ranges from 1 pg/mL to 20 ng/mL SEA in buffer, and from 10 pg/mL to 10 ng/mL SEA in spiked milk samples. The detection limits of the developed immunoassays performed in milk were: 48 pg/mL with polyclonal antibody and 9 pg/mL with monoclonal antibody. Conclusion: A rapid and sensitive fluorescence immunoassay based on magnetic nanoparticles with a polyclonal and monoclonal antibody for determination of staphylococcal enterotoxin A in milk was developed.


RSC Advances ◽  
2021 ◽  
Vol 11 (44) ◽  
pp. 27541-27546
Author(s):  
Qingquan Zhang ◽  
Jiajia Li ◽  
Yuting Su ◽  
Xiaoyan Pan ◽  
Hongwei Gai

A contactless and ball-lens assisted sensitivity improvement method was present for the fluorescence or luminescence immunoassay in microchannel.


RSC Advances ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 517-524
Author(s):  
Chuanyong Li ◽  
Wanlin Sun ◽  
Lianrun Huang ◽  
Nana Sun ◽  
Xiude Hua ◽  
...  

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).


2017 ◽  
Vol 5 (4) ◽  
pp. 826-833 ◽  
Author(s):  
Zhenzhen Lin ◽  
Shuzhen Lv ◽  
Kangyao Zhang ◽  
Dianping Tang

This work designs a visual fluorescence immunoassay for carcinoembryonic antigen based on structural and optical transformation of CdTe quantum dots immobilized on paper by cation-exchange reaction.


2021 ◽  
Vol MA2021-02 (7) ◽  
pp. 1896-1896
Author(s):  
Keiko Kojima ◽  
Yoko Iizumi ◽  
Minfang Zhang ◽  
Toshiya Okazaki

2021 ◽  
pp. 113179
Author(s):  
Shaoxiong Zheng ◽  
Renjing Hu ◽  
Xiaomei Yu ◽  
Lingli Chen ◽  
BinrongWang ◽  
...  

2021 ◽  
Author(s):  
Xindong Chen ◽  
Jianfeng Hong ◽  
Han Zhao ◽  
Zhongyi Xiang ◽  
Yuan Qin ◽  
...  

Abstract Background: A rapid and highly sensitive assay for tumor-associated trypsinogen-2 (TAT-2) based on the time-resolved fluorescence immunoassay (TRFIA) detection technique was developed for the determination of serum TAT-2 levels in cancers. Results: The measurement range of TAT-2-TRFIA was 1.53-300 ng/mL. The within-run and between-run coefficients of variation of TAT-2-TRFIA were 4.38% and 7.82%, respectively. The recovery rate of TAT-2-TRFIA was 103.0%. The cross-reaction rates of trypsin and T-cell immunoglobulin mucin 3 were 0.02% and 0.82%, respectively. The TAT-2-positive rates in lung cancer, liver cancer, nasopharyngeal cancer, cholangiocarcinoma, brain cancer, and pancreatic cancer were 45.9%, 50.0%, 45.0%, 64.3%, 50.0%, and 41.7%, respectively, with the areas under ROC curves of 0.788, 0.734, 0.862, 0.720, 0.887, and 0.585, respectively. In patients with lung cancer, the positive rate of the single indicator CEA was 28.4%, which increased to 60.6% after combined use with TAT-2. In patients with cholangiocarcinoma, the positive rate of CA-199 was 35.7%, which increased to 71.4% after combined use with TAT-2. Conclusions: TAT-2 is expected to be used as an auxiliary diagnostic indicator for the combined use of tumor markers to improve the positive rate and accuracy of detection.


2021 ◽  
pp. 131907
Author(s):  
Cai-Xia Liao ◽  
Bao-Zhu Jia ◽  
Hong Wang ◽  
Yuan-Ming Sun ◽  
Xiao-Yan Xu ◽  
...  

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