Han Xiangning, Liu Chang, Guo Xinping, Sui Jianxin, Lin Hong, Chen Xiangfeng, Cao Limin
College of Food Science and Engineering, Ocean University of China, 5 Yushan Rd, Qingdao, China.
Shandong Analysis and Test Center, Qilu University of Technology, 19 Keyuan Rd, Jinan, China.
Heliyon. 2023 Jun 4;9(6):e16821. doi: 10.1016/j.heliyon.2023.e16821. eCollection 2023 Jun.
There is now increasing demand to improve the sensitivity of various immunoassays for fluoroquinolones (FQs) and other food hazards. In this study, different coating antigens were prepared by adjusting the content of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) to explore its influence on the immunoassay sensitivity of FQs. The results indicated that, unlike traditional assumptions, a reasonable EDC dosage should be addressed to reach the best analytical efficiency, and excessive EDC could enhance the hapten-carrier conjugation but significantly reduce the detection sensitivity. For the FQs investigated, the hapten:EDC:BSA proportion of 20:2.5:50 (Mole ratio:74:34:1) seemed the best for preparation of coating antigens, and the sensitivity could be improved more than 1000 times both for indirect competitive enzyme linked immunosorbent assay ELISA (ic-ELISA) and gold immunochromatography assay (GICA) due to two key factors including coupling-ratios and amide bond groups. Such an improved efficiency was also validated well with different food samples, which indicated the reasonable optimization of EDC in coating antigen synthesis may be widely used as a new, simple and more effective strategy to improve the immunoassay for low molecular targets in medical, environment and food detection filed.
目前，提高各种氟喹诺酮类药物（FQs）及其他食品危害物免疫分析灵敏度的需求日益增加。在本研究中，通过调整1-（3-二甲氨基丙基）-3-乙基碳二亚胺盐酸盐（EDC）的含量制备不同的包被抗原，以探讨其对FQs免疫分析灵敏度的影响。结果表明，与传统假设不同，应确定合理的EDC用量以达到最佳分析效率，过量的EDC可增强半抗原-载体偶联，但会显著降低检测灵敏度。对于所研究的FQs，半抗原:EDC:牛血清白蛋白（BSA）比例为20:2.5:50（摩尔比:74:34:1）似乎是制备包被抗原的最佳比例，由于偶联率和酰胺键基团这两个关键因素，间接竞争酶联免疫吸附测定（ic-ELISA）和金免疫层析测定（GICA）的灵敏度均可提高1000倍以上。不同食品样品也很好地验证了这种提高的效率，这表明在包被抗原合成中合理优化EDC可作为一种新的、简单且更有效的策略，广泛应用于医学、环境和食品检测领域中低分子靶标的免疫分析。
