Zhang Qidi, Zou Ming, Wang Wanyu, Li Jinyan, Liang Xiao
College of Veterinary Medicine, Qingdao Agricultural University, No. 700 Changcheng Road, Qingdao 266109, China.
Basic Medical College, Qingdao University, No. 308 Ningxia Road, Qingdao 266071, China.
Foods. 2021 Aug 6;10(8):1822. doi: 10.3390/foods10081822.
The compound, 4,4'-dinitrocarbanilide (DNC), is the marker residue of concern in edible tissues of broilers fed with diets containing anticoccidial nicarbazin (NIC). In this study, 25 fluorescein-labeled DNC derivatives (tracers) are synthesized and characterized to develop a rapid fluorescence polarization immunoassay (FPIA) for the detection of DNC in chickens using DNC monoclonal antibodies (mAbs). The effect of the tracer structure on the sensitivity of the FPIA is investigated. Our results show that after optimization, the half maximal inhibitory concentrations (IC) and limit of detection (LOD) of the FPIA in the buffer are 28.3 and 5.7 ng mL, respectively. No significant cross-reactivity (CR < 0.89%) with 15 DNC analogues is observed. The developed FPIA is validated for DNC detection in spiked chicken homogenates, and recoveries ranged from 74.2 to 85.8%, with coefficients of variation <8.6%. Moreover, the total time needed for the detection procedure of the FPIA, including sample pretreatment, is <40 min, which has not been achieved in any other immunoassays for DNC from literature. Our results demonstrate that the FPIA developed here is a simple, sensitive, specific, and reproducible screening method for DNC residues in chickens.
化合物4,4'-二硝基碳酰苯胺（DNC）是饲喂含抗球虫药尼卡巴嗪（NIC）日粮的肉鸡可食组织中关注的残留标志物。在本研究中，合成并表征了25种荧光素标记的DNC衍生物（示踪剂），以开发一种使用DNC单克隆抗体（mAb）检测鸡体内DNC的快速荧光偏振免疫分析（FPIA）方法。研究了示踪剂结构对FPIA灵敏度的影响。我们的结果表明，优化后，FPIA在缓冲液中的半数抑制浓度（IC）和检测限（LOD）分别为28.3和5.7 ng/mL。未观察到与15种DNC类似物有明显的交叉反应（CR < 0.89%）。所开发的FPIA在加标鸡匀浆中检测DNC的方法得到验证，回收率在74.2%至85.8%之间，变异系数<8.6%。此外，FPIA检测程序（包括样品预处理）所需的总时间<40分钟，这是文献中任何其他DNC免疫分析方法都未达到的。我们的结果表明，这里开发的FPIA是一种用于检测鸡体内DNC残留的简单、灵敏、特异且可重复的筛选方法。
