Liu Fangming, Zhang Honglian, Wu Zhenhua, Dong Haidao, Zhou Lin, Yang Dawei, Ge Yuqing, Jia Chunping, Liu Huiying, Jin Qinghui, Zhao Jianlong, Zhang Qiqing, Mao Hongju
Institute of Biomedical and Pharmaceutical Technology, Fuzhou University, Fuzhou 350002, PR China; State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, PR China.
State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, PR China.
Talanta. 2016 Dec 1;161:205-210. doi: 10.1016/j.talanta.2016.08.048. Epub 2016 Aug 16.
Carcinoembryonic antigen (CEA) is an important biomarker in cancer diagnosis. Here, we present an efficient, selective lateral-flow immunoassay (LFIA) based on magnetic nanoparticles (MNPs) for in situ sensitive and accurate point-of-care detection of CEA. Signal amplification mechanism involved linking of detection MNPs with signal MNPs through biotin-modified single-stranded DNA (ssDNA) and streptavidin. To verify the effectiveness of this modified LFIA system, the sensitivity and specificity were evaluated. Sensitivity evaluation showed a broad detection range of 0.25-1000ng/ml for CEA protein by the modified LFIA, and the limit of detection (LOD) of the modified LFIA was 0.25ng/ml, thus producing significant increase in detection threshold compared with the traditional LFIA. The modified LFIA could selectively recognize CEA in presence of several interfering proteins. In addition, this newly developed assay was applied for quantitative detection of CEA in human serum specimens collected from 10 randomly selected patients. The modified LFIA system detected minimum 0.27ng/ml of CEA concentration in serum samples. The results were consistent with the clinical data obtained using commercial electrochemiluminescence immunoassay (ECLIA) (p<0.01). In conclusion, the MNPs based LFIA system not only demonstrated enhanced signal to noise ratio, it also detected CEA with higher sensitivity and selectivity, and thus has great potential to be commercially applied as a sensitive tumor marker filtration system.
癌胚抗原（CEA）是癌症诊断中的一种重要生物标志物。在此，我们展示了一种基于磁性纳米颗粒（MNPs）的高效、选择性侧向流动免疫分析（LFIA），用于原位灵敏且准确地即时检测CEA。信号放大机制涉及通过生物素修饰的单链DNA（ssDNA）和链霉亲和素将检测MNPs与信号MNPs连接起来。为验证这种改进的LFIA系统的有效性，对其灵敏度和特异性进行了评估。灵敏度评估显示，改进后的LFIA对CEA蛋白的检测范围为0.25 - 1000ng/ml，检测限（LOD）为0.25ng/ml，因此与传统LFIA相比，检测阈值有显著提高。改进后的LFIA在存在几种干扰蛋白的情况下能够选择性地识别CEA。此外，这种新开发的检测方法应用于对从10名随机选择的患者收集的人血清样本中的CEA进行定量检测。改进后的LFIA系统在血清样本中检测到的CEA浓度最低为0.27ng/ml。结果与使用商业电化学发光免疫分析（ECLIA）获得的临床数据一致（p<0.01）。总之，基于MNPs的LFIA系统不仅展示了增强的信噪比，还以更高的灵敏度和选择性检测CEA，因此作为一种灵敏的肿瘤标志物筛选系统具有巨大的商业应用潜力。
