Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Department of Chemistry, Fuzhou University, Fuzhou 350108, People's Republic of China.
Anal Biochem. 2011 Oct 1;417(1):89-96. doi: 10.1016/j.ab.2011.06.001. Epub 2011 Jun 7.
A new electrochemical immunoassay of alpha-fetoprotein (AFP) was developed on an organic-inorganic hybrid nanostructure-functionalized carbon electrode by coupling with magnetic bionanolabels. Multi-walled carbon nanotubes (CNTs), single-stranded DNA, thionine and AFP were utilized for the construction of the immunosensor, while the core-shell Fe(3)O(4)-silver nanocomposites were employed for the label of horseradish peroxidase-anti-AFP conjugates (HRP-anti-AFP-AgFe). Electrochemical measurement toward AFP was carried out by using magnetic bionanolabels as traces and H(2)O(2) as enzyme substrate with a competitive-type immunoassay mode. Experimental results indicated that the immunosensors with carbon nanotubes and DNA exhibited better electrochemical responses than those of without carbon nanotubes or DNA. Under optimal conditions, the electrochemical immunosensor by using HRP-anti-AFP-AgFe as signal antibodies exhibited a linear range of 0.001-200 ng mL(-1) AFP with a low detection limit of 0.5 pg mL(-1) at 3s(B). Both intra- and inter-assay coefficients of variation were 7.3%, 9.4%, 8.7% and 10.2%, 7.8%, 9.4% toward 0.01, 30, 120 ng mL(-1) AFP, respectively. The specificity and stability of the electrochemical immunoassay were acceptable. In addition, the methodology was validated for 12 clinical serum specimens including 9 positive specimens and 3 normal specimens, receiving a good correlation with the results obtained from the referenced electrochemiluminescence assay.
一种新的电化学免疫分析甲胎蛋白（ AFP ）开发了一种有机 - 无机杂化纳米结构功能化碳电极耦合与磁性生物纳米标签。多壁碳纳米管（ CNTs ），单链 DNA ，硫堇和 AFP 被用于构建免疫传感器，而核壳 Fe （ 3 ） O （ 4 ） - 银纳米复合材料被用于辣根过氧化物酶 - 抗 AFP 结合物（ HRP - 抗 AFP - AgFe ）的标记。通过使用磁性生物纳米标签作为示踪物和 H （ 2 ） O （ 2 ）作为酶底物，以竞争型免疫分析模式进行 AFP 的电化学测量。实验结果表明，具有碳纳米管和 DNA 的免疫传感器比没有碳纳米管或 DNA 的免疫传感器具有更好的电化学响应。在最佳条件下，使用 HRP - 抗 AFP - AgFe 作为信号抗体的电化学免疫传感器对 AFP 表现出 0.001-200ngml （ -1 ）的线性范围，检测限低至 3s （ B ）时为 0.5pgml （ -1 ）。对 0.01 、 30 、 120ngml （ -1 ） AFP 的内和间分析变异系数分别为 7.3% 、 9.4% 、 8.7% 和 10.2% 、 7.8% 、 9.4% 。电化学免疫分析的特异性和稳定性是可以接受的。此外，该方法还验证了 12 份临床血清标本，包括 9 份阳性标本和 3 份正常标本，与参考电化学发光法的结果具有良好的相关性。
