Department of Chemistry, Capital Normal University, Beijing 100048, China.
Biosens Bioelectron. 2013 Dec 15;50:356-61. doi: 10.1016/j.bios.2013.06.054. Epub 2013 Jul 4.
In this work, a sandwich-format electrochemical immunosensor for simultaneous determination of carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP) was fabricated using biofunctional carboxyl graphene nanosheets (CGS) as immunosensing probes, which were fabricated by means of immobilization of toluidine blue (TB) and labeled anti-CEA (Ab2,1), Prussian blue (PB) and anti-AFP (Ab2,2) successively on CGS. The capture anti-CEA (Ab1,1) and anti-AFP (Ab1,2) were immobilized onto the chitosan-Au nanoparticles (CHIT-AuNPs) modified electrode through 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxy succinimide (EDC/NHS). Experimental results revealed that this sandwich-type immunoassay enabled simultaneous detection of CEA and AFP with linear range of 0.5-60 ng mL(-1) for both analytes. The detection limit was 0.1 ng mL(-1) for CEA and 0.05 ng mL(-1) for AFP (S/N=3). The assay results of serum samples with the proposed method were in a good agreement with the reference values from the standard ELISA method. And the negligible cross-reactivity between the two analytes allows it to possess potential promise in clinical diagnosis.
在这项工作中，制备了一种夹心型电化学免疫传感器，用于同时测定癌胚抗原（CEA）和甲胎蛋白（AFP）。该传感器采用生物功能化羧基石墨烯纳米片（CGS）作为免疫传感探针，通过将甲苯胺蓝（TB）和标记的抗 CEA（Ab2,1）、普鲁士蓝（PB）和抗 AFP（Ab2,2）依次固定在 CGS 上来制备。捕获抗 CEA（Ab1,1）和抗 AFP（Ab1,2）通过 1-（3-二甲基氨基丙基）-3-乙基碳二亚胺盐酸盐和 N-羟基琥珀酰亚胺（EDC/NHS）固定在壳聚糖-金纳米粒子（CHIT-AuNPs）修饰电极上。实验结果表明，这种三明治型免疫测定法能够同时检测 CEA 和 AFP，两种分析物的线性范围均为 0.5-60ng mL(-1)。CEA 的检测限为 0.1ng mL(-1)，AFP 的检测限为 0.05ng mL(-1)（S/N=3）。该方法对血清样品的检测结果与标准 ELISA 方法的参考值吻合良好。而且两种分析物之间的交叉反应可以忽略不计，这使其在临床诊断中具有潜在的应用前景。
