Carbon Nanoparticle Enhanced Immunoelectrochemical Detection for Protein Tumor Marker with Cadmium Sulfide Biotracers
Carbon Nanoparticle Enhanced Immunoelectrochemical Detection for Protein Tumor Marker with Cadmium Sulfide Biotracers
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DOI：
10.1021/ac801832h
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发表时间：
2009-02-15
影响因子：
7.4
通讯作者：
Chou, Pi-Tai
中科院分区：
文献类型：
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作者：
Ho, Ja-an Annie;Lin, Yeh-Chun;Chou, Pi-Tai
我们开发了一种灵敏的电化学免疫分析系统，用于检测蛋白质肿瘤标志物癌胚抗原（CEA），该系统基于碳纳米颗粒(CNP)/聚（乙烯亚胺）（PEI）修饰的丝网印刷石墨电极（CNP-PEI/SPGE）覆盖抗CEA抗体。信号放大策略-使用CdS纳米晶体作为生物示踪剂和CNPs来增强电子转移-提高了CEA的灵敏度和检测极限，这表明该系统有望发展成为即时护理或一次性家庭护理自我诊断工具。该生物传感器基于夹心复合物免疫分析法，由CNP-PEI/SPGE上的抗CEA抗体（α CEA）、CEA样品和α CEA敏化的CdS纳米晶体量子点（α CEA-CdS QD）的连续层组装而成。我们使用方波阳极溶出伏安法（SWASV）来放大从溶解的aCEA-CdS量子点得到的信号电流响应。CEA浓度在0.032 ~ 10 ng/mL范围内呈线性关系，检出限为32 pg/mL（相当于5 μ L样品的160 fg）（以空白样品的平均值加空白样品的3倍标准差估计）。该方法具有较好的准确性和敏感性，可作为测定尿CEA的一种手段，作为早期检测尿路上皮癌的一种较好的标志物。
We have developed a sensitive electrochemical immunoassay system for the detection of a protein tumor marker, carcinoembryonic antigen (CEA), that is based on a carbon nanoparticle (CNP)/poly(ethylene imine) (PEI)-modified screen-printed graphite electrode (CNP-PEI/SPGE) covered with anti-CEA antibodies. The signal amplification strategy-using CdS nanocrystals as biotracers and CNPs to enhance electron transfer-improves the sensitivity and detection limit for CEA, suggesting that this system holds promise for development into a point-of-care or disposable home-care self-diagnostic tool. This biosensor is based on a sandwich complex immunoassay, which we assembled from sequential layers of the anti-CEA antibody (alpha CEA) on CNP-PEI/SPGE, the CEA sample, and the CdS nanocrystal quantum dots (QDs) sensitized with alpha CEA (alpha CEA-CdS QD). We used square wave anodic stripping voltammetry (SWASV) to amplify the signal current response obtained from the dissolved aCEA-CdS QDs. The calibration curve for CEA concentration was linear in the range of 0.032-10 ng/mL, the detection limit (estimated as the mean of the blank sample plus three times the standard deviation obtained on the blank sample) was 32 pg/mL (equivalent to 160 fg in a 5 mu L sample). This method is suitably precise and sensitive to function as a means of determining urinary CEA, which is a better marker than serum CEA for the early detection of urothelial carcinoma.