Zhang Junjun, Zhang Wenjuan, Guo Jinjin, Wang Junchun, Zhang Yuzhong
College of Chemistry and Materials Science, The Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Key Laboratory of Chem-Biosensing, Anhui Normal University, Wuhu 241000, People's Republic of China.
College of Chemistry and Materials Science, The Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Key Laboratory of Chem-Biosensing, Anhui Normal University, Wuhu 241000, People's Republic of China.
Anal Biochem. 2017 Dec 15;539:1-7. doi: 10.1016/j.ab.2017.09.017. Epub 2017 Sep 28.
In this study, a sandwich-type electrochemical immunosensor for the detection of C-reactive protein (CRP) is described. In design, Copper nanoparticles (Cu NPs) were used for signal tag and hybridization chain reaction (HCR)amplified output signal. The immunosensor fabrication involved three steps: (i) primary antibodies (Ab) were immobilized on the surface of gold nanoparticles (Au NPs); (ii) the sandwich-type structure formation contained "primary antibodies-antigen-secondary antibodies conjugated with primer (Ab-S)"; and (iii) long DNA concatemers intercalating amounts of Cu NPs was linked to the sandwich-type structure via hybridization reaction. Differential pulse voltammetry (DPV) was used to record the response signal of the immunosensor in phosphate-buffered saline (PBS). Under optimal conditions, the anodic peak currents of Cu NPs at the peak potential of about 0.08V(VS.SCE) were linear with the logarithm of CRP concentration in the range of 1.0 fg mL to 100 ng mL with a detection limit of 0.33 fg mL (at signal/noise [S/N] = 3). In addition, the practical application of immunosensor was evaluated by analyzing CRP in real human serum samples, the recoveries obtained were within 95.3%-103.8%, indicating the immunosensor possessed potential application ability for practical disease diagnosis.
在本研究中，描述了一种用于检测C反应蛋白（CRP）的夹心型电化学免疫传感器。在设计上，铜纳米颗粒（Cu NPs）用作信号标签并通过杂交链式反应（HCR）放大输出信号。免疫传感器的制备包括三个步骤：（i）将一抗（Ab）固定在金纳米颗粒（Au NPs）表面；（ii）形成包含“一抗-抗原-与引物偶联的二抗（Ab-S）”的夹心型结构；（iii）通过杂交反应将插入大量Cu NPs的长链DNA串联体连接到夹心型结构上。采用差分脉冲伏安法（DPV）记录免疫传感器在磷酸盐缓冲盐水（PBS）中的响应信号。在最佳条件下，Cu NPs在约0.08V（相对于饱和甘汞电极）的峰电位处的阳极峰电流与CRP浓度的对数在1.0 fg mL至100 ng mL范围内呈线性关系，检测限为0.33 fg mL（信号/噪声[S/N]=3）。此外，通过分析实际人血清样品中的CRP对免疫传感器的实际应用进行了评估，获得的回收率在95.3%-103.8%之间，表明该免疫传感器在实际疾病诊断中具有潜在的应用能力。
