State Key Laboratory of Bioelectronics, School of Chemistry and Chemical Engineering, Southeast University, Nanjing, PR China.
Analyst. 2011 Jun 21;136(12):2558-63. doi: 10.1039/c1an15134g. Epub 2011 May 11.
We present a novel immunosensor by using polymerization-assisted signal amplification strategy coupled with electrochemical detection. A sandwich immunoassay process was used to immobilize a polymerization reaction center, the initiator-conjugated polyclonal prostate specific antigen (PSA) or polyclonal carcinoembryonic antigen (CEA) antibodies on the surface of the electrode. Activator generated electron transfer for atom transfer radical polymerization (AGET ATRP) subsequently triggered the local accumulation of glycidyl methacrylate (GMA) monomers. Growth of long chain polymers provided excess epoxy groups for electrochemical tags aminoferrocene (FcNH(2)) coupling, which in turn significantly increased the loading of the signal molecules and enhanced the electrochemical readouts. The detection limit was ∼0.14 pg mL(-1) for PSA and ∼0.10 pg mL(-1) for CEA in PBS buffers. The proposed immunosensor was highly sensitive, selective and has a good match to the clinical electrochemiluminescent method. This suggested that the polymerization-assisted immunosensing strategy could be used as an effective method to significantly enhance signal output of the sandwich immunoassays and acted as a promising platform for the clinical screening of cancer biomarkers.
我们提出了一种新的免疫传感器，采用聚合辅助信号放大策略结合电化学检测。采用三明治免疫分析过程将聚合反应中心、与引发剂偶联的多克隆前列腺特异性抗原 (PSA) 或多克隆癌胚抗原 (CEA) 抗体固定在电极表面。引发剂产生的电子转移引发原子转移自由基聚合 (AGET ATRP)，随后引发甲基丙烯酸缩水甘油酯 (GMA) 单体的局部积累。长链聚合物的生长为电化学标签氨基二茂铁 (FcNH(2)) 偶联提供了多余的环氧基团，这反过来又显著增加了信号分子的负载量并增强了电化学读数。在 PBS 缓冲液中，PSA 的检测限约为 0.14 pg mL(-1)，CEA 的检测限约为 0.10 pg mL(-1)。所提出的免疫传感器具有高灵敏度、选择性，并且与临床电化学发光法非常匹配。这表明聚合辅助免疫传感策略可作为一种有效方法，显著增强三明治免疫分析的信号输出，并为癌症生物标志物的临床筛选提供有前途的平台。
