Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Chongqing 400715, People's Republic of China.
Biosens Bioelectron. 2011 Jul 15;26(11):4601-4. doi: 10.1016/j.bios.2011.04.043. Epub 2011 May 6.
A multiple amplification immunoassay was proposed to detect alpha-fetoprotein (AFP), which was based on ferrocenemonocarboxylic-HRP conjugated on Pt nanoparticles as labels for rolling circle amplification (RCA). Firstly, the capture antibody (anti-AFP) was immobilized on glass carbon electrode (GCE) deposited nano-sized gold particles. After a typical immuno-sandwich protocol, primary DNA was immobilized by labeling secondary antibody, which acted as a precursor to initiate RCA. The products of RCA provide large amount of sites to link detection DNAs, which were labeled by signal probes (ferrocenemonocarboxylic) and horseradish peroxidase (HRP). Moreover, the enzymatic amplification signals could be produced by the catalysis of HRP and Pt nanoparticles with the addition of H₂O₂. These lead to multiple amplification signals monitoring by electrochemical instrument and further resulted in high sensitivity of the immunoassay with the detection limit of 1.7 pg/mL.
提出了一种多重免疫分析方法来检测甲胎蛋白（AFP），该方法基于 Pt 纳米粒子上的二茂铁单羧酸-HRP 作为滚环扩增（RCA）的标记物。首先，将捕获抗体（抗 AFP）固定在沉积有纳米金颗粒的玻碳电极（GCE）上。在典型的免疫夹心方案后，通过标记二级抗体将初级 DNA 固定，二级抗体作为引发 RCA 的前体。RCA 的产物提供了大量的连接检测 DNA 的位点，这些 DNA 被信号探针（二茂铁单羧酸）和辣根过氧化物酶（HRP）标记。此外，在添加 H₂O₂的情况下，HRP 和 Pt 纳米粒子的酶促扩增信号可以产生。这导致通过电化学仪器监测多重扩增信号，并进一步导致免疫分析具有高灵敏度，检测限为 1.7 pg/mL。
