School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, People's Republic of China.
Biosens Bioelectron. 2011 Oct 15;28(1):112-6. doi: 10.1016/j.bios.2011.07.006. Epub 2011 Jul 18.
A sandwich electrochemical immunosensor for the sensitive determination of alpha fetoprotein (AFP) has been fabricated. Prussian blue modified hydroxyapatite (PB@HAP) was firstly prepared and used as electrochemical label due to the wonderful conductivity and good biocompatibility of HAP. The results proved that the immunosensor fabricated using the label based on PB@HAP loaded with horse radish peroxidase (HRP) and secondary anti-AFP antibody (Ab(2)) (PB@HAP-HRP-Ab(2)) had high sensitivity, and the sensitivity of the label PB@HAP-HRP-Ab(2) was much higher than labels of PB@HAP-Ab(2), PB-HRP-Ab(2) and HAP-HRP-Ab(2). The mixture of graphene sheet (GS) and thionine (TH) was not only used to immobilize anti-AFP antibody (Ab(1)) but also took part in the signal amplification. The amperometric signal increased linearly with AFP concentration in the range of 0.02-8 ng/mL with a low detection limit of 9 pg/mL. The immunosensor had the advantages of high sensitivity, good selectivity and good stability, and was applied to the analysis of AFP in serum sample with satisfactory results. Due to the low-cost and easy synthesis of PB@HAP, the screen-printed electrodes could be used instead of the bare glass carbon electrode in order to achieve mass production. In addition, it had potential application in the detection of other tumor markers.
夹心型电化学免疫传感器用于灵敏测定甲胎蛋白（AFP）。首先制备普鲁士蓝修饰的羟基磷灰石（PB@HAP），因其具有良好的导电性和生物相容性，可用作电化学标记物。结果表明，基于负载辣根过氧化物酶（HRP）和二次抗 AFP 抗体（Ab(2)）的 PB@HAP 标记物（PB@HAP-HRP-Ab(2)）制备的免疫传感器具有高灵敏度，且标记物 PB@HAP-HRP-Ab(2)的灵敏度明显高于 PB@HAP-Ab(2)、PB-HRP-Ab(2)和 HAP-HRP-Ab(2)的灵敏度。石墨烯片（GS）和硫堇（TH）的混合物不仅用于固定抗 AFP 抗体（Ab(1)），还参与信号放大。电化学安培信号随 AFP 浓度在 0.02-8ng/mL 范围内呈线性增加，检测限低至 9pg/mL。该免疫传感器具有灵敏度高、选择性好、稳定性好等优点，用于血清样品中 AFP 的分析，结果令人满意。由于 PB@HAP 成本低、合成简单，可采用丝网印刷电极代替裸玻碳电极，实现批量生产。此外，它在其他肿瘤标志物的检测中具有潜在的应用价值。
