College of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650092, PR China.
Clin Chim Acta. 2011 Mar 18;412(7-8):550-5. doi: 10.1016/j.cca.2010.12.004. Epub 2010 Dec 10.
Human chorionic gonadotrophin (hCG) is a secretion of the placenta during pregnancy and gestational trophoblastic diseases. It increases as a consequence of abnormal placental invasion and placental immaturity. So, it is an important diagnostic marker of pregnancy and many diseases such as the hydatidiform mole, the choriocarcinoma, the orchic teratoma, etc.
A novel amperometric immunosensor for determination of hCG was constructed by immobilizing hCG antibody on the Pt-Au alloy nanotube array which was produced by electrodepositing strategy using nanopore polycarbonate (PC) membrane at -0.35 V. The vertically aligned Pt -Au alloy nanotube can be considered as an electrode and therefore each of the electrodes is similar to the nanoelectrode. The determination of hCG antigen was based on its obstruction to the electrocatalytic reduction of H(2)O(2) by Pt-Au alloys after binding to the surface of electrode through immunoreactions.
The electrochemical behaviors were characterized with electrochemical impedance, cyclic voltammetry and chronoamperometry. Under the optimum condition, the current response of the immunosensor is in linear relationship with concentration of hCG ranging from 25 to 400 mIU/ml with a detection limit of 12 mIU/ml. Satisfactory results were obtained for determination of hCG in serum samples.
This sensor displayed high selectivity, long-term stability and simplicity.
人绒毛膜促性腺激素（hCG）是妊娠期间胎盘的一种分泌物，与妊娠滋养细胞疾病有关。它是由于异常的胎盘侵袭和胎盘不成熟而增加的。因此，它是妊娠和许多疾病的重要诊断标志物，如葡萄胎、绒毛膜癌、睾丸畸胎瘤等。
通过在纳米孔聚碳酸酯（PC）膜上在-0.35V 下使用电沉积策略在 Pt-Au 合金纳米管阵列上固定 hCG 抗体，构建了用于测定 hCG 的新型电流型免疫传感器。垂直排列的 Pt-Au 合金纳米管可以被视为电极，因此每个电极都类似于纳米电极。hCG 抗原的测定是基于其与电极表面通过免疫反应结合后，对 Pt-Au 合金电催化还原 H（2）O（2）的阻碍作用。
用电化学阻抗、循环伏安法和计时安培法对电化学行为进行了表征。在最佳条件下，免疫传感器的电流响应与 hCG 浓度在 25 至 400 mIU/ml 范围内呈线性关系，检测限为 12 mIU/ml。对血清样品中 hCG 的测定取得了满意的结果。
该传感器具有高选择性、长期稳定性和简单性。
