采用抗体包被金磁纳米微粒修饰电极的HIV p24/gp36安培联检芯片

Micro Fluidic Amperometric Immunosensor Chip for HIV p24 andgp36 Antigens Based on Gold Magnetic Nanoensemble Electrode

研制了以聚碳酸酯为基底的双通道安培检测微流控免疫芯片,在其中分别集成了修饰有HIV核心抗原p24/gp36的单克隆一级抗体的纳米金修饰电极,并应用于人血清中p24和gp36抗原的同时分析.检测原理是：基于夹心免疫分析法,在电压驱动下,一次性加入含有p24和gp36样品及HRP酶标记的p24和gp36二级抗体溶液,与电极表面的一级抗体生成夹心免疫复合物;接着在体系中加入H2O2,以方波溶出伏安法检测免疫复合物上HRP催化H2O2的还原电流.在pH为6.2的磷酸缓冲液中,对HIV p24和gp36的检测时间均少于2 min,线性范围为0.5-400μg/L,检测限为0.25μg/L.该芯片集成了加样、分离和检测系统,检测时间短,灵敏度明显高于传统的酶联免疫吸附分析法,可应用于对艾滋病的早期诊断和大范围筛查.

An electrochemical detection biosensor chip is developed for simulately analyzing HIV p24 and gp36 antigens with gold nanoensemble electrode modified by the first monoclonal antibodies of p24 and gp36 antigens and microfluidic control system. The detection principle is based on double-sandwich immunoassay method. The first monoclonal antibodies of p24 and gp36 antigens are fixed on electrode surface, then when the serum containing p24 and gp36 antigens passes through the modified electrode, p24 and gp36 combine with the corresponding antibodies on its surface. Furthermore, the secondary p24 and gp36 antibodies marked by HRP are added to form a sandwich compound. Square wave stripping voltammetry is employed to determine the reduction current by catalyzing H2O2. In pH 6.2 PBS, HIV p24 and gp36 can be detected within 2 minutes with a linear range on calibration curve from 0.5 to 400μg/L and a detection limit of 0.25 μg/L. This biosensor improves the detective sensitivity of p24 and gp36 to 1 A · L· g^-1, and is expected to be chosen for early diagnosis of AIDS and large-scale screening test.