一种快速高选择性检测痕量癌胚抗原的共振散射光谱法

用10 nm的金纳米粒子标记单克隆癌胚抗原抗体制备了检测癌胚抗原（CEA）的共振散射光谱探针（Au-CEAAb）。在pH 6.8 的Na2HPO4- NaH2PO4缓冲溶液中及聚乙二醇-6000存在下， CEA与Au-CEAAb发生免疫反应聚集形成疏水性的、平均粒径为227.0 nm的免疫复合物微粒，并在321 nm、581 nm产生2个共振散射峰。随着癌胚抗原（CEA）浓度的增大，581 nm处的共振散射强度I581nm线性增加，其增加值△I581nm与CEA浓度在1.0～50.0 ng·mL-1范围内呈良好的线性关系，相应的回归方程、相关系数、检出限(3σ)分别为ΔI581nm=1.63 C +5.6、0.9940、0.52 ng·mL-1。该法简便、快速、灵敏且选择性好，用于检测人血清中癌胚抗原（CEA），结果满意。

A Rapid and Highly Selective Resonance Scattering Spectral Assay for Trace Carcinoembryonic Antigen

Gold nanoparticles, in size of 10 nm, were used to label monoclonal carcinoembryonic antigen antibody (CEAAb) to obtain an immunonanogold resonance scattering (RS) spectral probe (AuCEAAb) for the measurement of trace carcinoembryonic antigen (CEA). In pH 6.8 Na₂HPO₄‐NaH₂PO₄ buffer solution and the presence of polyethylene glycol (PEG)‐6000, the AuCEAAb combined with CEA to form the nanogold‐labeled immunocomplex clusters in average size of 227 nm, which exhibited two scattering peaks at about 320 and 581 nm. The enhanced RS intensity at 581 nm (ΔI_{581 nm}) is proportional to CEA concentration in the range of 1.0–50.0 ng/mL, with a detection limit (DL) of 0.52 ng/mL. The immunonanogold RS assay was utilized to determine CEA in serum samples with high sensitivity, good selectivity and simplicity.