Chen Xuwei, Zheng Xuan, Yu Xiangyong, Li Xiaoqin, Lin Youxiu, Lin Huizi, Ye Shuai, Huang Xinyu, Tang Dianping, Lai Wenqiang
Key Laboratory of Modern Analytical Science and Separation Technology, College of Chemistry, Chemical Engineering and Environment, Minnan Normal University, Zhangzhou, 363000, People's Republic of China.
Key Laboratory of Modern Analytical Science and Separation Technology, College of Chemistry, Chemical Engineering and Environment, Minnan Normal University, Zhangzhou, 363000, People's Republic of China.
Talanta. 2023 Jun 1;258:124414. doi: 10.1016/j.talanta.2023.124414. Epub 2023 Mar 5.
This work for the first time reports on a simple and rapid colorimetric immunoassay with rapid coordination of ascorbic acid 2-phosphate (AAP) and iron (III) for determination of carcinoembryonic antigen (CEA, used as a model) by using FeO nanoparticle based-chromogenic substrate system. The signal was produced rapidly (1 min) from the coordination of AAP and iron (III) with color development of colorless to brown. TD-DFT calculation methods were employed to simulate the UV-Vis spectra of AAP-Fe and AAP-Fe complexes. Moreover, FeO nanoparticle could be dissolved with the aid of acid, thereby releasing free iron (III). Herein, a sandwich-type immunoassay was established based on FeO nanoparticle as labels. As target CEA concentration increased, the number of FeO labelled-antibodies (bound specifically) increased, resulting in loading more FeO nanoparticle on platform. The absorbance increased as the number of free iron (III), derived from FeO nanoparticle, increased. So, the absorbance of reaction solution is positively correlated with antigen concentration. Under optimal conditions, the current results showed good performance for CEA detection in the range 0.02-10.0 ng/mL with a detection limit of 11 pg/mL. Moreover, the repeatability, stability, and selectivity of the colorimetric immunoassay were also acceptable.
本研究首次报道了一种简单快速的比色免疫分析法，该方法利用基于FeO纳米颗粒的显色底物体系，通过抗坏血酸2 - 磷酸酯（AAP）与铁（III）的快速配位反应来测定癌胚抗原（CEA，用作模型）。AAP与铁（III）配位反应迅速（1分钟），溶液由无色变为棕色产生信号。采用TD - DFT计算方法模拟AAP - Fe和AAP - Fe配合物的紫外 - 可见光谱。此外，FeO纳米颗粒可在酸的作用下溶解，从而释放出游离的铁（III）。在此，基于FeO纳米颗粒作为标记物建立了夹心型免疫分析法。随着目标CEA浓度的增加，FeO标记抗体（特异性结合）的数量增加，导致平台上负载更多的FeO纳米颗粒。随着来自FeO纳米颗粒的游离铁（III）数量增加，吸光度增大。因此，反应溶液的吸光度与抗原浓度呈正相关。在最佳条件下，当前结果表明该方法在0.02 - 10.0 ng/mL范围内对CEA检测具有良好性能，检测限为11 pg/mL。此外，该比色免疫分析法的重复性、稳定性和选择性也令人满意。
