基于Pd/COF-LZU1非标记型C-反应蛋白免疫传感器的研制

采用溶剂热法, 通过有机单体合成了一种亚胺键连接的共价有机框架材料(COF-LZU1); 在常温常压条件下, 通过后合成的方法将贵金属钯(Ⅱ)引入到COF材料中, 合成了复合材料Pd/COF-LZU1, 该材料具有优良的催化性能. 利用Pd/COF-LZU1多孔复合材料将C-反应蛋白(CRP)抗体(anti-CRP)固定在玻碳电极表面, 构建了一种非标记型CRP免疫传感器. 当抗体与抗原发生免疫反应时, 形成的免疫复合物会阻碍电化学探针Fe(CN)₆]^4-/3-的电子传递, 降低其响应电流, 从而实现CRP的快速检测. 采用交流阻抗和差示脉冲伏安法(DPV)考察了免疫传感器的电化学特性, 同时考察了测试底液的pH值、 抗原培育时间和抗体固定浓度等实验条件对传感器性能的影响. 在最优的实验条件下, 采用DPV法对CRP进行检测的线性范围为5~180 ng/mL, 检出限为1.66 ng/mL, 线性相关系数为0.992.

Preparation of Label-free C-Reactive Protein Immunosensor Based on the Palladium-coordinated Covalent Organic Frameworks(Pd/COF-LZU1) Material†

A new imine-linked covalent organic framework(COF) material was synthesized using organic monomer via solvothermal methods. Pd(Ⅱ)-coordinated COF, Pd/COF-LZU1, was accordingly synthesized through simple post-treatment at ambient conditions, which showed excellent catalytic activity. Then, a label-free C-reactive protein(CRP) immunosensor was constructed using the Pd/COF-LZUI porous composite material to immobilize anti-CRP on the surface of GCE. When anti-CRP binds with CRP antigen, the formed immuno complex obstruct the electric signal of Fe(CN)₆^4-/3-, which can be used to realize label-free detection of CRP. Electrochemical impedence spectroscopy(EIS) and differential pulse voltammetry(DPV) were employed to characterize the immunosensor. The experimental conditions such as scanning rate, pH value of testing solution, the concentration of anti-CRP and incubation time were also optimized. Under the optimal experimental conditions, the linear range was 5—180 ng/mL, the detection limit was 1.66 ng/mL, with the linear correlation coefficient of 0.992. This immunosensor provides a novel and simple way to detect CRP, and develops the application of the COFs in the electrochemical immunosensor.