Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education, China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, P. R. China.
Anal Chem. 2022 Apr 12;94(14):5707-5714. doi: 10.1021/acs.analchem.2c00737. Epub 2022 Mar 29.
An electrochemiluminescence (ECL) sensor provides a sensitive and convenient method for early diagnosis of diseases; however, it is still a challenge to develop simple and sensitive sensing platforms based on efficient ECL signals and luminophore groups. Porphyrin-based metal-organic frameworks (MOFs) show great potential in ECL sensing; however, the mechanism and structure-activity relationship, as well as application, are rarely reported. Herein, hydrothermal reactions obtained porphyrin Zr-MOFs (PCN-222) with different specific surface areas, pore sizes, structures, and surface charge states by tuning the reaction time were developed, which served both as the ECL luminophore, coreaction promoter for SO, and a connection in the ECL immunoassay. By progressively controlling the condition of the hydrothermal reaction, PCN-222 with large surface area-abundant micropores can be obtained, which has good conductivity and positively charged surfaces, obtaining excellent ECL performance. The ECL performance and the enhancement mechanism were investigated in detail. Using PCN-222-6h with the best ECL intensity as the immobilization matrix for the aptamer, a highly sensitive and selective assay for thrombin was developed. The decrease of the ECL signal was logarithmically linear with the concentration of thrombin in the range from 50 fg mL to 100 pg mL with a low detection limit of 2.48 fg/mL. This proposed strategy provides a brand new approach for tuning of the structures of MOFs as effective ECL signal probes, thus providing wider possibilities for effective ECL immunoassays in the detection of other biomarkers in diagnosis of diseases.
电化学发光（ECL）传感器为疾病的早期诊断提供了一种灵敏、便捷的方法；然而，基于高效的 ECL 信号和发光团，开发简单、灵敏的传感平台仍然是一个挑战。基于卟啉的金属有机骨架（MOFs）在 ECL 传感中具有很大的应用潜力；然而，其机制和结构-活性关系以及应用很少有报道。在此，通过调节反应时间，水热反应得到了具有不同比表面积、孔径、结构和表面电荷状态的卟啉 Zr-MOFs（PCN-222），它们既可以作为 ECL 发光体，又可以作为 SO 的共反应促进剂，还可以作为 ECL 免疫分析中的连接物。通过逐步控制水热反应的条件，可以得到具有大表面积-丰富微孔的 PCN-222，其具有良好的导电性和带正电荷的表面，从而获得优异的 ECL 性能。详细研究了 ECL 性能和增强机制。使用具有最佳 ECL 强度的 PCN-222-6h 作为适体的固定基质，开发了一种对凝血酶具有高灵敏度和选择性的测定方法。ECL 信号的降低与凝血酶浓度在 50 fg/mL 至 100 pg/mL 的范围内呈对数线性关系，检测限低至 2.48 fg/mL。该策略为 MOFs 的结构调谐提供了一种全新的方法，作为有效的 ECL 信号探针，从而为基于其他生物标志物的疾病诊断中的有效 ECL 免疫分析提供了更广泛的可能性。
