Li Xiaojian, Lu Yujia, Feng Jinhui, Jia Liping, Shang Lei, Ma Rongna, Zhang Wei, Wang Huaisheng
School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, 252000, Shandong, China.
Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, School of Chemistry and Chemical Engineering, Linyi University, Linyi, 276000, Shandong, China.
Mikrochim Acta. 2025 May 23;192(6):369. doi: 10.1007/s00604-025-07204-y.
Ruthenium (Ru) nanoparticles were immobilized on the g-CN surface (Ru-g-CN), attaining lower potential electrochemiluminescence (ECL) emission of g-CN and yielding an exceptional ECL signal. This enhancement was attributed to the formation of a Schottky barrier between Ru nanoparticles and g-CN, which mitigated electrode passivation and provides catalytically active sites that facilitated the generation of SO electrogenerated by the coreactant KSO. At the same potential, luminol undergone an ECL reaction with the SO to generate luminol radicals, which can subsequently enter a competitive reaction with Ru-g-CN, significantly reducing the ECL intensity of Ru-g-CN. NH-MIL-101(Fe) was utilized to couple with luminol (NH-MIL-101(Fe)@Luminol), which can further enhance the quenching efficiency. This design not only efficiently quench the ECL intensity of Ru-g-CN, but it could also be utilized for immobilizing the secondary antibody of heart-type fatty acid binding protein (H-FABP) which is a biomarker for acute myocardial infarction. By undergoing an immune reaction with the antigen H-FABP, the labels (Ab-NH-MIL-101(Fe)@Luminol) were immobilized onto the electrode surface, and their quantity on the electrode surface changes accordingly with variations in antigen concentrations. Based on this principle, a competitive ECL immunosensor was constructed for detecting H-FABP. The range of detection extended from 5.0 fg mL to 50 ng mL, and a low detection limit of 2.43 fg mL (S/N = 3) were attained.
钌（Ru）纳米颗粒固定在g-CN表面（Ru-g-CN），实现了g-CN较低电位的电化学发光（ECL）发射，并产生了优异的ECL信号。这种增强归因于Ru纳米颗粒与g-CN之间形成了肖特基势垒，该势垒减轻了电极钝化，并提供了催化活性位点，促进了由共反应物KSO产生的SO的生成。在相同电位下，鲁米诺与SO发生ECL反应生成鲁米诺自由基，随后鲁米诺自由基可与Ru-g-CN发生竞争反应，显著降低Ru-g-CN的ECL强度。利用NH-MIL-101(Fe)与鲁米诺偶联（NH-MIL-101(Fe)@鲁米诺），可进一步提高猝灭效率。这种设计不仅能有效猝灭Ru-g-CN的ECL强度，还可用于固定急性心肌梗死生物标志物心脏型脂肪酸结合蛋白（H-FABP）的二抗。通过与抗原H-FABP发生免疫反应，将标记物（Ab-NH-MIL-101(Fe)@鲁米诺）固定在电极表面，其在电极表面的数量会随抗原浓度的变化而相应改变。基于这一原理，构建了一种用于检测H-FABP的竞争性ECL免疫传感器。检测范围从5.0 fg mL扩展到50 ng mL，实现了2.43 fg mL（S/N = 3）的低检测限。
