Heart failure (HF) is a burgeoning public health problem trigged by a heart circulation disorder. N-terminal pro-B-type natriuretic peptide (NT-proBNP) has been acknowledged as a prognostic biomarker for cardiac disease. Herein, a sandwich-type electrochemiluminescence (ECL) immunosensor was introduced for sensitive detection of NT-proBNP. Gold nanoparticle modified graphene oxide-Ru(bpy)₃²⁺/Ag₂C₂O₄ was used as a luminophore and a desirable platform for immobilization of the captured antibodies. The more stable immobilization of plentiful Ru(bpy)₃²⁺ could be implemented by direct covalent bonding chelation with Ag₂C₂O₄. More importantly, significant quenching can be achieved by introducing polydopamine (PDA) coated Fe₃O₄ onto the electrode via sandwich immunoreactions. The quenching mechanism mainly showed that the excited states of Ru(bpy)₃²⁺ could be annihilated by quinone units in PDA via energy transfer. The ECL quenching efficiency was logarithmically related to the concentration of the NT-proBNP in the range from 0.0005 ng/mL to 100.0 ng/mL with a detection limit of 0.28 pg/mL. Furthermore, this specific immunosensor presented good stability and repeatability as well as selectivity, which offers a guiding significance in both fundamental and clinical diagnosis of NT-proBNP.

中文翻译：

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Fe ₃ O ₄ @PDA与草酸银配位的Ru（bpy）₃ ²⁺高效猝灭策略的三明治型电化学发光传感器检测NT-proBNP

心力衰竭（HF）是由心脏循环疾病引发的新兴公共健康问题。N端前B型利钠肽（NT-proBNP）已被公认为是心脏病的预后生物标志物。在此，引入了夹心型电化学发光（ECL）免疫传感器，用于敏感地检测NT-proBNP。金纳米粒子修饰的氧化石墨烯-Ru（bpy）₃ ²⁺ / Ag ₂ C ₂ O ₄用作发光体和固定捕获抗体的理想平台。大量Ru（bpy）₃ ²⁺的更稳定固定可以通过与Ag ₂ C ₂ O ₄直接共价键螯合来实现。。更重要的是，可以通过夹心免疫反应将聚多巴胺（PDA）涂覆的Fe ₃ O ₄引入电极上，从而实现明显的淬灭。猝灭机理主要表明，Ru（bpy）₃ ²⁺的激发态可以通过能量传递被PDA中的醌单元消除。ECL淬灭效率与NT-proBNP浓度在0.0005 ng / mL至100.0 ng / mL的范围内呈对数关系，检出限为0.28 pg / mL。此外，这种特异性免疫传感器具有良好的稳定性，可重复性以及选择性，这在NT-proBNP的基础和临床诊断中均具有指导意义。