Song Xianzhen, Zhao Lu, Luo Chuannan, Ren Xiang, Yang Lei, Wei Qin
Collaborative Innovation Center for Green Chemical Manufacturing and Accurate Detection, Key Laboratory of Interfacial Reaction & Sensing Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, Shandong 250022, China.
Anal Chem. 2021 Jul 20;93(28):9704-9710. doi: 10.1021/acs.analchem.1c00850. Epub 2021 Jul 9.
A copper-based metal-organic framework (JUC-1000) has emerged as a promising electrochemiluminescence (ECL) emitter in the domains of bioanalysis and immunoassay. Herein, a highly efficient signal "on-off" peptide-based biosensor was constructed for trypsin (TPN) assay. JUC-1000 synthesized using an organic ligand of HBDPO was functionalized as the ECL emitter, whose cathodic ECL behavior in aqueous media was first investigated using potassium persulfate (KSO) as the coreactant. To further amplify the ECL signal, highly catalytic Ag@CeO nanoparticles were fabricated as both a substrate and an coreaction accelerator, which can efficiently catalyze the reduction of SO to generate more sulfate anion radicals (SO) for ECL enhancement, thereby generating strong and stable ECL signals in a "signal on" state. The functionalized JUC-1000 emitter was connected to the Ag@CeO sensing layer though a heptapeptide (HWRGWVC, HGC), and TPN as the target can specifically cleave the carboxyl side of arginine residues in HGC, leading to the release of emitters in a "signal off" state. Based on the efficient signal-switching, the biosensor exhibited linear ECL responses to the added TPN concentration, realizing sensitive detection of TPN in 10 fg/mL to 100 ng/mL with a limit of detection of 3.46 fg/mL. This work proposed an attractive orientation for the fundamental research of applying transition metal-organic frameworks as ECL emitters in bioanalysis and immunoassay.
一种铜基金属有机框架（JUC-1000）已成为生物分析和免疫测定领域中一种有前景的电化学发光（ECL）发光体。在此，构建了一种用于胰蛋白酶（TPN）测定的高效基于肽的信号“开-关”生物传感器。使用HBDPO有机配体合成的JUC-1000被功能化为ECL发光体，首次以过硫酸钾（KSO）作为共反应剂研究了其在水性介质中的阴极ECL行为。为了进一步放大ECL信号，制备了具有高催化活性的Ag@CeO纳米颗粒作为底物和共反应促进剂，其可以有效催化SO的还原以产生更多硫酸根阴离子自由基（SO）用于增强ECL，从而在“信号开”状态下产生强而稳定的ECL信号。功能化的JUC-1000发光体通过七肽（HWRGWVC，HGC）连接到Ag@CeO传感层，作为靶标的TPN可以特异性切割HGC中精氨酸残基的羧基侧，导致发光体以“信号关”状态释放。基于这种有效的信号切换，该生物传感器对添加的TPN浓度呈现线性ECL响应，实现了在10 fg/mL至100 ng/mL范围内对TPN的灵敏检测，检测限为3.46 fg/mL。这项工作为将过渡金属有机框架作为ECL发光体应用于生物分析和免疫测定的基础研究提出了一个有吸引力的方向。
