DataSheet1_A highly sensitive immunosensor based on nanochannel-confined nano-gold enhanced electrochemiluminescence for procalcitonin detection.pdf

Sensitive detection of procalcitonin (PCT) in serum is crucial for the timely diagnosis and treatment of rheumatoid arthritis. In this work, an electrochemiluminescence (ECL) detection platform is developed based on in-situ growth of Au nanoparticles (AuNPs) in nanochannels and an analyte-gated detection signal, which can realize ECL determination of PCT with high sensitivity. Vertically ordered mesoporous silica films with amine groups and uniform nanochannel array (NH2-VMSF) is easily grown on the supporting indium tin oxide (ITO) electrode through electrochemical assisted self-assembly method (EASA). Anchored by the amino groups, AuNPs were grown in-situ within the nanochannels to catalyze the generation of reactive oxygen species (ROS) and amplify the ECL signal of luminol. An immuno-recognitive interface is constructed on the outer surface of NH2-VMSF, through covalent immobilization of PCT antibodies. In the presence of PCT, the immunocomplex will hinder the diffusion of luminol and co-reactants, leading to a gating effect and decreased ECL signals. Based on this principle, the immunosensor can detect PCT in the range from 10 pg/mL to 100 ng mL-1 with a limit of detection (LOD) of 7 pg mL-1. The constructed immunosensor can also be used for detecting PCT in serum. The constructed sensor has advantages of simple fabrication and sensitive detection, demonstrating great potential in real sample analysis.

血清中降钙素原（procalcitonin, PCT）的高灵敏检测对于类风湿关节炎的及时诊断与治疗具有关键意义。本研究构建了一种基于纳米通道内金纳米颗粒（Au nanoparticles, AuNPs）原位生长与分析物门控检测信号的电致化学发光（electrochemiluminescence, ECL）检测平台，可实现高灵敏度的PCT电致化学发光定量检测。采用电化学辅助自组装法（electrochemical assisted self-assembly method, EASA），可在支撑用氧化铟锡（indium tin oxide, ITO）电极表面便捷生长带氨基基团、拥有规整纳米通道阵列的垂直有序介孔二氧化硅薄膜（amine-functionalized vertically ordered mesoporous silica films, NH2-VMSF）。借助氨基基团的锚定作用，AuNPs在纳米通道内原位生长，催化活性氧物种（reactive oxygen species, ROS）的生成并放大鲁米诺的ECL信号。在NH2-VMSF的外表面构建免疫识别界面，通过共价固定PCT抗体实现。当体系中存在PCT时，免疫复合物会阻碍鲁米诺与共反应试剂的扩散，进而产生门控效应并降低ECL信号强度。基于该原理，所制备的免疫传感器可在10 pg/mL至100 ng/mL的浓度范围内检测PCT，检出限（limit of detection, LOD）为7 pg/mL。所构建的免疫传感器亦可用于血清样本中PCT的检测。该传感器具备制备流程简便、检测灵敏度高的优势，在实际样本分析中展现出良好的应用潜力。