Zhang Kai, Dong Haifeng, Dai Wenhao, Meng Xiangdan, Lu Huiting, Wu Tingting, Zhang Xueji
Research Center for Bioengineering and Sensing Technology, Beijing Key Laboratory for Bioengineering and Sensing Technology, School of Chemistry and Bioengineering, University of Science & Technology Beijing , Beijing 100083, P.R. China.
Department of Environmental Science and Engineering, School of Chemistry and Environment, Beijing University of Aeronautics & Astronautics , Beijing 100083, P.R. China.
Anal Chem. 2017 Jan 3;89(1):648-655. doi: 10.1021/acs.analchem.6b02858. Epub 2016 Dec 19.
Herein, an efficient electrochemical tracer with advanced oxygen reduction reaction (ORR) performance was designed by controllably decorating platinum (Pt) (diameter, 1 nm) on the surface of compositionally tunable tin-doped indium oxide nanoparticle (Sn-InO) (diameter, 25 nm), and using the Pt/Sn-InO as electrochemical tracer and interfacial term hairpin capture probe, a facile and ultrasensitive microRNA (miRNA) detection strategy was developed. The morphology and composition of the generated Pt/Sn-InO NPs were comprehensively characterized by spectroscopic and microscopic measurements, indicating numerous Pt uniformly anchored on the surface of Sn-InO. The interaction between Pt and surface Sn as well as high Pt(111) exposure resulted in the excellent electrochemical catalytic ability and stability of the Pt/Sn-InO ORR. As proof-of-principle, using streptavidin (SA) functionalized Pt/Sn-InO (SA/Pt/Sn-InO) as electrochemical tracer to amplify the detectable signal and a interfacial term hairpin probe for target capture probe, a miRNA biosensor with a linear range from 5 pM to 0.5 fM and limit of detection (LOD) down to 1.92 fM was developed. Meanwhile, the inherent selectivity of the term hairpin capture probe endowed the biosensor with good base discrimination ability. The good feasibility for real sample detection was also demonstrated. The work paves a new avenue to fabricate and design high-effective electrocatalytic tracer, which have great promise in new bioanalytical applications.
在此，通过在可调控组成的锡掺杂氧化铟纳米颗粒（直径25 nm）表面可控地修饰铂（直径1 nm），设计出一种具有先进氧还原反应（ORR）性能的高效电化学示踪剂，并将Pt/Sn-InO用作电化学示踪剂和界面末端发夹捕获探针，开发了一种简便且超灵敏的微小RNA（miRNA）检测策略。通过光谱和显微镜测量对生成的Pt/Sn-InO纳米颗粒的形态和组成进行了全面表征，表明大量的铂均匀地锚定在Sn-InO表面。铂与表面锡之间的相互作用以及高暴露的Pt(111)导致了Pt/Sn-InO ORR优异的电化学催化能力和稳定性。作为原理验证，使用链霉亲和素（SA）功能化的Pt/Sn-InO（SA/Pt/Sn-InO）作为电化学示踪剂来放大可检测信号，并使用界面末端发夹探针作为目标捕获探针，开发了一种线性范围为5 pM至0.5 fM且检测限低至1.92 fM的miRNA生物传感器。同时，末端发夹捕获探针固有的选择性赋予了该生物传感器良好的碱基区分能力。还证明了该生物传感器在实际样品检测中的良好可行性。这项工作为制造和设计高效电催化示踪剂开辟了一条新途径，在新的生物分析应用中具有巨大潜力。
