School of Chemistry and Chemical Engineering, University of Jinan , Jinan 250022, China.
School of Mechanical and Materials Engineering, Washington State University , Pullman, Washington 99164, United States.
Anal Chem. 2018 Feb 6;90(3):1976-1982. doi: 10.1021/acs.analchem.7b04068. Epub 2018 Jan 22.
Numerous analytical techniques have been undertaken for the detection of protein biomarkers because of their extensive and significant applications in clinical diagnosis, whereas there are few strategies to develop dual-readout immunosensors to achieve more accurate results. To the best of our knowledge, inspired by smart drug delivery system (DDS), a novel pH-responsive modified enzyme-linked immunosorbent assay (ELISA) was innovatively developed for the first time, realizing dual-modal colorimetric and fluorescent detection of cardiac troponin I (cTnI). Curcumin (CUR) was elaborately selected as a reporter molecule, which played the same role of drugs in DDS based on the following considerations: (1) CUR can be used as a kind of pH indicator by the inherited allochroic effect induced by basic pH value; (2) the fluorescence of CUR can be quenched by certain nanocarriers as the acceptor because of the occurrence of fluorescence resonance energy transfer (FRET), while recovered by the stimuli of basic pH value, which can produce "signal-on" fluorescence detection. Three-dimensional MoS nanoflowers (3D-MoS NFs) were employed in immobilizing CUR to constitute a nanoprobe for the determination of cTnI by virtue of good biocompatibility, high absorption capacity, and fluorescence quench efficiency toward CUR. The proposed DDS-inspired ELISA offered dual-modal colorimetric and fluorescent detection of cTnI, thereby meeting the reliable and precise analysis requirements. We believe that the developed dual-readout ELISA will create a new avenue and bring innovative inspirations for biological detections.
已经采用了许多分析技术来检测蛋白质生物标志物，因为它们在临床诊断中有广泛而重要的应用，而开发双读取免疫传感器以获得更准确结果的策略却很少。据我们所知，受智能药物输送系统 (DDS) 的启发，我们首次创新性地开发了一种新型的 pH 响应修饰酶联免疫吸附测定 (ELISA)，实现了心肌肌钙蛋白 I (cTnI) 的双模式比色和荧光检测。姜黄素 (CUR) 被精心选为报告分子，这是基于以下考虑因素：(1)CUR 可以用作一种 pH 指示剂，因为基本 pH 值会引起固有的变色效应；(2)CUR 的荧光可以被某些纳米载体作为受体猝灭，因为发生了荧光共振能量转移 (FRET)，而碱性 pH 值的刺激可以恢复，从而产生“信号开启”荧光检测。三维 MoS 纳米花 (3D-MoS NFs) 被用于固定 CUR，以构成用于通过良好的生物相容性、高吸收能力和对 CUR 的荧光猝灭效率来测定 cTnI 的纳米探针。所提出的基于 DDS 的 ELISA 提供了 cTnI 的双模式比色和荧光检测，从而满足了可靠和精确分析的要求。我们相信，开发的双读取 ELISA 将为生物检测开辟新途径，并带来创新灵感。
