Ding Li, Xu Shaohua, Huang Dandan, Chen Lifen, Kannan Palanisamy, Guo Longhua, Lin Zhenyu
Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian Province 350116, China.
Analyst. 2020 Oct 21;145(20):6524-6531. doi: 10.1039/d0an00864h. Epub 2020 Aug 6.
The detection of biomarkers in exhaled breath condensates (EBCs) is regarded as a promising non-invasive diagnostic approach. However, the ultralow concentration of biomarkers in EBCs is a great challenge. Herein, a sensitive dual signal amplification strategy was developed based on surface-enhanced electrochemiluminescence (SEECL) combined with resonance energy transfer (RET). Gold nanoparticles-functionalized graphite-like carbon nitride nanohybrids (Au-g-CN NHs) could be used as an energy transfer donor because of the good overlap between its emission peak and the absorption peak of tris(2,2'-bipyridine)ruthenium dichloride (Ru(bpy)Cl) at 460 nm. Gold-silicon dioxide core-shell nanoparticles doped with Ru(bpy)(Au@SiO-Ru) were employed as an energy transfer acceptor emitting at 620 nm. Moreover, the signals at 620 nm emitted by Ru (bpy) were enhanced by 5 times, attributed to the localized surface plasmon resonance (LSPR) of gold nanoparticles (Au NPs). The detection of carcinoembryonic antigen (CEA) was performed by using two aptamers as the recognition unit; whereby aptamer 1 (Apt1) was modified on the surface of Au-g-CN NHs, and aptamer 2 (Apt2) was banded on the surface of Au@SiO-Ru. In the presence of CEA, a sandwich structure was formed between Au-g-CN NHs-Apt1-CEA and Apt2-Au@SiO-Ru, which resulted in an ultrasensitive detection of CEA. The proposed electrochemiluminescence sensor showed a wide linear relationship with the CEA concentration in the range from 1.0 pg mL to 5.0 ng mL, with a limit of detection (LOD) of 0.3 pg mL. Finally, the practicality of the proposed sensor was demonstrated to detect CEA in EBCs, and the obtained results were in good agreement with the enzyme-linked immunosorbent assay (ELISA) method.
检测呼出气冷凝物（EBC）中的生物标志物被认为是一种很有前景的非侵入性诊断方法。然而，EBC中生物标志物的超低浓度是一个巨大的挑战。在此，基于表面增强电化学发光（SEECL）与共振能量转移（RET）相结合，开发了一种灵敏的双信号放大策略。金纳米颗粒功能化的类石墨氮化碳纳米杂化物（Au-g-CN NHs）可作为能量转移供体，因为其发射峰与二氯三（2,2'-联吡啶）钌（Ru(bpy)Cl）在460 nm处的吸收峰有良好的重叠。掺杂Ru(bpy)的金-二氧化硅核壳纳米颗粒（Au@SiO-Ru）用作在620 nm处发射的能量转移受体。此外，Ru(bpy)在620 nm处发射的信号因金纳米颗粒（Au NPs）的局域表面等离子体共振（LSPR）而增强了5倍。使用两种适体作为识别单元进行癌胚抗原（CEA）的检测；其中适体1（Apt1）修饰在Au-g-CN NHs表面，适体2（Apt2）结合在Au@SiO-Ru表面。在CEA存在的情况下，在Au-g-CN NHs-Apt1-CEA和Apt2-Au@SiO-Ru之间形成夹心结构，从而实现对CEA的超灵敏检测。所提出的电化学发光传感器与CEA浓度在1.0 pg/mL至5.0 ng/mL范围内呈现出宽线性关系，检测限（LOD）为0.3 pg/mL。最后，证明了所提出的传感器在检测EBC中CEA的实用性，所得结果与酶联免疫吸附测定（ELISA）方法高度一致。
