Wang Xiao-Yan, Zhu Kai-Di, Zhu Jin, Ding Shou-Nian
Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China.
Huadong Medical Institute of Biotechniques, Nanjing 210002, China.
Anal Chem. 2021 Feb 9;93(5):2959-2967. doi: 10.1021/acs.analchem.0c04613. Epub 2021 Jan 28.
In this work, a low triggered potential electrochemiluminescence strategy based on gold-filled photonic crystals (GPCs) electrodes composed of photonic crystals self-assembled with polystyrene spheres and gold nanoparticles embedded in the gaps of the photonic crystals was proposed. The GPCs electrodes served as the detection platform to bind antigen, and Ru(bpy)-COOH as a luminophore was labeled on the antibody (Ab). Then, Ru(bpy)-COOH/Ab was connected to the immobilized antigen on the surface of the photonic crystals by the immunoreaction to avoid direct contact with the gold nanoparticles surface. ECL emission can only be initiated by electrochemical oxidation of tripropylamine (TPrA) since Ru(bpy)-COOH cannot be oxidized directly on the electrode surface. The TPrA and TPrA radicals generated by the oxidation of TPrA can spread to the vicinity of Ru(bpy)-COOH over a short distance and react with the Ru(bpy)-COOH, eventually producing ECL emission. The potential of ECL emission caused by TPrA oxidation was about 300 mV lower than that caused by Ru(bpy)-COOH oxidation because the oxidation potential of TPrA (0.95 V vs SCE) was lower than Ru(bpy)-COOH (1.25 V vs SCE). Furthermore, the photonic crystals nanomembrane has the capability to enhance electrochemiluminescence. Thereafter, tetracycline antibiotic as a model compound was successfully detected via competitive immunoassay on GPCs electrodes with a detection limit of 0.075 pg/mL (S/N = 3), which has broad application prospects in the field of analysis and detection.
在本工作中，提出了一种基于金填充光子晶体（GPCs）电极的低触发电位电化学发光策略，该电极由聚苯乙烯球自组装的光子晶体和嵌入光子晶体间隙中的金纳米粒子组成。GPCs电极作为结合抗原的检测平台，将Ru(bpy)-COOH作为发光体标记在抗体（Ab）上。然后，Ru(bpy)-COOH/Ab通过免疫反应连接到光子晶体表面固定的抗原上，避免与金纳米粒子表面直接接触。由于Ru(bpy)-COOH不能在电极表面直接被氧化，所以只能通过三丙胺（TPrA）的电化学氧化引发电化学发光发射。TPrA氧化产生的TPrA和TPrA自由基可以在短距离内扩散到Ru(bpy)-COOH附近并与Ru(bpy)-COOH反应，最终产生电化学发光发射。TPrA氧化引起的电化学发光发射电位比Ru(bpy)-COOH氧化引起的电位低约300 mV，因为TPrA的氧化电位（相对于SCE为0.95 V）低于Ru(bpy)-COOH（相对于SCE为1.25 V）。此外，光子晶体纳米膜具有增强电化学发光的能力。此后，以四环素抗生素为模型化合物，通过在GPCs电极上的竞争免疫分析成功检测到，检测限为0.075 pg/mL（S/N = 3），在分析检测领域具有广阔的应用前景。
