非电极固定单颗粒限域电化学发光成像新策略  

A new electrogenerated chemiluminescence imaging strategy for non-electrode-immobilized single confinement luminescent particle

作　　者：杨小林 漆红兰[1] 张成孝[1] YANG Xiaolin;QI Honglan;ZHANG Chengxiao(Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province,School of Chemistry and Chemical Engineering,Shaanxi Normal University,Xi’an 710119,China)

机构地区：[1]陕西省生命分析化学重点实验室,陕西师范大学化学化工学院,陕西西安710119

出　　处：《延安大学学报（自然科学版）》2022年第3期10-17,共8页Journal of Yan'an University：Natural Science Edition

基　　金：国家自然科学基金项目(21974081,22074087)。

摘　　要：单细胞或单颗粒的电化学发光(ECL)成像法在细胞形貌和生物传感分析以及单颗粒表面催化机理方面的研究越来越受到研究者的重视。然而,微米级发光颗粒在电极表面的ECL成像受共反应试剂的传质、共反应试剂自由基寿命和颗粒光屏蔽效应等关键因素的影响尚未深入研究。受荧光成像法的启发,文章提出非电极固定单颗粒限域电化学发光成像新策略,即电极产生的共反应试剂自由基与非电极固定发光单颗粒进行化学反应而产生发光并进行成像。通过单颗粒逼近碳纤维(φ≈7.0μm)超微电极的电化学方法揭示了在扩散层内大粒径磁珠阻碍了电活性物质向电极表面的扩散。通过微米级发光磁珠(MB@SA/biotin-GSK-Ru1)吸附在工作电极表面的“正向”ECL成像法,发现大粒径发光磁珠的ECL强度远小于小颗粒发光磁珠的强度,揭示了磁珠接触电极使电极活性面积减小和磁珠的光屏蔽效应导致ECL强度降低。通过非电极固定单颗粒限域电化学发光成像新方法,发现电化学发光仅发生在共反应试剂自由基扩散层内,ECL强度也受到磁珠光屏蔽效应的影响,但是其光屏蔽效应影响小于“正向”ECL成像法。该研究工作为单颗粒限域电化学发光成像法研究提供了一种可选择的新策略。Electrogenerated chemiluminescence(ECL)imaging of single cells or single particles has attracted more and more attention in the study on cell morphology and biosensing analysis and the catalytic mechanism of single particle surfaces.However,the ECL imaging of micron-scale luminescent particles on the electrode surface is affected by key factors such as the mass transfer of the co-reactant,the radical lifetime of the co-reactant,and the particle light-shielding effect,which has not been deeply studied.Inspired by the fluorescence imaging method,this paper proposes a new strategy for confinement ECL imaging of non-electrode-immobilized single luminescent particles,that is,the co-reactant free radicals generated by the electrode and non-electrode-immobilized luminescent single particles chemically react to generate luminescence and perform imaging.Electrochemical method by single particle approximation of carbon fiber(φ≈7.0μm)ultramicroelectrode revealed that the large particle size magnetic beads(MB)in the diffusion layer hinder the diffusion of electroactive species to the electrode surface.Through the“positive”ECL imaging method of micron-scale luminescent magnetic beads(MB@SA/biotin-GSK-Ru1)adsorbed on the surface of the working electrode,it was found that the ECL intensity of the large-sized luminescent magnetic beads was much lower than that of the small-sized luminescent magnetic beads,revealing that the contact between the magnetic beads leads to the shrinkage of electrode active area and the shielding effect of magnetic beads reduces the ECL intensity.Through a new method of non-electrode immobilized single particle confinement ECL imaging,it was found that ECL only occurred in the radical diffusion layer of the coreactant,and the ECL intensity was also affected by the light shielding effect of magnetic beads,but the effect was weaker than that of“positive”ECL imaging method.This research provides a new ECL imaging strategy for nonelectrode-immobilized single luminescent particle.

关 键 词：电化学发光成像 单颗粒 磁珠 碳纤维电极 

分 类 号：O65[理学—分析化学]