Imaging electrochemiluminescence layer to dissect concentration-dependent light intensity for accurate quantitative analysis  

作　　者：Wen-Xuan Fu Ping Zhou Wei-Liang Guo Bin Su 

机构地区：[1]Key Laboratory of Excited-State Materials of Zhejiang Province,Institute of Analytical Chemistry,Department of Chemistry,Zhejiang University,Hangzhou 310058,China [2]School of Chemistry and Materials Science,Nanjing Normal University,Nanjing 210023,China

出　　处：《Advanced Sensor and Energy Materials》2022年第3期24-30,共7页先进传感器与能源材料（英文）

基　　金：support from the National Natural Science Foundation of China(22125405,22074131 and 21874117)is acknowledged.

摘　　要：As one of most advanced transduction techniques,electrochemiluminescence(ECL),such as that generated by tris(2,20-bipyridyl)ruthenium(Ru(bpy)32þ),has been extensively used in chemical sensing and analysis,but the reaction mechanism has not been fully resolved.Aiming at gaining insightful mechanistic information on the coreactant system involving(Ru(bpy)32þ)and tri-n-propylamine(TPrA),herein we investigate the variation of thickness of ECL layer(TEL)with the concentration ratio of(Ru(bpy)32þ)to TPrA(cRu/cTPrA)by ECL microscopy.Using carbon fiber as the working electrode,TEL was observed to grow with the increase of cRu/cTPrA remarkably.In conjunction with finite element simulations,the extension of ECL layer was rationalized to be associated with the incremental contribution of so-called“catalytic route”.This route offers an additional channel of generating remote light emission in solution,apart from surface-confined emission produced by the“oxidative-reduction route”.Given the quantitative analysis of coreactant-type analytes is often based on the calibration curve,namely a graph generated by plotting the measured light intensity of a series of standard solutions against their concentrations,the contribution of“catalytic route”particularly at a low concentration of analyte(equivalent to a relatively large cRu/cTPrA)is favorable to the analytical sensitivity.Moreover,the presence and absence of this route will result in a nonlinear and linear calibration curve,respectively,for example in the detection of TPrA and pyruvate.The results highlight the microwire-based imaging approach can provide insightful mechanistic information and help unveil the concentration dependence of measured ECL intensity for precise quantitative analysis.

关 键 词：Reaction mechanism ECL microscopy ECL layer thickness ECL analysis Calibration curve 

分 类 号：O64[理学—物理化学]