Construction Of Stannate-base Ratiometric Electrochemiluminescence Sensor And Its Application In Food Detection

Ratiometric electrochemiluminescence（RECL）not only has many superiorities such as high sensitivity,selectivity,and low background signal but also can effectively reduce the impact of instruments or external environments on analysis accuracy.It has been widely used in the detection of metal ions,disease markers,and food safety.Unfortunately,current research is mainly focused on the successful construction of RECL and implementation for detecting targets.The limited exploration and research on the structure-activity relationship between the structure and performance of stannate-based luminescent materials.Therefore,it is crucial to deeply understand the relationship between the structure and performance of luminescent materials,and reasonably develop novel luminescent materials with stable performance,which has important guiding significance for achieving specific detection of targets.Based on the above discussion,in this paper,two kinds of stannate-based luminescent materials were developed and their luminescent mechanism has been preliminarily explored.And we have successfully constructed the innovative RECL that provides new ideas for food safety monitoring.1.According to the interface engineering strategy,CdZnS/Eu₂Sn₂O₇ with enriched oxygen vacancies（OVs）were elaborately designed as cathode luminescent materials.The ratiometric electrochemiluminescence（RECL）sensing system was reasonably constructed though incorporating biomass-derived nitrogen doped carbon dots（BD-NCDs）as the anode material.CdZnS/Eu₂Sn₂O₇ possessed the ability to achieve self-reinforced RECL though employing heterointerfaces and OVs as the main catalytic active sites,respectively.Both experiments and density functional theory（DFT）calculations systemically revealed that the formation of Zn/Cd-S-Sn bond at the interface was induced,which promoted electron transfer and electrochemical reaction kinetics,and the catalytic ability of H₂O₂ to generate·OH was increased by 4.7 times and 14.4 times,respectively;And OVs directly participate in the electrochemical reaction as the active site for catalyzing H₂O₂ to generate an abundance of O₂^·-to accomplish sharp amplification of the anode signal by 5.7-fold,compared to BD-NCDs.Additionally,profit from outstanding the self-reinforcing effect of CdZnS/Eu₂Sn₂O₇,the sensing system was designed to sensitively detect sunset yellow from 0.1 to 4000 nmol/L.More importantly,the integrated smartphone sensor device has successfully implemented the portable detection of SY.This will provide new ideas for exploring the self-enhancing RECL system,and also broaden the potential of integrated RECL for smartphones in the field of detection.2.To further improve the specificity,selectivity,and sensitivity of RECL,and expand their applications in freshness.Combined with molecular imprinting technology（MIT）,Ce₂Sn₂O₇ and Ru（bpy）₃²⁺emitters act as cathode and anode electrochemiluminescence（ECL）luminophores in the presence co-reactant K₂S₂O₈ and tripropylamine,respectively.Based on the in-situ electropolymerization method as the capture and signal amplification probe,the designed a novel and portable visual dual-potential（-1.8V and +1.2V）molecularly imprinted ratiometric electrochemiluminescence（MIRECL）sensor for tyramine（Try）detection with a wide linear range from 0.01μmol/L to 1000μmol/L and the detection limit was low to 0.005μmol/L.Interestingly,combined with the principle of optical signal reading by smartphone,the developed MIRECL exhibited excellent sensitivity and specificity for Try analysis in actual shrimp and fish samples,which provides a new idea for on-site detection of agricultural food freshness.