Aggregation-Enhanced Electrochemiluminescence Based On Ruthenium Complexes For Lidocaine Detection

Electrochemiluminescence（ECL）technology is widely used in the field of sensing due to its advantages such as high sensitivity,low background noise,simple instrumentation,and wide linear range.However,the current mainstream research trend in ECL leans towards the intricate design of organic molecules,aiming to enhance their luminescence intensity and efficiency by adjusting the structure and conformation of the luminescent molecules.This path is relatively time-consuming and labor-intensive.Therefore,exploring straightforward and efficient strategies,such as employing aggregation-enhanced ECL or composite functional nanomaterials to construct efficient ECL sensors,can optimize the sensitivity and detection range of ECL sensors.These strategies involve regulating intermolecular forces or utilizing the physical encapsulation of ECL luminescent molecules to promote their aggregation by implementing confinement or binding approaches.Lidocaine is a drug widely used for local anesthesia and arrhythmia treatment.Overdose or misuse of lidocaine can lead to a series of adverse reactions.Current methods for lidocaine detection,including chromatography,capillary electrophoresis,mass spectrometry,and nuclear magnetic resonance,have significant limitations in terms of sensitivity and selectivity.Therefore,it is clinically important to utilize ECL technology with appropriate interference scavengers to accurately and rapidly determine lidocaine.The specific work of this paper is as follows:1.We proposed a simple and efficient galvanic process,dedicated to optimizing the ECL luminescence properties of ruthenium complexes by adjusting the electrostatic interactions between molecules within the aggregate.Compared with traditional ruthenium complexes,the ECL strength and efficiency of ruthenium complexes with aggregation-enhanced ECL properties were significantly enhanced by 8.9 times and13.6 times,respectively.What is particularly striking is that the target ECL aggregates exhibited unprecedented excellent stability under a variety of scan rates and temperatures.In addition,we cleverly integrated carbon paper into the ECL system for the first time,constructed an efficient ECL device without any binder,and successfully achieved an excellent detection limit of 0.34 nM and excellent selectivity for lidocaine.2.This study innovatively introduced NO₂^-as an amine scavenger for the first time,cleverly eliminating the influence of amine interferents as coreactants of ruthenium complexes,thus achieving extremely high selectivity for lidocaine detection.We further prepared Co₃O₄@Ru aggregate material,where Co₃O₄ exhibited a significant catalytic effect in the ECL reaction between Ru（bpy）₃²⁺and lidocaine,achieving ultrasensitive detection of lidocaine（detection limit:0.32 n M）.We also deeply explored the potential mechanism of this enhanced ECL,providing solid experimental evidence for the actual role of Co₃O₄ in the Ru（bpy）₃²⁺-coreaction system.Moreover,the Co₃O₄@Ru-based ECL sensor obtained outstanding detection rates and repeatability in actual detection of human serum samples,verifying the application potential of Co₃O₄@Ru in clinical medical detection.3.We successfully preparing two-dimensional nanomaterial Ni Mo S using a one-step hydrothermal method,effectively promoting the aggregation process of ruthenium complexes.Experimental results showed that the ECL efficiency of Ru@Ni Mo S reached up to 70.1%,which is 36.9 times that of pure Ru,and its ECL intensity reached172.2 times that of Ru.In the Ru（bpy）₃²⁺/tripropylamine system,Ni Mo S played multiple key roles,such as a structural stabilizer,an electrochemical catalyst,and an oxygen evolution reaction promoter.Based on these unique properties,we designed a high-efficiency ECL sensor for lidocaine detection.This sensor displayed an excellent linear response in the concentration range of 1 n M to 1μM,and its detection limit was only 0.22 nM,demonstrating great application potential.