Based On Electrochemical Luminescence Sensing Properties Of Aromatic Structure-Based Luminescent Substances

With the development of economy and the progress of science and technology,in the modern world,there is an increasing demand for monitoring human health through trace detection of certain substances.Electrochemicalluminescence(ECL)method is often used by some researchers to realize the trace detection of some substances because of its advantages such as high sensitivity and low noise.For the study of electrochemical luminescence sensing performance,luminescent substances and electrode materials are important component factors for studying the sensing performance.It largely determines the linear range,detection limit,sensitivity,stability and of the test object.Electrochemiluminescence is a kind of luminescence phenomenon caused by luminescent substances under the excitation of voltage.ECL is a commonly used analytical method,which has the advantages of wide linear range,high sensitivity,and low detection limit.ECL is widely used in many fields,such as: food safety testing,environmental monitoring,biological testing,etc.This thesis focuses on experiments with several substances with aromatic hydrocarbon structures as luminescent substances.It focuses on the use of electrochemical luminescence methods to detect a few substances and achieve the purpose of optical imaging analysis.The luminescence mechanism was reasonably analyzed.This thesis consists of the following five parts:The chapter ? gives an overview of the development and basic principles of electroluminescence.Next,the common electroluminescence systems are introduced,and the electroluminescence mechanisms of these systems are described.Finally,the luminescent materials with aromatic structure and their applications in electrochemical luminescence are reviewed,and the concept of this article is explained.The chapter ? mainly studied the detection of dopamine by using a boron-nitrogen-containing aromatic hydrocarbon structural substance as a luminescent substance.In this work,a three-electrode system was used,and the electrochemical luminescence intensity was measured using cyclic voltammetry.Using a phosphate buffer solution(PBS)of pH = 7 as the buffer system,adding different concentrations of the dopamine test solution,according to different dopamine concentrations corresponding to different electrochemical luminous intensity(the greater the concentration of dopamine,the corresponding electrochemical The stronger the luminous intensity),draw a linear curve and get the corresponding linear regression equation Y = 100.21 X + 6.74(R2 = 0.99),where Y is the electrochemical luminescence intensity corresponding to the dopamine test solution at different concentrations,and X is the dopamine concentration.The linear interval of the dopamine concentration detected by the electroluminescence method was 5.226 × 10^-4M-0.4M,and the detection limit was 5.226 × 10^-4M.Because this boron-nitrogen-containing aromatic hydrocarbon structural substance has been experimentally proven to have a low intensity of the electroluminescence signal,and the resulting optical image cannot meet the requirements for optical imaging analysis,the following work was carried out.The chapter ? mainly researched the iridium and ruthenium metal complexes with aromatic structure as the light-emitting substances for electrochemical luminescence.In this work,a group of highly water-soluble aryl-structured iridium and ruthenium metal complexes were selected.Carbon paper was used as the working electrode,Ag/AgCl electrode was used as the reference electrode,platinum electrode was used as the counter electrode,and tripropylamine was used as the electrode.In the case of a co-reactant,cyclic voltammetry was also used to perform the electroluminescence experiment,and all the complexes were detected to have an electroluminescence signal.The experiment proves that the ruthenium-based metal complex with aromatic structure has higher electrochemical luminescence signal intensity and can meet the requirements for optical imaging analysis.After the above research,Ru(bpy)₃²⁺,which is also a ruthenium metal complex with an aromatic structure,was selected as the luminescent substance.In chapter ? mainly studied the detection of acrylamide and analysis of optical images by electroluminescence method of Ru(bpy)₃²⁺.In this work,Ru(bpy)₃²⁺,which is also an aromatic hydrocarbon structure,was used as a luminescent substance to detect acrylamide.Under the optimal conditions,the linear range of acrylamide detected was 5 ?M to 10 mM,and the detection limit was 1.2 ?M(S / N = 3).The obtained linear fitting equation is Y = 700.15299X-310.20364,where Y represents the value of the intensity of the electroluminescence signal,and X represents the logarithm of the acrylamide concentration(lg).In addition,a remote wireless camera is used to collect the digital images generated by the electroluminescent signal.These images were converted from RGB(red,green,blue)models to HSV(hue,saturation,brightness)models by MATLAB software.It can be seen that the luminance value(V)in the HSV model has a linear relationship with the logarithm of the acrylamide concentration.The obtained linear fitting equation is Y = 0.10458 X + 0.01653,where Y represents the brightness value(V)corresponding to the intensity of the electroluminescent signal,and X represents the logarithm(lg)value of the acrylamide concentration.It turns out that the combination of electrochemical luminescence and optical image analysis is simple and easy to detect acrylamide,and it is expected to develop into a new acrylamide detection method in food safety and other fields.The chapter ? summarizes the research work,point out the problems and deficiencies,and look forward to future research.