Study On Electrogenerated Chemiluminescence Properties Of Modified Phenyl Porphyrins

As an ultra-sensitive analytical tool,electrogenerated chemiluminescence has attracted more and more attention from researchers.It is a relatively new technology formed via combinating electrochemistry with chemiluminescence.It mainly generates radical ions of the substances on the surface of the electrode due to electrical excitation,then,high energy chemical reaction occurs between the formed free radical ions.The process of high energy chemical reaction will form the excited states.Thereafter,the excited states return to the ground state,radiating energy in the form of light.In recent years,researchers have been working on the development of the new emitters with high efficiency,reproducibility and stability in order to adapt to multiple applications.Porphyrins is one of the most common emitters,and they are one of the best candidates for fabricating excellent sensing platform due to their stable intensity and close relationship between life activities.However,low solubility in water limits application in ECL field and our deep understanding of porphyrin compounds.Based on this,we have taken a series of measures to modify porphyrins,and studied the effects of active hydrogen substitution,formation of aggregates and different aggregation motifs on the electrogenerated chemiluminescence properties.To developing a series of new porphyrins-based sensors that can be used to rapidly identify and detect biological small molecules associated with diseases or for environmental analysis.This thesis includes the following four aspects:1.We mainly introduce the mechanism of electrogenerated chemiluminescence,main reaction types and its application.Secondly,the development history of electrogenerated chemiluminescence and porphyrins compounds are briefly introduced.Finally,the research status and application of porphyrins compounds in electrogenerated chemiluminescence field are described.2.Electrogenerated chemiluminescence as a technology,with high sensitivity and low detection limit and other advantages.The hydrolysis process of tetraphenylporphyrin tetrchlorosulfonic acid hydrate?TSPPCl?in aqueous solution produces tetraphenylporphyrin tetrasulfonic acid hydrate?TSPP?in situ.That can produce strong and stable cathodic electrogenerated chemiluminescence when K₂S₂O₈ is used as coreactant.3.A novel system based on electrochemically reduced graphene oxide?ERGO?enhanced aggregation of zinc?II?mesotetraphenylporphyrin?Zn TPP?/K₂S₂O₈ was proposed,constructing a stable and practical GSH sensing platform.The ERGO in the system indirectly improved detection sensitivity by accelerating the electron transport rates.4.The completely different electrogenerated chemiluminescence properties of zinc?II?meso-tetraphenylporphyrin?Zn TPP?caused by H-and J-aggregates were explored for the first time,providing a novel path to the excellent ECL emitter.Distinct H-and Jaggregates are formed due to different molecular arrangement.We have found for the first time that the electrogenerated chemiluminescence properties of J-aggregates are superior to that of H-aggregates.It is because the narrow band gap in J-aggregates and their own formation advantages.