Electrochemiluminescence Studies Based On Porphyrin Functionalized Composites

In recent years,based on the traditional electroluminescence system with low luminous efficiency,poor stability,narrow range of applications,biological toxicity and other shortcomings,many experts will study the new research standpoint electrochemical system through the ECL and other technologies.It can be used in many applications such as multiple co-reactant type,resonance energy transfer technology,self-enhanced electrochemiluminescence technology and so on.It has the advantages of high luminous efficiency,simple device,good stability and reproducibility,other technologies are used to increase the sensitivity and detection range of ECL technology.Today,with the development of nanomaterials and ECL technology,a variety of detection technologies have been used in the field of ECL to improve analytical performance.More and more ECL sensors have been constructed,such as DNA analysis,protein detection,immunoassay,cell testing etc,and electrocheluminescence has been widely used in many fields.In this dissertation,the enhanced electrochemiluminescence system was mainly studied and the electrochemiluminescence mechanism was discussed.1.An anode electrochemiluminescent?ECL?system of carbon nitride nanosheets+hydrogen peroxide+ vitamin B12 was constructed,the ECL signal of which were strong,stable and sensitivity under optimized reaction conditions.We found that the electrochemiluminescence intensity of the system was linear to vitamin B12 in the concentration extending from 2.5-105umol·L^-1,the lowest detection line was 1.2nmol·L^-1.In the meantime,the electro-luminescence mechanism of the system was discussed with the combination of electrochemical,ECL and UV.2.A original ECL luminophore was constructed using CNNS hybridized with TCPP.The TCPP-CNNS/K2S2O8 system could produce greatly enhanced ECL in buffer.A new dual-peak ECL signals for TCPP-CNNS/K2S2O8 system were explored in detail,one signal at-1.2 V(ECL^-1)and the other at-1.70 V?ECL-2?during the cyclic sweep between-0.2 V and-1.7 V.ECL-2 showed higher sensitivity under opimized conditions to acetaminophen?ACOP?than ECL^-1,thus was used for ECL sensor.The ECL sensor showed a sensitive linear response to ACOP in theconcentration extending from 0.002 to 120 umol·L^-1 with the detection limit of 0.2nmol·L^-1.3.An original ECL luminophore porphyrin nanosphere-graphene oxide composite?TCPP NS-GO?was prepared.The TCPP NS-GO could produce greatly enhanced ECL in buffer with K2S2O8 as the co-reactant.The enhancement ECL mechanism of TCPP NS-GO/K2S2O8 system was investigated in detail.Moreover,The TCPP NS-GO composite had an abundant surface functional group to expand its application,which exhibited high sensitivity and selectivity to Fe³⁺.The wide linear relationship between ECL intensity and Fe³⁺ concentration from 0.002 to 5.128 ?mol·L^-1?R2 =0.998?was found with the detection limit as low as 1 nmol·L^-1.The ECL quenching mechanism of Fe³⁺was proved by UV-vis absorption spectroscopy,Fluorescence emission spectroscopy?FL?and Fourier transform infrared spectroscopy?FT-IR?analysis technology.