Fabrication Of Novel Sulfate Radicals Mediated Electrochemiluminescence Sensor And The Applications For The Detection Of Perfluorochemicals

In the 21 century,with the development of science and technology,the increase in demand,large numbers of chemicals have been used and aroused serious pollution.Therefore,rapid determination and reliable quantification of environment pollutants have become the key step for homeland security and health protection.A representative of the major chemical pollutant in the environment,the traditional detection methods for perfluorochemicals(PFCs)include GC-MS,LC-MS,LC-MSMS.However,these methods always require complicated pretreatment steps and expensive labor resources.Compared with traditional detection methods,electeochemiluminescence(ECL)detection has several advantages,such as simple instruments,low cost,high sensitivity and good stability.As known,PFCs are chemically inert with extremely strong carbon-fluorine bonds(C-F,116 kcal mol-1),making them resistant to conventional advanced oxidation processes,such as TiO2,hydroxyl radicals and traditional Feton reagents.Peroxydisulfate ion was found to be an efficient photochemical oxidant for the decomposition of PFOA,because of the generated highly powerful oxidants of sulfate radicals(SO4-.E0= + 2.3 eV)during the photolysis of S2O82-.The powerful oxidant of sulfate radicals could be generated by the reduction of peroxydisulfate ion(used as the co-reactant during ECL system).Based on the above knowledge,several novel sulfate radicals mediated ECL sensors have been developed using S2O82-as coreactant for the detection of PFCse in this thesis:1.A novel electrochemiluminescence(ECL)sensor has been first developed for the detection of PFOA using the molecularly imprinted polypyrrole modified two-dimensional ultrathin g-C3N4(utg-C3N4)nanosheets as a cathodic ECL emitter with S2O82-as coreactant.The prepared molecularly imprinted polymer(MIP)functionalized utg-C3N4 nanosheets(MIP@utg-C3N4)exhibit a stable and significantly amplified ECL signal.It is found that the targets of PFOA could be efficiently oxidized by the electro-generated strong oxidants of SO4-(from the reduction of coreactant S2O82-),thus leading to a low yield of the excited utg-C3N4(g-C3N4*)and finally a decrease in ECL signal.Such a newly ECL detection sensor has remarkably sensitivity,selectivity and good stability.In the practical applications,this sensor was successfully applied to detection PFOA in real water samples,showing fine practical value in environment pollutants detection.2.A novel electrochemiluminescence(ECL)sensor has been developed.Such ECL sensor fabricated by gold nanoparticle-ultrathin g-C3N4 nano sheet nanohybrids(AuNP-utg-C3N4 NHs)with S2O82-as coreactant.Using AuNP-utg-C3N4 NHs and3.1h,1H,2H,2H-Perfluorodecanethiol as ECL probe.1H,1H,2H,2H-Perfluorode-canethiol has a lot of C-F bond,it possess excellent specific affinity to PFCs by the interaction of fluorine fluorine bond.For this reason,this sensor showed good selectivity.And moreover,it has been explored to detect perfluorooctane sulfonates(PFOS)in the real samples.4.A novel electrochemiluminescence(ECL)sensor has been developed for the detection of PFOA using the molecularly imprinted polymer modified graphene nanosheets(GNs)and carbon quantum dot as cathodic ECL sensor.Owing to the good conductivity from gold nanoparticles and graphene nanosheets,it greatly enhanced the sensitivity of the as-prepared sensor.The smart integration of molecularly imprinted gold nanoparticles-polypyrrole polymer(AuNPs-PPy),graphene nanosheets(GNs)and carbon quantum dot yields a cathodic ECL emitter with S2O82-as coreactant.This newly designed ECL sensor has remarkable sensitivity,selectivity and good stability.