Development Of Three Electrochemiluminescence Sensors And Their Applications

The smart combination of chemiluminescence and electrochemistry brings electrochemiluminescence(ECL)many potential advantages.First,some reactants can be electrochemically regenerated at the electrode.This greatly enhances the sensitivity of the technique.The regeneration of reactants also simplifies the instrument,and saves the amount of reactants.Second,extremely unstable chemiluminescence reagents and intermediates can be electrogenerated in situ,and chemiluminescence analysis that needs extremely unstable reagent can be easily carried out by ECL analysis.Third,it is possible to electrochemically transform some compounds to species that can take part in a chemiluminescence reaction that would otherwise be inactive,and hence extends the range of analytes detection with a particular chemiluminescence reaction.Fourth,it allows greater control over the position of emission since the ECL emission is close to the electrode surface.The better control over the emission position is beneficial for sensitivity,selectivity,multi-analytes detection,and imaging analysis.Finally,ECL is relatively environmental and user-friendly,since it eliminates the use of toxic reagents.ECL sensor,as a cheap analytical method,has been widely studied.A solid-state ECL of immobilizing Ru(bpy)32+ on an electrode surface could shorten the electron-transfer path and then reduce the consumption of expensive Ru(bpy)32+.For purpose of overcoming its slow electron-transfer rate and poor long-term stability,various new nanomaterials with unique physical and chemical properties for fabricating Ru(bpy)32+ are being made,such as grapheme or carbon nanotubes.This thesis was focused on the development of solid-state ECL seosors and determination for dopamine(DA),melamine(MEL)and metformin(MET).The main results were described as follows:1.This work reports a sensitive electrochemiluminescence(ECL)detection strategy based on CNPs/CuNPs/Ru(bpy)32+/Nafion composite films modified glassy carbon electrode(GCE).The electrochemical and ECL behaviors of the sensor were investigated.By optimizing the experimental conditions,the proposed ECL sensor exhibited excellent analytical performances in detection of dopamine(DA)with a wide linear range(1 × 10-9-1 × 10-4 mol/L),low detection limit(3.3×10-10 mol/L),good reproducibility and acceptable stability.Furthermore,the proposed ECL sensor was applied for the determination of DA in dopamine hydrochloride injection samples with a desirable result,which holds a great potential in the field of pharmaceutical analysis.2.In order to determine melamine in milk,a new ECL sensor based on Ag/Nitrogen doped graphene nanoribbons(Ag/N-GNRs)has been developed.The electrochemical and ECL behaviors of the sensor were investigated.By optimizing the experimental conditions,the proposed ECL sensor exhibited excellent analytical performances in detection of melamine with a wide linear range(1×10-13-1×10-7 mol/L),low detection limit(3.3×10-14 mol/L),good reproducibility and acceptable stability.Furthermore,the proposed ECL sensor was applied for the determination of MEL in milk samples displayed a desirable result.3.A new ECL sensor which based on Ag/N-GNRs/g-C3N4 was designed in this thesis.By'optimizing the experimental conditions,the proposed ECL sensor exhibited excellent analytical performances in detection of melamine with a wide linear range(0.01-20 ng/mL),low detection limit(0.0033 ng/mL),good reproducibility and acceptable stability.The correlation coefficient is good(r2=0.9997)and the linear regression equation is 1=-407.29Log(CMET/ng×mL-1)-2007.92.