| Electrochemiluminescence(ECL) is a kind of technique which combines electrochemistry and chemiluminescence. ECL introduces some outstanding features such as high sensitivity, simple operation and fast detection. The ECL dection of immune molecule, DNA and small molecule has been realized, and it has good application prospects in clinical research, food industry and environmental detection and analysis. In this paper, we have construted ECL sensors for dopamine, phenolic substances and melamine detection using S2O82-–O2 system, g-C3N4–S2O82- system,PTC–NH2–S2O82- system and PFO-C2O42- system, respectively.Part 1 An electrogenerated chemiluminescence sensor based on gold nanoflower@C60 hybrid for the determination of phenolic compoundsThis paper described a novel strategy for the construction of an electrogenerated chemiluminescence(ECL) sensor based on gold nanoflower@C60(Au NPs@C60)hybrid for detecting phenolic compounds. First, C60 was functionalized with L-cysteine. Subsequently, with C60 as the core, gold nanoparticles(Au NPs) are synthesized and grown through an in situ reduction method in the presence of ascorbic acid(AA). The resulted flowerlike Au NPs@C60 nanoparticles were modified onto the glassy carbon electrode to achieve the sensor(Au NPs@C60/GCE). Here, L-cysteine not only can improve the biocompatibility and hydrophilicity of C60 but also can enhance the electrogenerated chemiluminescence(ECL) of peroxydisulfate system.Furthermore, both Au NPs and C60 are also beneficial to the ECL of peroxydisulfate system. Due to the combination of L-cysteine, Au NPs and C60, the proposed ECL sensor exhibited an excellent analytical performance. Under the optimum condition,the ECL intensity increased linearly with phenolic compounds. The linear ranges of6.2×10-8~1.2×10-4 mol·L-1, 5.0×10-8~ 1.1×10-4 mol·L-1 and 5.0×10-8~ 1.1×10-4mol·L-1 were obtained for the catechol(CC), hydroquinone(HQ) and p-cresol(PC),respectively, and the detection limits were 2.1×10-8 mol·L-1, 1.5×10-8 mol·L-1and1.7×10-8 mol·L-1, respectively. The Au NPs@C60 hybrid might hold a new opportunity to develop an ECL sensor.Part 2 Enhanced electrochemiluminescence sensor for detecting dopamine based on gold nanoflower@graphitic carbon nitride polymer nanosheet-polyaniline hybridIn this work, an enhanced electrochemiluminescence(ECL) sensor based on gold nanoflower@graphitic carbon nitride polymer nanosheet-polyaniline hybrid(Au NPs@g-C3N4-PANI) was prepared for the detection of dapamine(DA). Firstly, the bulk g-C3N4 was prepared through polymerizing melamine under 600℃. And then the g-C3N4 nanosheet was obtained by ultrasonication-assisted liquid exfoliation of bulk g-C3N4. Finally, polyaniline(PANI) and gold nanoflower(Au NPs) were successively formed on g-C3N4 nanosheet through an in situ synthesis method. The resulted Au NPs@g-C3N4-PANI hybrids were modified onto the surface of glassy carbon electrode to achieve a sensor(Au NPs@g-C3N4-PANI/GCE) for detecting dopamine.Under the optimal conditions, the ECL signal increased linearly with the concentration of dopamine. The linear range of 5.0×10-9~1.6×10-6 mol·L-1 was obtained, while the detection limit was 1.7×10-9 mol·L-1. The prepared sensor exhibited a low detection limit and high sensitivity for the determination of dopamine.The combination of g-C3N4 nanosheet, PANI and Au NPs would provide a new opportunity for the ECL sensor.Part 3 Cathodic electrochemiluminescence behavior of an ammonolysis product of 3,4,9,10-perylenetetracarboxylic dianhydride in aqueous solution and its Application for detecting dopamineThe cathodic electrochemiluminescence(ECL) behavior of ammonolysis product of 3,4,9,10-perylenetetracarboxylic dianhydride(PTC-NH2) in aqueous solution with K2S2O8 as the coreactant has been the first time reported in this paper. The possible mechanisms have been investigated. Based on the fact that dopamine(DA) can effciently quench the ECL intensity of PTC-NH2, DA was chosen as a template to investigate the application of PTC-NH2-S2O82- system in the sensor field. Under the optimal conditions, we achieved the detection of DA with the linear range of 5.0×10-9~ 1.1×10-6 mol·L-1 and the detection limit of 1.6×10-9 mol·L-1. Due to the excellent ECL behavior, the PTC-NH2 could be a new class of promising material to construct ECL sensors.Part 4 Conjugated polymer dots/oxalate anodic electrochemiluminescence system and its application for detecting melamineIn this work, the anodic electrochemiluminescence(ECL) behavior of water-soluble poly(9,9-dioctylfluorenyl-2,7-diyl)(PFO), is first studied with Na2C2O4 as coreactant using cyclic voltammetry and ECL measurements. The possible anodic ECL mechanism of PFO-C2O42- system is proposed. Based on the fact that the melamine could efficiently quenched the ECL signal of PFO-C2O42- system, a new ECL sensing for melamine was developed with a wide linear range from 9.0×10-11mol·L-1 to 1.1×10-8 mol·L-1. Furthermore, the sensor exhibited a high sensitivity and good stability. Due to the excellent ECL behavior, PFO-C2O42- system would be as a new class of promising platform for constructing ECL sensors. |
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