| Chemiluminescence (CL) is a process of light generation which is initiated by the energy released in a chemical reaction. Due to the absence of external light source, CL exhibits numerous advantages, such as superior sensitivity, low detection limit and wide working range. Thus far, CL has been extensively used in chemistry, pharmacy, molecular biology, environmental science, food science and clinical medicine. In this thesis, nanoparticles-and enzyme-enhanced CL systems have been investigated. The possible mechanisms inherent in these CL systems were also demonstrated. These enhanced CL systems have been applied to enrionmental hormone, drug and protein analysis. The thesis consists of the following parts:(1) Silver nanoparticles (AgNPs) with diameter of about17±1.0nm were synthesized by sol-gel method. The incorporation of AgNPs into the luminol-KMnO4system induces sensitized effect on the CL intensity. However, further incorporation of BPA into the AgNPs-sensitized CL system results in remarkable decrease in CL intensity, thus a sensitive detection of trace BPA in water samples has been accomplished. The results indicate that in the AgNPs-luminol-KMnO4system, KMnO4can oxidize AgNPs to Ag+, which might serve as a sensitizer or co-oxidant to enhance the CL radiation. Under the optimized experimental conditions, the CL intensity was found to be proportional to the concentration of BPA ranging from1.0×10-8to5.0×10-5g L-1.The detection limit (3a) was estimated to be1×10-9g L-1. The method described herein is simple, sensitive, and has been successfully utilized for determination BPA in water samples, being in good agreement with that achievable with LC-FL method.(2) Ag NPs were capable of enhancing the CL intensity of the luminol-potassium ferricyanide system. However, incorporation of terbutaline sulfate into the AgNPs-sensitized CL system results in obvious increase in CL intensity. Thus, a flow injection method has been developed for the determination of terbutaline sulfate. Under the optimum experimental conditions, the linear range was determined to1.0×10-9～2.0×10-5g L-1(r=0.9935) and the detection limit was estimated to be1×10-10g L-1. The proposed method has been successfully utilized for the determination of terbutaline sulfate tablets with satisfactory results..(3) CdS nanoparticles (CdS NPs) of different sizes were synthesized by the citrate reduction method. The as-prepared CdS NPs were characterized by UV-vis and CL spectra. It was found that the CdS NPs could enhance the CL response of the luminol-potassium ferricyanide systemdue to the catalytic effect of the CdS NPs. On the other hand, baicalin could inhibit the CL signals of the system in alkaline solution. As a result, a flow-injection CL method has been established for assay of baicalin in pharmaceutical and human urine samples.(4) A novel and sensitive CL assay for wild-type p53protein has been demonstrated. The enhanced CL intensity was dependent on the quantity of the attached HRP molecules, which were quantitatively related to the concentration of wild-type p53protein captured by the consensus ds-oligonucleotides-covered gold plate. Under the optimal experimental conditions, the CL intensity increased linearly with the concentration of wild-type p53protein from0.01to0.5nM. The detection limit was estimated to be3.8pM. The proposed method has been successfully utilized for the assay of wild-type p53protein in normal and cancer cell lysates. The method described herein combines the specific recognition of wild-type p53protein by the consensus DNA duplexes and the catalytic activity of the incorporated enzyme toward the luminal-H2O2system, thus exhibiting higher sensitivity. The sensing protocol holds great promise for clinical diagnosis. |
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