| Nanotechnology, one of the critical technologies of the 21st century, is multidisciplinary and interdisciplinary and covers diverse fields including chemistry, physics, materials science, engineering, biology and even medicine. Over the past decade, functionalized gold nanoparticles (AuNPs) have attracted great interest in biomolecular detection and clinical diagnostic application because of their facile synthesis and surface modification, strongly catalytic properties and excellent candidate for bioconjugation.Capillary electrophoresis (CE) is a highly efficient means of separation, which is performed in capillary tube and driven by electric field. It brings a profound revolution following the gas chromatography (GC) and high-performance liquid chromatography (HPLC). CE is an established microseparation technique, which provides advantages in terms of high separation efficiency, short analysis time and low cost.Chemiluminescence immunoassay (CL-IA) has been well established for the quantitation of low concentration analytes in complex biosamples and has been widely used in the research of clinical diagnosis. CE-based CL-IA that combines high separation efficiency of CE, high sensitivity of CL and the high specificity of IA has been proved to be a promising technique for complex biological compound assays and diagnostic clinical analysis.In this work, CE-based CL-IA method has been developed using AuNPs as a protein label reagent. The main investigations are as follows.1. A sensitive CE-based CL-IA method has been developed for the first time by taking advantage of the catalytic feature of AuNPs as CL label. The AuNPs could catalyze the reaction between luminol and hydrogen peroxide, accompanied by light emission. After the non-competitive immunoreactions, the free antibody and the immunocomplex were well separated by CE and detected by CL in 5 min under the optimal conditions. It was developed using the human immunoglobulin G (hIgG) as analyte. By the established method, the calibration curve of hIgG is in the range of 0.008-5μg/mL with a correlation coefficient of 0.9950 and the detection limit is 1.14×10-3 μg/mL (S/N=3). The assay was applied to hIgG determination in spiked samples of human serum with recoveries between 85.0 and 107.0%. The method was successfully used for the quantification of hIgG in sera of patients.2. The CL reaction of luminol-H2O2 system could be strongly enhanced in the presence of norfloxacin and ciprofloxacin. Based on this phenomenon, a new approach of simultaneous detection for norfloxacin and ciprofloxacin by CE coupling with CL was built for the first time. The effects of CE separation and CL detection conditions were studied in detail. The baseline separation of norfloxacin and ciprofloxacin was obtained within 4.5 min under the optimum conditions. The limits of detection (S/N=3) of norfloxacin and ciprofloxacin were 2.9×10-10 and 1.1×10-12mol/L, respectively. The limits of quantitation (S/N=10) of norfloxacin and ciprofloxacin in human urine samples were 6.0×10-8 and 5.1×10-10 mol/L, respectively. The maximum intra- and inter-day relative standard deviations of migration time and peak area of norfloxacin and ciprofloxacin were less than 3.6% and 6.3%(n=6), respectively. The recoveries of two analytes at different spiked concentration levels in human urine are between 91.0% and 112.7%. The proposed method was successfully applied to analysis of norfloxacin and ciprofloxacin in human urine sample and the monitoring of pharmacokinetics of ciprofloxacin in human body.
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