| Summary: | 碩士 === 國立臺灣大學 === 化學研究所 === 97 === This thesis focuses on a novel gold nanodot (Au ND)-based sensor for the determination of hydrogen peroxide (H2O2) in aqueous solution and, vicariously, of glucose in serum with high sensitivity and selectivity. The fluorescence intensity of 11-mercaptoundecanoic acid-bound Au NDs (11-MUA–Au NDs) was quenched in the presence of H2O2 as a result of the oxidation of 11-MUA mediated by H2O2. The decrease in fluorescence intensity was proportional to the logarithm of the concentration of H2O2 over the range of 100 nM–1.0 mM, with a limit of detection (LOD) of 30 nM at a signal-to-noise ratio of 3. After each assay, the addition of 11-MUA restored the fluorescence; thus, the sensor system was readily regenerated. To optimize the sensitivity of the detector toward glucose, a two-step analysis assay had been developed: (i) glucose was reacted with glucose oxidase and (ii) the produced H2O2 was detected using the 11-MUA-Au ND nanosensor. This sensing system provided high selectivity (30-fold or more) for glucose over fructose, lactose, and maltose, with an LOD of 1.0 μM. Because the 11-MUA-Au ND nanosensor has a long Stokes shift (145 nm), matrix interference was minimal, allowing simple sample preparation and providing excellent linearity. This research validated the practicality of this sensing system by analyzing glucose in serum. This approach provides the practical benefits of simplicity, low cost, reproducibility, and precision.
|
|---|
