Lead ion and HbA1c detections with purple membrane-based photoelectric chips
| Autor: | Jr-Wen Cheng, 鄭智文 |
|---|---|
| Rok vydání: | 2018 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 106 Purple membrane (PM) is one of the cellular membranes of archaeon Halobacterium salinarum, containing bacteriorhodopsin (BR), a light-driven proton pump capable of transporting a proton across PM upon illumination and subsequently generating photocurrents. Based on the linear dependence of BR photocurrents on illumination intensities, we had developed series of PM-based biosensor. This study contains two parts. First, based on light scattering of gold nanoparticle (AuNPs), a PM chip sequentially coated with DNAzyme and AuNPs-conjugated substrate oligo was used as the recognition element to detect lead ion (Pb2+). Chip fabrication and Pb2+ detection were both optimally investigated and confirmed by both Raman spectroscopy and PM-photocurrent measurement. The recovery of the photocurrent density linearly depended on Pb2+ concentrations, with the highest photocurrent density recovery (97 %) observed at 1 μM Pb2+ of the PM-based sensor chip. The Pb2+ sensor chip had a good selectivity and completed the detection in 15 min, with a detection limit of 1 nM (0.208 μg/mL), which was much lower than the regulation concentration (10 μg/mL). Secondly, we continued our previous hemoglobin (Hb) and glycated hemoglobin (HbA1c) studies with the developed Hb aptamer-PM and HbA1c aptamer-PM chips. By optimizing the fabrication process, the sensitives of both chips increased. In addition, the use of a proper additive speeded up detection, shorten the detection from 2 hr to 15 min. Finally, the stability studies revealed both PM and Hb aptamer-PM chips maintained their activities for at least one month, suggesting their potentials in future commercial applications. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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