| Summary: | 博士 === 國立清華大學 === 化學工程學系 === 101 === The study aims at the development of the heavy metal ion sensors and the non-enzymatic glucose sensor consisting of binary materials due to the growing concerns about the environmental pollution and the health care issue, respectively.
In the first part of the study for heavy metal ion sensors, we developed the bismuth film electrodes (BFEs) for the detection of Sn2+. The preferred orientation ratio (f) of the deposited bismuth was found to be a key factor determining the Sn2+-sensing ability of BFEs. Especially when f is above 0.11, the synergistic effect from the grain size and the f value on the sensing ability for Sn2+ can be observed. Since the fractional factorial design (FFD) of experiments indicate that the deposition pH value and the temperature affect the f of the deposited bismuth, the f was controlled from 0.09 to 1.09 by adjusting these two factors to establish the relationship between the preferred orientation of the deposited bismuth and the sensing ability for Sn2+.
The second heavy metal ion sensor utilized Nafion-modified (graphene/carbon nanotube) composite to deposit with Bi on the screen printed electrodes (SPEs) for detecting trace amount of Pb2+. The preliminary test shows that the Pb2+-sensing ability for Nafion-(G/CNT)-BiSPE was 50-times higher than that of BiSPE. The FFD study revealed that the key factors determining the sensing ability are the deposition pH value and the concentration of Nafion. The steepest ascent pathway (SAP) study further established that the highest sensing ability for Pb2+ can be achieved when utilizing 0.3% Nafion and the stripping buffer solution with the pH equals to 4.75. Finally, the sensitivity and the sensing current obtained under the optimal conditions for SPE, Bi/SPE, Bi/Nafion/SPE, Bi/G-CNT/SPE, and Bi/Nafion/G-CNT/SPE were compared by the results from sqaure wave anodic stripping voltammetry (SWASV).
In the last part, we introduced a novel non-enzymatic glucose sensor via the cathodic deposition of nickel-cobalt hydroxide (denoted as (Ni-Co)(OH)2) on the screen-printed carbon electrodes (SPCEs). Due to the atomic-scale mixing of Ni and Co ions, (Ni-Co)(OH)2 demonstrates the more significant signal and the less positive detecting potential for glucose oxidation compared with Co(OH)2 and Ni(OH)2, respectively. The detection sensitivity for glucose is 122.45 uA mM−1 cm−2 (R2 = 0.989) in the linear detection range up to 3700 uM. In addition, low interference responses from 25 uM ascobic acid (AA), uric acid (UA), and dopamine (DA) were obtained, which were 10.76 %, 14.29 %, and 1.41 % of the detection signal from 0.2 mM glucose, respectively. Consequetly, the non-enzymatic glucose sensor exhibits the low detecting potential, the wide linear detection range, and the high signal-to-noise ratio.
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