| Summary: | 博士 === 國立清華大學 === 生醫工程與環境科學系 === 98 === Nanoscience possesses advantageous properties owing to their small size and large surface area. The aim of green chemistry is to reduce waste and hazard in chemical products and process. The potential benefits of merging cross disciplines have been realized and produce innovative techniques in recent years. Herein, we prepared novel magnetic nanoparticles (MNPs) and their nanocomposites, which were applied to analyze trace multiple heavy metals and volatile organic compounds (VOCs), demonstrating successful coupling of green analytical chemistry and nanoscience. For heavy metals analysis (Chapter 2), a hyphenated system consisting of a lab-on-valve system integrated with a micro-column packed with magnetic nano-adsorbent (MNPs-PAA) for on-line pre-treatment followed by ICPMS determination was designed and built. The accuracy was evaluated by analyzing certified reference materials of SRM 2670a (trace elements in urine, low level) and CASS-2 (nearshore seawater reference material for trace metals). Good agreement between the measured and certified values demonstrates that the system is useful for trace analysis of multiple heavy metals in environmental and biological aqueous samples. In conjunction with the reduced use of solvent and the greenness of preparing MNPs-PAA adsorbent makes the proposed method a green analytical chemistry method. For VOCs analysis (Chapter 3), a magnetic nanocomposite (MCNT) consisting of MNPs and multi-walled carbon nanotubes (MWCNTs) was prepared based on their electrostatic interactions. The MCNT integrates the advantages of controllable immobilization provided by MNP’s superparamagnetism and excellent adsorption property provided by the large specific surface area of MWCNTs, rendering it being a preferred gas adsorbent of VOCs followed by TD/GC-MS determination. The lower detection limit by MCNT adsorbent demonstrated its potential use in green analytical chemistry. A wide range of nanomaterials with different types and properties has been examined for their potential use in various applications. The inevitable questions regarding the nanotechnology risk to the environment and human health were highly concerned. Using zinc oxide nanoparticles (ZnO NPs, Chapter 4) as an example, an integrated analytical platform for cytotoxicity assessment was proposed based on the material characterization, in vitro toxicological assessment, and chemical analysis. Elevated levels of dissolved 64Zn from ZnO NPs and variation of intracellular 39K/40Ca were observed in ZnO NPs treated HaCaT cells, indicating that the dissolving behavior of ZnO NPs played an important role in inducing cytotoxicity. The isotope-labeled 68ZnO NPs possess similar trend as ZnO NPs, demonstrating its potential use as tracer in nanotoxicological study of ZnO NPs.
Green nanoscience practice is readily realized via successful integration of green synthesis and green analytical chemistry as demonstrated by the preparation and applications of MNPs and its nanocomposites reported in this thesis. The integration of material characterization, in vitro toxicological assessment, and chemical analysis for nanotoxicology risk assessment as demonstrated by the cytotoxicity study of ZnO NPs might help clarify the doubt about nanotechnology. The platform proposed is potentially useful for future design and synthesis of nanomaterials with lower nanotoxicity, a step forward toward the aim of green nanoscience.
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