| Summary: | 碩士 === 國立臺北科技大學 === 化學工程研究所 === 102 === Part 1
Hybridization of poly(luminol) (PLM) and poly(neutral red) (PNR) has been successfully performed and further enhanced by a conductive and steric hybrid nanotemplate using graphene oxide (GO) and multi-walled carbon nanotubes (MWCNT). Morphology of PLM-PNR-MWCNT-GO mycelium-like nanocomposite is studied by SEM and AFM and it is electroactive, pH-dependent, and stable in the electrochemical system. It shows eletrocatalytic activity to NADH with high current response and low overpotential. By amperometry, it shows a high sensitivity of 288.9 μA mM-1 cm-2 to NADH (Eapp. = +0.1 V). Linearity is estimated in a concentration range of 1.33×10-8 – 1.95×10-4 M with a detection limit of 1.33×10-8 M (S/N = 3). Particularly, it also shows another linear range of 2.08×10-4 – 5.81×10-4 M with a sensitivity of 151.3 μA mM-1 cm-2. Hybridization and activity of PLM and PNR can be effectively enhanced by MWCNT and GO, performing an active hybrid nanocomposite for determination of NADH.
Part 2
This study presents a simple electrochemical approach for preparing the graphene oxide (GO)/multiwalled carbon nanotubes (MWCNTs) composite by homogenous dispersion of MWCNTs and GO, which responds sensitively for the electrochemical determination of pyrazinamide (PZM). The surface morphological results by transmission electron microscope (TEM) confirmed that MWCNTs were wrapped with GO sheets. The MWCNTs/GO composite showed superior electrocatalytic activity towards the reduction of PZM when compared with either pristine MWCNTs or GO. The major reason for the efficient simultaneous detection at nanocomposite was the synergistic effect between MWCNTs and GO. The electrochemical reduction of PZM was investigated by cyclic voltammetry and differential pulse voltammetry. The response of PZM is linear over the concentration range from 37.5 – 1800 μM, with the detection limit (S/N = 3) of 5.54 μM and the sensitivity was found to be 38 μA mM -1 cm -2. The proposed sensor exhibits good sensitivity, selectivity and has shown potential for the detection of PZM in real samples with appreciable consistency and precision. In addition, the proposed electrochemical sensor showed good results towards the commercial pharmaceutical formulated PZM samples.
Part 3
The preparation of nanostructured metal particles provides an environmentally friendly option, as compared to currently available chemical and/or physical methods. Here we have biosynthesized silver nanoparticles (AgNPs) from plant extracts. In this work, a single-step low-temperature biosynthetic route for producing AgNPs using Eucalyptus (Eucalyptus globulus) extract. Stable AgNPs were formed by treating solution using the plant extracts as reducing agents. These nanoparticles were analyzed by various characterization techniques to reveal their morphology, chemical composition, and bioactivity. Nanostructure size, crystal nature, purity and morphologies were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM), Gas chromatography–mass spectrometry (GC/MS), X-ray diffraction (XRD) and Cyclic voltammetry (CVs). The particle size ranging from 100 to 500 nm and the shape of the plate and spherical structures could be controlled by changing the reaction temperature and leaf broth concentration. The concentrations of leaves extract and metal ion are playing an important role in the biosynthesis of AgNPs. More elaborate studies are required to elucidate the mechanism of biological nanoparticles synthesis. This simple, low cost and greener method for development of AgNPs may be valuable in environmental, biotechnological and biomedical applications.
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