| Summary: | 碩士 === 國立清華大學 === 生物醫學工程研究所 === 104 === In this study, we demonstrate that polymers and metal substrates can be coated metal nanoparticles [i.e., gold nanoparticles (Au NPs), silver nanoparticles (Ag NPs), hollow gold nanoparticles (HGNs)] can be immobilized onto polymer and metal substrates via self-assembly.The substrates functionalized with metal nanoparticles can be applied to biomedical engineering and detection of food safety. In previous studies, some methods have been developed to immobilize metal nanoparticles onto substrates, which typically need expensive equipments, complicated procedures, and restricted types of material.In first part of my thesis, we demonstrate that monolayer metal nanoparticles array can be homogenously immobilized onto polymer and metal substrates via the wet-chemical method, and systematically discuss the mechanism of self-assembly. Next, we utilized the functionalized substrates to develop two applications using the chemical and optical properties of metal nanoparticles. In the second part, we immobilized Ag NPs onto implantable devices hasing a polymer or metal surface, and found the nanoparticles coating presented efficient anti-biofilm activity against E.coli, P.sudomonas, S.aureus. More importantly the nanoparticle-coated substrates show negligible cytotoxicity toward NIH-3T3 cell. In the third part, the amount of the biogenic amines has been proved to be associated with corruption of seafood. Therefore, we used a low-cost, dispsable, polyethylene terephthalate (PET) substrates to develop a colorimetric sensor for the detection of biogenic amines. The PET-based sensors display the optical changes upon increasing putrescine concentration, which was attributed to the red-shift of surface plasmon resonance (SPR) absorption peak of metal nanoparticles. In order to verify the concept, we spiked various concentrations of putrescine in fresh salmon samples purchased from the local market. Visible color change was observed in the silver nanoparticles (AgNPs) biosensor by the naked-eye within 15 seconds, with a limit of detection (LOD) of 43 ppm. The gold and hollow gold nanoparticles (AuHGN) biosensor showed obvious spectral peak shifts, with its LOD as low as 3 ppm. Both biosensors demonstrated LODs well below the European Commission’s recommended concentration of 300 ppm and provided a biosensing platform for the low-cost and simple detection of biogenic amines. Finally, we demonstrate that the food freshness could be in situ monitored by naked eyes by using our PET-based sensors.
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