本研究將金奈米粒子 (gold nanoparticles，Au NPs)包覆於聚乙烯亞胺 (PEI)改質過後的帶正電之四氧化三鐵奈米粒子(Fe3O4)而形成鐵金核殼複合物(Fe3O4-Au coreshell)，並分布於聚二甲基二烯丙基氯化銨 (PDDA)改質石墨烯 (graphene)得到的GO-PDDA 上形成Fe3O4-Au@RGO 奈米複合物。Fe3O4-Au@RGO 具有光學穿透性並且能夠提升對於微生物的接觸面積進而提高表面增強拉曼光譜 (surfaceenhancedRaman scattering，SERS)偵測的靈敏度，藉由調控不同比例之Fe3O4-Au coreshell 和GO 尋找最佳拉曼增強效應並用於偵測小分子腺嘌呤 (adenine)、微生物金黃色葡萄球菌 (S. aureus)之SERS 訊號，也由於Fe3O4-Au@RGO 具有強磁性，可置於交流電高頻率磁場(high frequency magnetic field, HFMF)下產生熱能達到熱治療作用。結果顯示Fe3O4-Au@RGO 不僅擁有良好之拉曼增強效應，在熱治療方面也成功殺菌，為一多功能型奈米複合材料。

In this study, Fe3O4-Au nanohybrids were prepared by seeding gold nanoparticle (AuNPs) onto Fe3O4 nanoparticles after coating with polyethylenimine (PEI). Then Fe3O4-Au nanohybrids were attached onto cationic poly(dimethyldiallylammonium chloride) (PDDA)-modified graphene oxide (GO) sheets through in situ self-assembly behaviors, termed as Fe3O4-Au@RGO. The resulting Fe3O4-Au@RGO was
characterized systematically by transmission electron microscopy (TEM). It revealed that AuNPs were immobilized on the surface of Fe3O4, and the Fe3O4-Au nanohybrids were dispersed homogeneously on the graphene oxide layer. The surface charge and particle size of Fe3O4 would increase by PEI modification, confirmed by zetasizer measurement. The results showed that PEI and AuNPs were successfully coated on the surface of Fe3O4. Furthermore, the rapid surface-enhanced Raman scattering (SERS) detection and identification of small biomolecules (adenine) and microorganisms (gram-positive bacteria, Staphylococcus aureus) were conducted through Raman spectroscopy. Thus, it demonstrated that this nanohybrid can serve as a promising candidate for bio-applications, specifically for bio-detection. Also, the external application of a highfrequency magnetic field completely destroyed these aggregated microbes
by the magnetically induced heat. Hence, the newly developed nanohybrids were shown to be viable for physically capturing microbes and also for potential hyperthermia treatment applications.

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