Browsing by Author "Yang, Cheng-Du"

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    Enhanced Plasmonic Biosensors of Hybrid Gold Nanoparticle-Graphene Oxide-Based Label-Free Immunoassay
    (2018-05-16) Chiu, Nan-Fu; Chen, Chi-Chu; Yang, Cheng-Du; Kao, Yu-Sheng; Wu, Wei-Ren
    Abstract In this study, we propose a modified gold nanoparticle-graphene oxide sheet (AuNP-GO) nanocomposite to detect two different interactions between proteins and hybrid nanocomposites for use in biomedical applications. GO sheets have high bioaffinity, which facilitates the attachment of biomolecules to carboxyl groups and has led to its use in the development of sensing mechanisms. When GO sheets are decorated with AuNPs, they introduce localized surface plasmon resonance (LSPR) in the resonance energy transfer of spectral changes. Our results suggest a promising future for AuNP-GO-based label-free immunoassays to detect disease biomarkers and rapidly diagnose infectious diseases. The results showed the detection of antiBSA in 10 ng/ml of hCG non-specific interfering protein with dynamic responses ranging from 1.45 nM to 145 fM, and a LOD of 145 fM. Considering the wide range of potential applications of GO sheets as a host material for a variety of nanoparticles, the approach developed here may be beneficial for the future integration of nanoparticles with GO nanosheets for blood sensing. The excellent anti-interference characteristics allow for the use of the biosensor in clinical analysis and point-of-care testing (POCT) diagnostics of rapid immunoassay products, and it may also be a potential tool for the measurement of biomarkers in human serum.
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    探討電化學表面電漿技術於即時監測與調控氧化石墨烯能隙之研究
    (2016) 楊承都; Yang, Cheng-Du
    表面電漿共振(surface plasmon resonance, SPR)技術可即時監測金屬-電介質表面折射率變化的特性。本研究利用SPR即時監測以電化學技術還原氧化石墨烯(Graphene oxide, GO)的去氧過程，藉由SPR角位移量的改變，判斷出不同還原時間下的氧含量，達到即時調控GO之碳氧比與能隙。 本研究採用三種不同的實驗方式還原GO，分別為實驗一：以循環伏安法(cyclic voltammetry, CV)還原GO膜；實驗二：以定電壓還原GO膜；實驗三：以CV還原GO混合溶液。前兩個實驗以胱胺(Cystamine, Cys)作為連接層，在金膜上形成穩定共價之GO膜，並分別以不同電化學模式CV與恆定電壓法進行還原。第三個實驗則是將GO溶液與NaCl電解質混合，形成GO混合溶液，之後再以CV法進行還原。 不同還原程度之GO膜，將採用X射線光電子能譜(X-ray photoelectron spectroscopy, XPS)與Raman光譜分析特性，並利用XPS的結果搭配Essential Macleod模擬軟體計算出不同還原程度之GO折射率。不同還原程度之GO混合溶液則採用光致螢光光譜(Photoluminescence, PL)與雙光束分光光譜儀系統(UV-Vis)進行分析。 本研究利用實驗與模擬結果證明了利用電化學表面電漿共振(Electrochemical surface plasmon resonance, EC-SPR)技術可以即時監測與逐步調控GO之碳氧比。使用定電壓還原在120秒內，可利用SPR技術調控GO之碳氧比，由4.10至71.41，折射率則可由1.7 + i0.17調控至1.83 + i0.42。而GO混合溶液則可用CV法調控GO之放光波長由470~600 nm。