Development of ultrasensitive biosensor using single-crystalline gold nanowire and gold nanoplate = 단결정 금 나노선 및 금 나노판을 이용한 초고감도 바이오센서의 개발

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Au nanostructures are the most commonly used metal materials due to their biocompatibility and easy-to-modification properties. We synthesized ultraclean and ultraflat single-crystalline Au nanostructures without surfactants and catalyst using vapor transport method in furnace system. Au nanowire (NW) and Au nanoplate (NPL)-based biosensors are applied for the detection of various biomolecules including pathogens, heavy metals, radioactive-species and intractable disease biomarkers. By further developing these applications, we fabricated the ultra-sensitive and ultra-selective Au nanostructures-based biosensors to detect glucose as diabetes-monitoring marker and diverse cancer biomarkers such as gastric cancer, breast cancer and ovarian cancer. In chapter 2, we report nanogap-rich Au NW surface-enhanced Raman scattering (SERS) sensor for the detection of telomerase activity. Nanogap-rich Au NW was prepared by sputtering Au atoms at the surface of Au NW for 210 s. By varying the sputtering time, nanogap-rich Au NW exhibited the maximized SERS signals and the high reproducibility with 4.80 % of the relative standard deviations. Au nanoparticles were uniformly and densely deposited on the whole Au NW. This sensor can detect telomerase activity down to 0.2 cells/mL due to its high sensitivity and reproducibility. Importantly, nanogap-rich Au NW sensor can detect the high telomerase activity in gastric and breast cancer tissues excised from 16 tumor-bearing mice, which demonstrates that this sensor diagnosis of gastric and breast cancers. In chapter 3, we present Au NPL-Au NP SERS sensor for the sensitive and selective detection of ovarian cancer biomarker, human epididymis protein 4 (HE4). By analyzing the SERS signals and the number of NPs measured from SEM images at various HE4 concentrations, we found that this sensor could detect HE4 antigens down to $10^{-17} M$ (10 aM). Moreover, our Au NPL-Au NP SERS sensor exhibits high SERS signals in HE4 samples while SERS signals are hardly showed in BSA, CRP and CYFRA 21-1 samples. The antigen binding sites are fully exposed by well-oriented antibodies on the ultraclean and ultraflat surface of Au NPL, which is minimized the non-specific binding and background signals. Therefore, we anticipate that Au NPL-Au NP sensor can be applied in early diagnosis of ovarian cancer by measuring HE4 antigen. In chapter 4, we report ordered intermetallic Au-Cu NW electrode for the selective detection of glucose against ascorbic acid (AA). We synthesized Au₃Cu and AuCu₃ NW by modifying the position of Au NW-grown sapphire substrates. To investigate the electrocatalytic performance of Au, Au₃Cu and AuCu₃ NW, we fabricated the single NW electrodes and detected glucose. In Au NW electrode, the selective detection of glucose is not possible because the oxidation peak of glucose overlaps with that of AA. However, Au₃Cu NW electrode exhibits the additional current wave at - 0.16 V for the detection of glucose, which is not showed for the detection of AA. More importantly, this Au₃Cu NW electrode can selectively detect glucose even in the mixture of glucose and AA. Therefore, Au₃Cu NW electrode can be used in the selective detection of glucose without the interfering effect of AA. Single-crystalline Au NW and Au NPL can be usefully applied in the cancer diagnosis and diabetes monitoring fields. Further, we anticipated that theses sensors can be used as valuable sensors in biomedical fields.
Advisors
Jung, Yong Wonresearcher정용원researcher
Description
한국과학기술원 :화학과,
Publisher
한국과학기술원
Issue Date
2018
Identifier
325007
Language
eng
Description

학위논문(박사) - 한국과학기술원 : 화학과, 2018.2,[vii, 101 p. :]

Keywords

Single-crystalline▼agold nanowire▼agold nanoplate▼abiosensor; 단결정▼a금 나노선▼a금 나노판▼a바이오센서

URI
http://hdl.handle.net/10203/265506
Link
http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=734511&flag=dissertation
Appears in Collection
CH-Theses_Ph.D.(박사논문)
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