Browsing by Author "Lee, Yun-Han"

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Immunoassays for the cancer biomarker CA125 based on a large-birefringence nematic liquid-crystal mixture
(2015-01-01)
Sun, Shih-Hung
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Lee, Mon-Juan
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Lee, Yun-Han
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Lee, Wei
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Song, Xiaolong
The use of fluorescence is ubiquitously found in the detection of immunoreaction; though with good sensitivity, this technique requires labeling as well as other time-consuming steps to perform the measurement. An alternative approach involving liquid crystals (LCs) was proposed, based on the fact that an immunocomplex can disturb the orientation of LCs, leading to an optical texture different from the case when only antigen or antibody exists. This method is label-free, easy to manipulate and lowcost. However, its sensitivity was low for practical usage. In this study, we adopted a high-birefringence liquid crystal (LC) to enhance the sensitivity for the immunodetection. Experiments were performed, targeting at the cancer biomarker CA125. We showed that the larger birefringence (Delta n = 0.33 at 20 degrees C) amplifies the detected signal and, in turn, dramatically improves the detection limit. To avoid signal loss from conventional rinsing steps in immunodetection, CA125 antigen and antibody were reacted before immobilized on substrates. We studied the specific binding events and obtained a detection limit as low as 1 ng/ml. The valid temperature ranges were compared by using the typical single-compound LC 5CB and the high-birefringence LC mixture. We further investigated time dependency of the optical textures and affirmed the capability of LC-based immunodetection in distinguishing between specific and nonspecific antibodies.
Label-free immunodetection of the cancer biomarker CA125 using high-Delta n liquid crystals
(2014-07-01)
Su, Hui-Wen
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Lee, Yun-Han
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Lee, Mon-Juan
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Hsu, Yi-Chiang
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Lee, Wei
A label-free and array-based optical liquid-crystal (LC) immunodetection technique for the detection of CA125 antigen, a protein biomarker most frequently used for ovarian cancer detection, was demonstrated with a nematic LC with larger birefringence (Delta n) to promote sensitivity in detecting biomolecules. The LC-based immunodetection offers an alternative and sensitive approach for the detection of biomarker proteins, with the potential of replacing conventional immunoassays used in biochemical studies and clinical laboratories. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License.
Low-Power Displays With Dye-Doped Bistable Chiral-Tilted Homeotropic Nematic Liquid Crystals
(2014-12-01)
Lee, Yun-Han
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Huang, Kuan-Chung
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Lee, Wei
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Chen, Chao-Yuan
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光電系統研究所
Energy-efficient display has been drawing much attention in recent years due to the prevailing of mobile devices as well as the rising environmental concerns. A chiral nematic system with appropriately configured pre-tilted angle and pitch length is capable of switching between the twist-like and homeotropic-like states with the merit of bistability. Introducing dichroic dyes into this system, we demonstrated a bistable scheme of liquid-crystal display without the need of polarizers.
Quantum Dots Enhanced Liquid Displays
(2014-12-01)
Luo, Zhenyue
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Xu, Su
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Gao, Yating
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Lee, Yun-Han
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Liu, Yifan
Two types of dielectrophoretic liquid displays with patterned quantum dots (QDs) array for enhancing the color performance are demonstrated. QDs not only provide vivid color (similar to 136% AdobeRGB in CIE1976 color space) but also greatly improve light efficiency by reducing the optical loss from color filters. These polarizer-free liquid displays offer vivid colors, high transmittance, wide viewing angle, and modest response time and contrast ratio. They are promising candidates for E-book and mobile display applications.
Reflective Displays Based on Dye-Doped Bistable Chiral-Tilted Homeotropic Nematics
(2015-08-13)
Huang, Kuan-Chung
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Lee, Yun-Han
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Lee, Wei
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影像與生醫光電研究所
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Institute of Imaging and Biomedical Photonics