Browsing by Author "Zhou, Gang-Yan"

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Label-free detection of DNA hybridization using nanopillar arrays based optical biosensor
(2014-04-01)
Chen, Jem-Kun
;
Zhou, Gang-Yan
;
Chang, Chi-Jung
;
Cheng, Chih-Chia
;
應用化學系
In this study we fabricated nanopillar arrays (NPLAs) of silicon, through a process involving very-large-scale integration and reactive ion etching, for use as two-dimensional periodic relief gratings on silicon surfaces. Oligonucleotides were successively immobilized on the pillar surface, allowing the system to be used as an optical detector specific for the targeted single-stranded DNAs (ssDNAs). The surfaces of the oligonucleotides-modified NPLAs underwent insignificant structural changes, but upon hybridizing with target ssDNA, the NPLAs underwent dramatic changes in terms of their pillar scale. Binding of the oligonucleotides to the NPLA occurred in a way that allowed them to retain their function and selectively bind the target ssDNA. We evaluated the performance of the sensor by capturing the target ssDNA on the NPLA and measuring the effective refractive index (n(eff)). The binding of the target ssDNA species to the NPLA resulted in a color change from pure blue to red, observable by the naked eye at an angle of 15 degrees. Moreover, we used effective medium theory to calculate the filling factors inside the NPLA and, thereby, examine the values of n(eff) during the structural changes of the NPLA. Accordingly, these new films have potential applications as label-free optical biosensors. (C) 2013 Elsevier B. V. All rights reserved.
Using nanopillars of silicon oxide as a versatile platform for visualizing a selective immunosorbent
(2013-06-24)
Chen, Jem-Kun
;
Zhou, Gang-Yan
;
Huang, Chih-Feng
;
Ko, Fu-Hsiang
;
應用化學系
In this study, we fabricated nanopillar arrays of silicon oxide for use as two-dimensional periodic relief gratings (2DPRGs) on Si surfaces. We deposited antibodies onto the pillar surfaces of 2DPRGs modified with protein G to obtain optical detectors that were specific for the targeted antigen; the antigen units that filled the spaces between the nanopillars of the 2DPRG lead to a dramatic change in the pillar scale. The effective refractive index (n(eff)) of the 2DPRGs was related to the pillar scale of the 2DPRG; after coupling of the antigen, a color change from pure green to orange was observable. (C) 2013 AIP Publishing LLC.