Browsing by Author "Shen, Ming-Hui"

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Laser-Assisted Nanowetting: Selective Fabrication of Polymer/Gold Nanorod Arrays Using Anodic Aluminum Oxide Templates
(1970-01-01)
He, Hung-Chieh
;
Yan, Ai-Ling
;
Karapala, Vamsi Krishna
;
Wang, Shun-Fa
;
Shen, Ming-Hui
1D polymer nanomaterials have attracted significant interest in recent years because of their unique properties and promising applications in various fields. It is, however, still a challenge to fabricate polymer nanoarrays with desired sizes and controlled morphologies. Here, an unprecedented approach, the laser-assisted nanowetting (LAN) method, to selectively fabricate polymer nanoarrays is presented. Polystyrene (PS) is blended with gold nanorods (AuNRs), which are used to absorb the energy from the laser. After the blend films are brought in contact with AAO templates, the AuNRs at regions shone by the laser beams absorb the energy and heat the surrounding polymer chains, resulting in the formation of PS/AuNRs arrays in selected areas. This work paves a new research direction for developing template-based polymer nanomaterials.
Reproducible and Bendable SERS Substrates with Tailored Wettability Using Block Copolymers and Anodic Aluminum Oxide Templates
(1970-01-01)
Lin, Yu-Liang
;
Karapala, Vamsi Krishna
;
Shen, Ming-Hui
;
Chen, Yi-Fan
;
He, Hung-Chieh
Surface properties are essential for substrates exhibiting high sensitivity in surface-enhanced Raman scattering (SERS) applications. In this work, novel SERS hybrid substrates using polystyrene-block-poly(methyl methacrylate) and anodic aluminum oxide templates is presented. The hybrid substrates not only possess hierarchical porous nanostructures but also exhibit superhydrophilic surface properties with the water contact angle approximate to 0 degrees. Such surfaces play an important role in providing uniform enhanced intensities over large areas (relative standard deviation approximate to 10%); moreover, these substrates are found to be highly sensitive (limit of detection approximate to 10(-12) m for rhodamine 6G (R6G)). The results show that the hybrid SERS substrates can achieve the simultaneous detection of multicomponent mixtures of different target molecules, such as R6G, crystal violet, and methylene blue. Furthermore, the bending experiments show that about 70% of the SERS intensities are maintained after bending from approximate to 30 degrees to 150 degrees.