Fabrication of functional micro- and nanoneedle electrodes using a carbon nanotube template and electrodeposition
- PDF / 2,018,899 Bytes
- 6 Pages / 595.276 x 793.701 pts Page_size
- 2 Downloads / 203 Views
NANO EXPRESS
Open Access
Fabrication of functional micro- and nanoneedle electrodes using a carbon nanotube template and electrodeposition Taechang An1, WooSeok Choi1, Eunjoo Lee2, In-tae Kim1, Wonkyu Moon1 and Geunbae Lim1,3*
Abstract Carbon nanotube (CNT) is an attractive material for needle-like conducting electrodes because it has high electrical conductivity and mechanical strength. However, CNTs cannot provide the desired properties in certain applications. To obtain micro- and nanoneedles having the desired properties, it is necessary to fabricate functional needles using various other materials. In this study, functional micro- and nanoneedle electrodes were fabricated using a tungsten tip and an atomic force microscope probe with a CNT needle template and electrodeposition. To prepare the conductive needle templates, a single-wall nanotube nanoneedle was attached onto the conductive tip using dielectrophoresis and surface tension. Through electrodeposition, Au, Ni, and polypyrrole were each coated successfully onto CNT nanoneedle electrodes to obtain the desired properties. Introduction With the development of nanotechnology, the demand for information about microscale systems has increased [1,2]. Micro- and nanoneedle electrodes provide opportunities for electrochemical and biological studies of microenvironments, such as scanning electrochemical microscopy (SECM) [3-5] and single-cell analysis [6-8]. For example, a nanoneedle with a high aspect ratio and small diameter can be used as both an injection [9] and manipulation tool [6,10] for biomolecules and nanoparticles in a living cell. A nanoneedle with a functional surface, such as metal oxide, can be used as an intracellular sensor to monitor an intracellular environment [11]. Furthermore, a nanoneedle electrode coated with an insulation layer can be used as an SECM probe to measure electrochemical reactions of micro- and nanoenvironments [3,12]. To be used in various applications, a nanoneedle surface must be modified to the desired functional surface. Two methods are used to functionalize nanoneedles: direct functionalization of the nanoneedle bare surface, and functionalization of a nanoneedle surface coated with other materials [13]. Because the bare surface of * Correspondence: [email protected] 1 Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Korea. Full list of author information is available at the end of the article
nanoneedle materials provides only limited chemical functional groups, complex chemical and physical treatments are often used to obtain the desired surface properties. On the other hand, the surface coating method not only affords the desired functional surface, but also improves the mechanical properties of the nanoneedles. Although many nanoneedle fabrication methods have been reported, these methods have material limitations because most nanoneedles are fabricated using carbon nanotubes (CNTs) [7,14,15] and silicon [6,16]. Therefore, it is necessary to fabricate nano
Data Loading...
