Fabrication of Two- and Three-Dimensional Structures of Nanoparticles Using LB Method and DNA Hybridization
- PDF / 1,397,254 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 55 Downloads / 174 Views
FABRICATION OF TWO- AND THREE-DIMENSIONAL STRUCTURES OF NANOPARTICLES USING LB METHOD AND DNA HYBRIDIZATION Takayuki Takahagi, Shujuan Huang, Gen Tsutsui, Hiroyuki Sakaue, and Shoso Shingubara Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan ABSTRACT In this paper we describe fabrication methods for two types of nanostructures, two- and three-dimensional arrays of gold nanoparticles. Large-scale and high-ordered monolayers of alkanethiol-encapsulated gold particles were fabricated by using Langmuir-Blodgett (LB) method. Three-dimensional nanoparticle arrays composed of gold nanoparticles of two different sizes, which were encapsulated by complementary thiol-capped DNA oligonucleotides, were fabricated by using DNA hybridization. DNA hybridization occurred upon mixing these particles, which resulted in the assembly of three-dimensional nanostructure of gold particles. Scanning electron microscopy observations and UV spectroscopy measurement were performed to confirm the construction of the nanostructures. INTRODUCTION Recently, nanostructured materials made of nanoparticles have attracted much research attention for the novel electrical, optical, magnetic, and chemical properties [1-4]. The construction of nanoparticles in an ordered structure is the key issue for their potential application in nanoelectronics devices and magnetic storages. In our previous work [5], we developed a self-organization method for fabricating a planar ordered array of gold particles encapsulated by alkanethiol. We have observed the Coulomb blockade phenomena in the nanostructures consisting of the encapsulated gold particles of 9 nm in diameter [6], which suggests that alkanethiol monolayer surrounding the gold particles can serve as a stable tunnel barrier and the proposed nanostructure is very useful for developing nanoelectronics devices. In this paper, we report the fabrication of a large-scale highly ordered monolayer of gold particles by using LB method. In addition, in order to fabricate more complex nanostructures, one feasible way is DNA-assisted fabrication. DNA oligonucleotides have hybridization information encoded in their sequence. In this study, by utilizing this property of DNA, we fabricated a three-dimensional structure of gold nanoparticles with two particle sizes, which were encapsulated by complementary DNA oligonucleotides. Scanning electron microscopy (SEM) observations and UV spectroscopy measurement were carried out to confirm the construction of the nanostructures. EXPERIMENT LB preparation for gold nanoparticle monolayers The gold particles used in this work were synthesized by using a mixture of trisodium citrate and tannic acid for the reduction of chloroauric acid (HAuCl4) [7]. It is reported that gold AA4.5.1/W4.5.1
particles synthesized by this method is homodispersed. The size of the particles is determined by the quantity of the tannic acid in the reducing solution. Because alkanethiols are water insoluble, the aqueous gold colloid
Data Loading...
