Biosensors and Bioelectronics 27 (2011) 183–186 Contents lists available at ScienceDirect Biosensors and Bioelectronics j our na l ho me page: www.elsevier.com/locate/bios Short communication A three-dimensional gold nanodendrite network porous structure and its application for an electrochemical sensing Tran Ngoc Huan a , Thothadri Ganesh a , Kwang Soo Kim b , Saetbyeol Kim a , Sung-Hwan Han a , Hoeil Chung a,∗ a Department of Chemistry, Research Institute for Convergence of Basic sciences, Hanyang University, Seongdong-Gu, Haengdang-Dong, Seoul 133-791, Republic of Korea b Samsung Electro-Mechanics, Suwon, Republic of Korea a r t i c l e i n f o Article history: Received 20 April 2011 Received in revised form 6 June 2011 Accepted 10 June 2011 Available online 17 June 2011 Keywords: Gold nanodendrite Nanodendrite network porous structure Nucleation Arsenic detection a b s t r a c t A three dimensional (3D) gold (Au) nanodendrite network porous structure constructed by a sim- ple electrochemical synthetic method has been presented, and its utility for sensitive electrochemical measurement was demonstrated in this study. The 3D nanodendrite network porous structure was con- structed on a platinum surface through electrodeposition of Au under the presence of hydrogen bubbles generated from the same surface. Iodide, used as a co-reagent, played an important role in the con- struction of the nanodendrite network by preventing continual growth of Au into larger agglomerates as well as inhibiting coalescence of neighboring nanodendrites. An electrochemical sensor incorporating the structure was built and used to detect As(III) in ultra low concentration range. For the purpose of comparison, bare gold and gold nanoparticle-incorporated electrodes were also prepared. With the use of 3D nanodendrite network porous structure, a much more sensitive detection of As(III) was possible due to its large surface area. © 2011 Elsevier B.V. All rights reserved. 1. Introduction The design and synthesis of nano-structures on electrode surface have been recently studied to improve sensitivity of elec- trochemical measurement by increasing surface area for analysis (Juste et al., 2005; Guo and Wang, 2007). The incorporation of nano-structures, such as nanoparticles, nanorods, nanotubes and nanodendrites, onto electrode surface has been largely consid- ered for diverse analytical applications. Among them, gold (Au) nanodendrites have drawn a great attention due to availability of large surface area within a structure. Until now, to build nan- odendrite structure, either chemical synthesis or electrochemical synthesis has been demonstrated. Chemical synthesis of Au nan- odendrite mostly involves the reduction of Au salt or chloroauric acid in aqueous solutions in the presence of diverse reducing agents such as 3,4-ethylenedioxythiophene (EDOT) (Lu et al., 2007), hydroxylamine (NH 2 OH) (Jasuja and Berry, 2009), a zinc plate and 1-butyl-3 methylimidazolium hexafluorophosphate [BMIM][PF 6 ] (Qin et al., 2008), and a mixture of dodecyltrimethylammonium bromide (DTAB) and -cyclodextrin (-CD) (Huang et al., 2010). In these reactions, Au nanodendrite structure is formed through the continual nucleation of Au. However, the construction of nanoden- ∗ Corresponding author. Tel.: +82 2 2220 0937; fax: +82 2 2299 0762. E-mail address: hoeil@hanyang.ac.kr (H. Chung). drite structures through chemical reactions requires long period of time and extensive use of chemicals. In comparison with chem- ical synthesis, electrochemical synthesis of Au dendrite is much faster and simpler without extensive use of reagents. Very recently, 2 different electrochemical strategies based on the electrodeposi- tion of Au directly to the surface of electrode have been reported. First, the structure was built by applying solely negative poten- tial, and applied for a DNA biosensor (Xu et al., 2010; Li et al., 2011). Second, the reduction of Au was performed under presence of cysteine (Lin et al., 2011). Adsorption of cysteine on Au helped to construct a nanodendrite structure. So far, the demonstrated nanodendrites constructed by either chemical or electrochemical synthetic ways are mostly two dimensional (2D) structures, formed in several localized areas or spread on a surface. To substantially increase surface area available for electrochemical measurements, rather than 2D structures, a three dimensional (3D) structure in which each nanodendrite is networked together will be highly ben- eficial. This useful nanodendrite-networked 3D structure has not been demonstrated so far. In this article, we present a novel 3D Au nanodendrite network structure prepared by a simple and fast electrochemical synthesis. The basic strategy for synthesis of the structure was the combi- nation of 2 simultaneously occurring electrochemical reactions: electrodeposition of Au onto a platinum surface in presence of iodide as a co-reagent to drive continual generation of nanoden- drites and the simultaneous release of a hydrogen bubble at the 0956-5663/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.bios.2011.06.011