Current-Voltage Characterization on Au-DNA-Au Junctions under the Influence of Magnetic Field Nadia Mahmoudi Khatir, Seyedeh Maryam Banihashemian, Vengadesh Periasamy * , Wan Haliza Abd Majid, Saadah Abdul Rahman Low Dimensional Material Research Centre, Department of Physics, University of Malaya, Kuala Lumpur Email, vengadeshp@um.edu.my ∗ Author to whom correspondence should be addressed; E-Mail: vengadeshp@um.edu.my, Tel: +60379674038, Fax: +60379674146 Keywords: DNA sensor; I-V curve; magnetic sensor Abstract. We utilized Deoxyribonucleic acid (DNA) strands immobilized between a metal gap and its behavior was investigated. The DNA strands were initially prepared using the PCR method while gaps of 10.00 µm lengths were created on gold layer deposited onto silicon substrate. Once immobilized, current-voltage characterization was carried out on the Au-DNA-Au structure fabricated under the presence and absence of magnetic field. Experimental results clearly highlight the behavior of the DNA strands similar to semiconductor materials. An exponential decrease observed in the current in presence of external magnetic field suggests possible future application as a magnetic sensor. Introduction The study of the electronic behavior of organic compounds has led to important research on characterization of the electronic properties of biological materials. Since deoxyribonucleic acid (DNA) is arguably the most significant molecule in nature, I has been studied extensively as an important material for molecular electronic applications [1]. Charge transport mechanism in DNA is being investigated in view of its biological implications in damage and repair, protein bonding, and envisioned integration in future bioelectronics or DNA-based chips. The electron transport phenomena of DNA changes with the base sequence, counter ion type (buffer type) and relative humidity (measurement environment, i.e. whether in the atmosphere or in a vacuum). It also depends on the sample shape and measurement method. In particular, when fixed electrodes on an insulating substrate are used, the gap length between the electrodes is a critical factor [2]. The first direct electrical transport measurement on a single, 16-µm-long λ-DNA, was published in 1998 by Braun et al. Later on, in 1999 Fink et al. [3] reported ohmic behavior in λ-DNA molecules with a resistance in the MΩ range. Further experiment published in 2000 by Porath et al. [4] measured the electrical transport through 10.4 nm long (30 base-pairs) homogeneous poly(dG)-poly(dC) molecules that were electrostatically trapped [5,6] between two Pt electrodes. In a parallel work, Kasumov et al. [7] reported ohmic behavior of the resistance of λ-DNA molecules deposited on a mica surface and stretched between rheniumcarbon electrodes. In another attempt to resolve the puzzle surrounding DNA conduction properties, de Pablo et al. [8] applied a different technique to measure single λ-DNA molecules on the surface in ambient conditions, the results of which could be found in his paper [9]. The present work investigates the characteristic current (I)-voltage (V) of DNA strands immobilized between two metal (Au) gaps when a magnetic field was applied perpendicular to the direction of DNA arrangement. The results generally highlight high sensitivity to surrounding magnetic field suggesting possible application as a magnetic sensor. Advanced Materials Research Vols. 535-537 (2012) pp 1350-1353 Online available since 2012/Jun/14 at www.scientific.net © (2012) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/AMR.535-537.1350 All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP, www.ttp.net. (ID: 161.142.24.130-15/06/12,03:59:47)