Development of a novel electrochemical DNA-sensor

ANYL 111

Sudha Shrestha, s.shrestha@reading.ac.uk1, C. Mills2, and S. C. E. Tsang1. (1) School of Chemistry, University of Reading, P. O. Box 224, Whiteknights, Reading, RG6 6AD, United Kingdom, (2) Smith Detection, 459 Park Avenue, Bushey, Watford, Herts, WD23 2BW, United Kingdom
Simple, sensitive, versatile, inexpensive and rapid methods for detection of analytes are the key parameters in biosensor developments. At present, most established techniques for detection of nucleic acids require specific and expensive labelled nucleic acids, which include radioactive, fluorescent and chemiluminecent methods. On the other hand, a simple method that utilizes electrochemical impedance or field effect measurements of an electrode surface modified with a single stranded nucleic acid in order to detect a measurable shift of impedance upon recognition of complementary oligonucleotides has recently emerged as one promising direction. As a result, development of an ultra-sensitive semiconducting oxide surface in order to detect a small electrochemical change at the electrode/electrolyte interface has a prospective as an electrochemical biosensor. In this conference, we will present our work on the development of a new rare earth oxide based sensor for nucleic acid detection This comprises an ultra-thin layer praseodymium oxide (Pr6O11) deposited on tin-doped indium oxide (ITO). The specific sensing property of the praseodymium oxide will be particularly discussed. We will also present our work on the chemical modification of the sensor surface which includes silanization of the hydroxyl surface with (3-aminopropyl) trimethoxysilane (APTMS), followed by attachment of thiol-modified oligonucleotide via the use of a cross-linker, the sulfosuccinimidyl 4-(N-maleimidomethyl) cyclohexane-1-carboxylate (sSMCC). The success for each chemical step has been verified by FTIR and thermogravimetric analysis (TGA) and will be presented in this meeting. Finally, the sensing performances of this new solid-state sensor for complimentary oligonucleotides in solution using impedance analysis will be shown.
 

General Papers
7:00 PM-9:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster

Division of Analytical Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006