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Journal of Nanomaterials
Volume 2011, Article ID 781098, 11 pages
http://dx.doi.org/10.1155/2011/781098
Research Article

Nanobiosensor for Detection and Quantification of DNA Sequences in Degraded Mixed Meats

1Institute of Nano Electronic Engineering (INNE), Universiti Malaysia Perlis, 01000 Kangar, Perlis, Malaysia
2Halal Products Research Institute, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
3School of Materials Engineering, Universiti Malaysia Perlis, 01000 Kangar, Perlis, Malaysia
4Institute of Tropical Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
5Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia

Received 9 November 2010; Accepted 10 April 2011

Academic Editor: Claude Estournes

Copyright © 2011 M. E. Ali et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A novel class of nanobiosensor was developed by integrating a 27-nucleotide AluI fragment of swine cytochrome b (cytb) gene to a 3-nm diameter citrate-tannate coated gold nanoparticle (GNP). The biosensor detected 0.5% and 1% pork in raw and 2.5-h autoclaved pork-beef binary admixtures in a single step without any separation or washing. The hybridization kinetics of the hybrid sensor was studied with synthetic and AluI digested real pork targets from moderate to extreme target concentrations and a sigmoidal relationship was found. Using the kinetic curve, a convenient method for quantifying and counting target DNA copy number was developed. The accuracy of the method was over 90% and 80% for raw and autoclaved pork-beef binary admixtures in the range of 5–100% pork adulteration. The biosensor probe identified a target DNA sequence that was several-folds shorter than a typical PCR-template. This offered the detection and quantitation of potential targets in highly processed or degraded samples where PCR amplification was not possible due to template crisis. The assay was a viable alternative approach of qPCR for detecting, quantifying and counting copy number of shorter size DNA sequences to address a wide ranging biological problem in food industry, diagnostic laboratories and forensic medicine.