Publication:
Simple Colorimetric DNA Biosensor Based on Gold Nanoparticles for Pork Adulteration Detection in Processed Meats

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Abstract

In order to develop simple sensing system for pork adulteration in processed meats, the DNA biosensor based on 20 nm gold nanoparticles (AuNPs) with aggregation property has been developed as a simple colorimetric detection of target DNA. Adsorption of single-stranded (ss) DNA on AuNPs protects the particles against salt-induced aggregation. However, mixing and annealing of a 27-nucleotide (nt) ssDNA probe on AuNPs with denatured DNA of different processed meats differentiated between perfectly matched and mismatch hybridization at a critical annealing temperature (55 °C). The AuNPs change color from red to purple, in 10 mM phosphate buffer saline (PBS). At a hybridizing temperature (55 °C), non-target mismatched DNA provided hybridization products allowing probe to be free and adsorbed to AuNPs. This prevented AuNPs from salt-induced aggregation as the color still red. In matched DNA, hybridization would occurred, allowing probe to be occupied. This facilitated AuNPs from salt-induced aggregation and induced colorimetric change of particles from red to purple. These signals could be observed easily with naked eye. This label-free DNA nanobiosensor should find applications in food analysis and other DNA based screening.

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Keywords

Colorimetric sensors,, DNA biosensor,, Gold nanoparticles,, Pork adulteration,, Processed meats

Citation

Sensors & Transducers, Vol. 208, Issue 1, January 2017, pp. 7-13