Effectual Gold Nanoprobe Sensor for Screening Horse Adulteration in Meat Products

Abstract

A gold nanoparticle (AuNP) probe strategy for testing meat authenticity was developed, which relies on the colorimetric differentiation of a particular DNA sequence, due to the differential aggregation profiles exhibited by the AuNPs in the presence or absence of specific target hybridization. Gold nanoparticles were conjugated with thiolated oligonucleotides for specifically identifying a 69 bp fragment of the horse cytochrome b gene. In the presence of a complementary target preventing aggregation of the AuNPs when acid was added, the reaction mixtures retained the original pink colouration of the colloidal particles, whereas they turned purple in the opposite event. Fresh meatballs, prepared using pure bovine meat, were used as blanks, producing a purplish coloured solution with a peak at ≥570nm. Horse meat was used as positive control and the pink colour obtained after hybridization exhibited maximum absorption at 524 nm. Both the specificity and sensitivity of the tests performed were 100%. Visual observations and spectroscopic data indicated that the coloration produced by the AuNPs (positive-pink, negative-purple) was very stable, showing no change under normal laboratory conditions. The use of AuNPs for the colorimetric detection of DNA targets from undeclared species in meat products provides an inexpensive and easy-to-perform alternative to common molecular assays. The technology described here can be further developed to accommodate detection of many cases of adulteration and fraudulent practices.

Effectual Gold Nanoprobe Sensor for Screening Cow Milk Adulteration in Goat Milk—Comparison With Conventional PCR

“…The developed method is based on the specific target hybridization of the AuNPs with a specific DNA sequence. In general, colloidal solutions of AuNPs with diameters ranging from 5 to 20 nm show a pink-red color (Figure 1), due to their optical absorption peak at around 520-525 nm, caused by the collective excitation of the free conduction band electrons of the dispersed particles, known as the surface plasmon resonance (Houhoula et al, 2017;Bohren & Huffman, 1983;Li & Rothberg, 2004…”

“…Over the last years, new strategies for the identification of the origin of food have been introduced, which are related to the development of precise nanoparticle-based probes and are competent for detecting DNA target sequences (Ali et al, 2011(Ali et al, , 2012(Ali et al, , 2014Houhoula et al, 2017). Nanotechnology and, especially gold nanoparticles (AuNPs) chemistry, offers innovative opportunities for quick and easy analysis of authenticity, since it is capable to evidence even low level of adulteration, thanks to their particular optical properties (Zeng et al, 2011).…”

“…Nanotechnology and, especially gold nanoparticles (AuNPs) chemistry, offers innovative opportunities for quick and easy analysis of authenticity, since it is capable to evidence even low level of adulteration, thanks to their particular optical properties (Zeng et al, 2011). AuNPs, have been used effectively as colorimetric sensors for visual identification and they are suggested as a cheaper and simple alternative to other molecular methods since they can to work in different food matrices (Ali et al, 2011(Ali et al, , 2012(Ali et al, , 2014Houhoula et al, 2017). The aim of the present study is to demonstrate that functionalized AuNPs can be used for the development of a simple DNA detection procedure for the identification of cow milk adulteration in goat milk, and to compare its sensitivity with the most used PCR method.…”

New Advances in Lateral Flow Immunoassay (LFI) Technology for Food Safety Detection

“…Many researchers use SPR to test for adulteration in milk, baby food, pet food, pure honey, tequila and alcoholic beverages and meat sausages. Vikas et al [ 65 ] studied the effect of adding a Ag film fiber-optic SPR probe to increase the sensitivity of glucose and fructose in adulterated honey samples to 24% and 37%, respectively. Houhoula et al [ 66 ] investigated the adulteration of the horse cytochrome B gene in meatball samples by observing fluctuations in the wavelength of the acid-adding solution.…”

Application of DNA-Nanosensor for Environmental Monitoring: Recent Advances and Perspectives

“…The presence of horse meat avoids acid-induced aggregation of AuNPs as it is protected by dsDNA formed by horse cytochrome ssDNA binding to probe and AuNPs appear pink. In the absence of horse meat, the AuNPs appear purple due to acid-induced aggregation as ssDNA fails to protect AuNPs [ 137 ]. DNA-functionalized AuNPs are useful for detection of genotoxic, 2-anthramine, acridine orange, and 2-naphthylamine in water samples from Henan province, China [ 138 ].…”