Conferring the Midas touch on integrative taxonomy: a nanogold-oligonucleotide conjugate based quick species identification tool

Nanogold or functionalized Gold nanoparticles (GNPs) have myriad applications in medical sciences. GNPs are widely used in the area of nanodiagnostics and nanotherapeutics. Applications of GNPs in taxonomic studies have not been studied vis-à-vis its extensive medical applications. GNPs have great potential in the area of integrative taxonomy. We have realized that GNPs can be used to visually detect animal species based on molecular signatures. In this regard, we have synthesized ultra-small gold nanoparticles (<20 nm) and have developed a method based on interactions between thiolated DNA oligonucleotides and small sized GNPs, interactions between DNA oligonucleotides and target DNA molecules, and self-aggregating properties of small sized GNPs under high salt concentrations leading to visible change in colour. Exploiting these intermolecular and interparticle interactions under aqueous conditions, in present work, we have demonstrated the application of our procedure by using DNA oligonucleotide probe designed against a portion of the mitochondrial genome of the codling moth Cydia pomonella . This method is accurate, quick and easy to use once devised, and can be used as an additional tool along with DNA barcoding. We suggest that designing and selection of a highly specific DNA probe is crucial in increasing specificity of the procedure. Present work may be considered as an effort to introduce nanotechnology as a new discipline to the extensive field of integrative taxonomy with which disciplines like palaeontology, embryology, anatomy, ethology, ecology, biochemistry and molecular biology are already associated for a long time.