A nanodiagnostic colorimetric assay for 18S rRNA of Leishmania pathogens using nucleic acid sequence-based amplification and gold nanorods.

Background And Objective: We describe here a nanodiagnostic colorimetric assay for 18S rRNA of Leishmania pathogens that uses nucleic acid sequence-based amplification (NASBA) and gold nanorods (GNRs).

Methods: NASBA primers targeting 18S rRNA were used for amplification of RNA in an isothermal process. The electrostatic interactions between the phosphate groups of the RNA amplicons and the cetyl trimethylammonium bromide layer on the GNRs resulting in their aggregation.