The invention provides a method for use in the detection of a target nucleic acid comprising the steps of: (i) contacting a single-stranded probe nucleic acid with a sample of interest under conditions effective to generate a probe/target nucleic acid duplex by specific hybridisation of said probe nucleic acid to a target nucleic acid, if said target nucleic acid is present; (ii) contacting any probe/target nucleic acid duplex with an exonuclease to effect digestion of the duplex and release of a label molecule from the duplex; and (iii) detecting the label by Raman spectroscopy.
