Surface enhanced resonance Raman scattering (SERRS) is an analytical technique with several advantages over
competitive techniques in terms of improved sensitivity and multiplexing. We have made great progress in the
development of SERRS as a quantitative analytical method, in particular for the detection of DNA. SERRS is an
extremely sensitive and selective technique which when applied to the detection of labelled DNA sequences allows
detection limits to be obtained which rival, and in most cases, are better than fluorescence. Here the conditions are
explored which will enable the successful detection of DNA using SERRS. The enhancing surface which is used is
crucial and in this case suspensions of nanoparticles were used as they allow quantitative behaviour to be achieved and
allow analogous systems to current fluorescence based systems to be made. The aggregation conditions required to
obtain SERRS of DNA are crucial and herein we describe the use of spermine as an aggregating agent. The nature of the
label which is used, be it fluorescent, positively or negatively charged also effects the SERRS response and these
conditions are again explored here. We have clearly demonstrated the ability to identify the components of a mixture of 5
analytes in solution by using two different excitation wavelengths and also of a 6-plex using data analysis techniques.
These conditions will allow the use of SERRS for the detection of target DNA in a meaningful diagnostic assay.
Gold and silver nanoparticles functionalized with oligonucleotides can be used for the detection of specific
sequences of DNA. We show that gold nanoparticles modified with locked nucleic acid (LNA) form stronger
duplexes with a single stranded DNA target and offer better discrimination against single base pair mismatches
than analogous DNA probes. Our LNA nanoparticle probes have also been used to detect double stranded DNA
through triplex formation, whilst still maintaining selectivity for only complementary targets. Nanoparticle
conjugates embedded with suitable surface enhanced resonance Raman scattering (SERRS) labels have been
synthesized enabling simultaneous detection and identification of multiple DNA targets.