  An early detection of different tumor subtypes is crucial for an effective
guidance to personalized therapy. While much efforts focus on decoding the
sequence of DNA basis to detect the genetic mutations related to cancer, it is
becoming clear that physical properties, including structural conformation,
stiffness, and shape, as well as biological processes, such as methylation, can
be pivotal to recognize DNA modifications. Here we exploit the Surface Enhanced
Raman Scattering (SERS) platform, based on disordered silver coated--silicon
nanowires, to investigate genomic DNA from subtypes of melanoma and colon
cancers and to efficiently discriminate tumor and healthy cells, as well as the
different tumor subtypes. The diagnostic information is obtained by performing
label--free Raman maps of the dried drops of DNA solutions onto the Ag/NWs mat,
and leveraging the classification ability of learning models to reveal the
specific and distinct interaction of healthy and tumor DNA molecules with
nanowires.
