PreS1 peptide-functionalized gold nanostructures with SERRS tags for efficient liver cancer cell targeting

Early detection is the most effective mean of improving prognosis for many fatal diseases such as cancer. In this
context, the Surface Enhanced Resonance Raman Scattering (SERRS) technique is being proposed as alternative
to fluorescent methods in detection of biomarkers, because SERRS nanostructures are bright as fluorescent tags
but more stable and clearly detectable using the narrow Raman “fingerprints” of a suitable reporter. Here we
show that biocompatible SERRS active gold nanostructures, functionalized with an engineered PreS1 peptide
(AuNP@PEG-PreS1), detect the presence of the SerpinB3 antigen overexpressed on liver tumor cells, a biomarker
of the onset of liver cell carcinomatous transformation. A proper engineering of the targeting unit, linked to the
nanostructure by a polymer chain, affords a sensitivity and specificity larger than 80%, at subnanomolar concentrations.
Taking into account the high sensitivity of SERRS and that SB3 overexpression is an early event in
liver cell carcinomatous transformation, AuNP@PEG-PreS1 nanostructures could be used in routine diagnostic
activities, to improve the accuracy of HCC detection in particular in patients with chronic liver diseases.