An easy way to realize SPR aptasensor: a multimode plastic optical fiber platform for cancer biomarkersdetection

The introduction of new compact systems for sensitive, fast and simplified analysis iscurrently playing a substantial role in the development of point-of-care solutions aimed to assist both prognosis and diagnosis. Here we report a simple and low cost biosensor based on Surface Plasmon Resonance(SPR) taking advantage of a plastic optical fiber (POF) for thedetection of Vascular endothelial growth factor (VEGF), selected as a circulating protein potentially associated with cancer. Our system is based onto two crucial aspects. By one hand, the functional layer which allows the transduction signal isbased on DNA aptamers, short oligonucleotide sequences that bind to non-nucleic acid targets with high affinity and specificity. By the other hand, the light guiding structure is based on a POF with a planar gold layer as the sensing region, which is particularly suitable for bioreceptors implementation.The sensor revealed to be really useful in the interface characterization.The developed system is relatively easy to realize and could well address the development of a rapid, portable and low cost diagnostic platform, with a sensitivity in the nanomolar range.