Towards V-shaped Plasmonic probes made by exploiting 3D printers and UV-cured optical adhesives for Medical applications.

Optical biosensors based on plasmonic phenomena are used in several fields, such as medical applications. This work presents simple sensor development phases to realize a small-size, highly sensitive, V-shaped, and low-cost surface plasmon resonance (SPR) platform. First, a resin block was achieved by a 3D printer with a V-shaped slot on its surface. To carry out a mirror on the slides of this slot, a silver layer was sputtered before a UV-cured optical adhesive filled the slot to achieve the core of a multimode optical waveguide. Then, a photoresist layer was deposited by spinning on this V-shaped optical waveguide to improve the sensor’s performance and the gold’s adhesion on the surface. Finally, a gold nanofilm was sputtered to excite the SPR phenomenon. On this sensitive gold surface, receptor layers can be deposited. In this work, the production steps and the experimental characterization of the sensor were presented. Furthermore, the V-shape geometry of the SPR probe could be used to connect it with the Light Emission Diode (LED) and the Charge Coupled Device (CCD) of smartphones for IoT-based Medical applications.