LSPR is an optical phenomenon which is used for a number of applications such as bio-sensing and medical diagnostics. These methods have the potential to detect early indications of disease and has over the last few years been proven promising due to its high sensitivity and the small amount of reagents being
used.
This thesis presents a setup using spectrometer and light source focused primarily within visible light, and is coupled with multimode fibers attached to an index matching gel and a sensor segment using a 2x2 coupler. The sensor is comprised of a hydrogel representing a Fabry-perot cavity with gold nanorods immobilized within. Light is propagated through optical fibers into
the hydrogel and the light scattering back is measured with the spectrometer. LSPR measurements were performed on multiple pre-gel solutions with differing polymer density and the spectral data gathered were analyzed. Results showed an increase in FWHM and a slight red shift when increasing the polymer
hydrogel density from 5 to 10 wt%. A further increase in polymer density led to periodic signals dominating the spectra. It is argued that this may be caused by interference on the signal originating from a gap in fiber-gel interface. Or that it is caused by reflections from gel-liquid interface mixing with reflections from fiber-gel interface due to the increased reflectivity higher polymer densities
provide.