Optical trapping and sensing platforms based on plasmonics were developed due to the desire to both trap and manipulate ever smaller particles using noninvasive optical techniques. Through careful engineering of the plasmonic structures, a Fano resonance can yield a surprisingly large improvement to the trapping efficiency for nanoparticles. Using a split ring array, we have demonstrated trapping of particles as small as 10 nm and have exploited the SIBA effect to improve the trap stiffness for gold nanoparticles. We have extended the technique to sense and determine the phase of E-coli bacteria and have explored thermal effects which can contribute to the trapping processes. Here, we discuss characterization of the devices themselves, to engineer them for specific applications such as enhanced photoluminescence from nano-emitters, particularly nanographenes.
|