Experimental investigation of surface passivation chemistries for optical nanotweezers

Optical nanotweezers are actively investigated as a powerful means to reversibly trap and study the properties of nanoscale biological objects and nanoparticles. To ensure that the objects can be reversibly trapped and released on demand, while also preventing undesired adsorption onto surfaces, surface passivation is of paramount importance. Although the surface chemistries examined in this study hold broad applicability across diverse nanotweezing platforms, our investigation primarily focuses on the newly reported Geometry-induced Electrohydrodynamic Tweezers (GET) as the nanotweezing platform. Geometry-induced electrohydrodynamic tweezer (GET) is a scalable and high-throughput technique for trapping and manipulating nanoscale objects. Here, we are investigating the antifouling properties of a GET nanotweezer passivated with Poly(ethylene glycol) methyl ether thiol (PEG), (1-Mercaptoundec-11-yl)tetra(ethylene glycol) (OEG), 11-Mercaptoundecanoic acid (MUA) and 1-Mercapto-11-hydroxy-3,6,9-trioxaundecane (DMOL). The confirmation of the passivated surfaces' wettability and the SAM vibrational properties is achieved through contact angle analysis and FTIR spectroscopy respectively.