Strategies for the surface biofunctionalization of sulfur-based chalcogenide infrared optical glasses

Effective surface functionalization plays a critical role in the selectivity and sensitivity of sensing devices. While chalcogenide glasses (ChG) have received lot attention as promising optical materials for mid-IR biosensors, there been just few reported instances their successful (bio)functionalization. In present work, we explore three different approaches grafting heterobifunctional derivatives on Ge25Sb10S65 substrates. One these consisted use traditional silane chemistry to functionalize hydroxyl moieties ChG, while other two are novel strategies based potential reactivity maleimide cyclooctyne sulfhydryl at inorganic glass matrix. Using approaches, biotinylated surfaces were prepared selective fluorescent-labeled protein was then validated via IR spectroscopy, AFM fluorescence. Our results showed that biofunctionalization Ge-Sb-S ChG achieved by all methods. Moreover, process can be easily adapted substrates with any type geometry molecules surface, paving way future development infrared systems exhibiting bio selectivity.