From a synthetic perspective, the design of a nanosensor library is mainly determined by the chemical properties of the nanomaterial. Since a complete overview would be beyond the scope of this perspective, interested readers are directed toward several excellent reviews. For example, gold nanoparticles can be easily modified via thiols. In contrast, sp -hybridized particles such as SWCNTs can be modified via non-covalent, adsorption-based functionalization via π-stacking and covalent functionalization via nucleophilic, electrophilic, or radical reactions. Due to their ease of functionalization and their high sensitivity toward their chemical environment (coronae) SWCNTs are interesting building blocks that are i) easy to modify chemically and ii) able to translate binding events into optical signals (Figure ). Furthermore, SWCNTs have historically been used abundantly with non-rational design concepts that are easily scalable in screening approaches. We will therefore, discuss differences in high throughput methods by using SWCNT-based sensors as an example.