Sensing of supramolecular assembly in vivo has been a struggle for current research because a limited number of assays can probe this effectively. Firefly luciferin has been widely used as an in vivo reporter of adenosine triphosphate, magnesium cations, and esterase activity because of its highly selective enzyme catalysis and high quantum yield when oxidized in the presence of adenosine triphosphate and magnesium cations. The emitted photon is of a yellow-green color thus detection has been possible in vivo from cells to mammals by a simple luminescence assay. Caging, or rendering the firefly luciferin molecule incompatible for luciferase enzyme, has been accomplished most commonly by appending electron withdrawing groups to the 6’-hydroxyl position or esterification of the thiazole moiety. The caged luciferin then undergoes a reaction to yield its native form, resulting in emission of a photon upon oxidation and reporting the desired reaction or process. The goal of our research is to use firefly luciferin as a reporter of supramolecular assembly by a novel method of caging, reversibly with a host molecule (cyclodextrins and cucurbiturils). This talk will describe the synthesis and characterization of a novel set of firefly luciferin derivatives for use in the luciferin-luciferase type assays with the goal of detecting host-guest interactions. This talk will illustrate how supramolecular assembly and its predictability can be used to design novel biocompatible systems to overcome the challenges of a highly competitive cellular environment.