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Molecularly mediated assemblies of nanoparticles open prospects for the combination of nanostructure-tuning capabilities with unique electrical, optical, and magnetic properties.[1] Quantum dots (QDs) have attracted increasing interest as fluorescent probes owing to their photostability, continuous absorption spectra, and efficient and tunable emission.[2] Different approaches to the assembly of QDs to explore their collective optical properties have been reported.[3] Mediation of the assembly of QDs by a small molecular analyte, such as glucose, may yield a facile means of fabricating QD arrays with tunable optical properties in response to concentration changes of the analyte, even in a living system. However, such approaches remain largely unexplored. Changes in the glucose level within cells are indicative of many cellular processes.[4–6] For example, glucose plays an important role in both energy metabolism and biosynthesis in the cells of most mammalians [5] and could thus potentially be used in cancer therapy to restrict cancer-cell growth.[6] Yet how cells sense and adapt to changes in the glucose level is not well understood. Although numerous fluorescent glucose probes have been developed from QDs, only a small number are potentially practical for intracellular imaging.[7] On the basis of the observation by Yoon and Czarnik that the fluorescence of a fluorophore changed upon the reaction of glucose with a boronic acid group attached to the fluorophore,[7a] Singaram and co-workers were the first to develop fluorescent QDs for glucose sensing.[7b] Their approach involved reversible competition between glucose and CdSe QDs …