the chemistry
of renewable energy
Inorganic nanocrystals (NCs) have generated considerable interest as fluorophores owing to their size-dependent physical properties caused by quantum confinement. Broad absorption, narrow and tunable emission, high quantum yields, high two-photon absorption cross-sections and appreciable photostability are all properties that engender the utility of NCs for bioimaging applications. We work with the Bawendi group to translate NCs from imaging agents to sensing agents by exploiting fluorescence resonance energy transfer as a signal transduction mechanism between an analyte-sensitive fluorophore that is conjugated to the surface of the NC. The confluence of NC photophysical properties and surface derivatization methods has opened the way for the development of NC-conjugates for bio-sensing and cellular sensing applications.
To give you an idea of the power of our approach, we have begun developing new NC-based optical sensors for the metabolic profiling of growing tumors. Experiments in live animals (in collaboration with the Jain group at MGH) use our novel NC complexes to provide spatiotemporal maps of the concentration profile of determinants of tumor growth metabolism. Understanding the dynamic relationship among tumor acidosis (pH), oxygen tension (pO2) and nutrient levels (pGlucose) in the tumor microenvironment during disease progression and treatment is critical to developing heightened therapy responses. These studies offer a rational approach to the discovery of new and more efficacious cancer therapies.