As our world progresses through technological advancements, much of our planet regresses as an effect of climate change, highlighting a need for underutilized resources to be brought to the forefront of industry. One avenue for transforming abundant resources into useful chemicals for generating sources like fuel is the catalytic upgrading of biomass derived molecules. However, catalysts traditionally used for these reactions are not stable to contaminants in biomass mixtures, such as water or organic acids. For biomass derived molecules to serve as precursors for biofuel and other related energy sources, more stable and efficient catalysts are needed. Our group has recently shown that a bifunctional acid–base MOF with co-localized acidic and basic sites outperforms a MOF with randomly dispersed acid–base sites for the aldol condensation reaction. To further demonstrate the importance of having the acid and base groups co-localized, I synthesized and tested three control frameworks for comparison: (1) a framework with no functionality, (2) a framework with only acidic sites, and (3) a framework with only basic sites. I then tested stability and recyclability of the bifunctional acid–base frameworks by conducting recycling experiments. I resubjected the same sample to reaction conditions for a total of 5 cycles. After each cycle, I used 1H NMR to quantify the conversion of starting material to ensure that there were no changes in catalytic activity. Lastly, I used powder X-ray diffraction (PXRD) to ensure that the catalysts maintained their crystalline structure after 5 cycles. Here I show that metal–organic frameworks (MOFs), a class of porous crystalline solids, can be used as efficient and recyclable catalysts for the aldol condensation, an important reaction for biomass conversion. Overall, this work illustrates the stability and reusability of metal organic frameworks as catalysts and thus their potential for utility in biomass upgrading reactions.

Despite recent advances in monoclonal antibody (mAb) technology and its rapidly growing market share, therapeutic targets for mAbs are currently limited to membrane proteins which consist of up to 30% of total proteins encoded by the human genome. The other 70% of cytosolic protein targets remain inaccessible inside the cell. Thus, research into intracellular protein delivery is critical to unleash the full potential of protein therapeutics. For example, mAbs can target oncogenes, enzymes, and the complex signaling cascades within the cell, unlocking a completely new domain of protein targets. Current methods for intracellular protein delivery involve either low protein throughput with minimal cell damage/cytotoxicity or high throughput approaches that compromise cell viability. The Gao lab recently developed a highly efficient technology that allows small proteins to be directly delivered into the cytoplasm with minimal damage to the cell, by cholesterol tag. To further this research, we developed a new version of the tag via the covalent linkage of Coomassie Blue dye with 2-hexyldecanoic acid, branched alkyl chains. This new tag could deliver mAbs, specifically immunoglobulin G (IgG), labeled with fluorescent dye. Through this project, I (i) carried out organic synthesis of the new tag, (ii) delivered secondary antibody into HeLa cells, (iii) confirmed protein internalization through fluorescent microscopy, and (iv) delivered anti-Vimentin primary antibodies for live cell imaging of intermediate filament. Ultimately these four aims demonstrate successful intracellular mAb delivery while maintaining its native protein structure. This allows us to utilize this technology to deliver protein therapeutics targeting all kinds of cytosolic proteins including oncogenic proteins such as p53, RAS, and MYC.

The synthesis of key organic molecules often requires toxic, expensive, non-reusable reduction agents and extreme conditions. In recent years, electrochemistry has emerged as a sustainable alternative to standard methods, but this approach is often hindered by high energy barriers for electron transfer to the substrate. Electrocatalysts address this challenge by shuttling charge between the electrode and dissolved substrates, accessing lower transfer barriers, and reducing the overall energy needed. Current electrocatalysts, however, cannot stabilize reactive intermediates, which often leads to harmful side reactions and degradation of the electrode. We hypothesize that redox-active supramolecular cages can address this limitation by both shuttling charge and providing unique microenvironments capable of stabilizing intermediates. Previously, we synthesized two tetrahedral supramolecular cages that incorporate redox-active perylene diimide (PDI) and pyromellitic diimide (PMDI) motifs. Using cyclic voltammetry, we then showed that both cages can lower the voltages required for the electroreduction of vicinal dihalides to alkenes, indicating electrocatalysis. To better understand these results, I used density-functional theory (DFT) calculations to obtain computer models of the PDI and PMDI cages. These DFT-optimized structures revealed significant differences in charge density between redox centers due to electron-donating functional groups, which may explain why the PMDI cage lowered the substrate reduction voltages more than the PDI cage. With these models, I have also studied the shape and volume of the cages’ internal cavities, thereby providing information about substrate compatibility. I am conducting additional DFT analysis to understand how modifications to the ligand motifs may alter the electrocatalytic behavior. By continuing to investigate supramolecular cages for reductive electrocatalysis, I aim to contribute to the development of low-waste synthetic strategies for the production of alkenes and other commercially significant organic compounds.