(4eh) Designing Nano-Scaled Micro-Environments for Molecular Catalysis and Synthetic Biology | AIChE

(4eh) Designing Nano-Scaled Micro-Environments for Molecular Catalysis and Synthetic Biology

Authors 

Walker, D. A. - Presenter, Northwestern University



One of the canons of organic chemistry has been that a molecule's properties are inherently 'coded' by its chemical structure. This perspective, however, is an over simplification as there are a multitude of examples demonstrating that environmental factors contribute to a molecule's properties equally to, if not more than, the chemical structure. This is best exemplified by living systems – the complexity of human life is created out of just 21 amino acids which are strung together to create proteins and other sophisticated molecular machines. By controlling the environments around this handful of chemical species, and as such controlling their nanoscale interactions, nature has developed an endless list of highly efficient molecular machines.

Nanoparticles (NPs) provide a useful platform through which we can begin to probe the effects of molecular environments and various types of inter‐ or intra‐molecular interactions. Electrostatic interactions tend to be one of the more versatile interactions at this length‐scale as they can be attractive or repulsive, short‐ or long‐ranged, and their magnitudes readily controlled. Here we demonstrate that on-particle self-assembled monolayers can be used to create artificial microenvironments which control the chemical properties of organic molecules. By controlling geometric orientations and electrostatic interactions one can essentially program the pKa of carboxylic acids and redox potentials of organometallics in a manner analogous to that of proteins and enzymes. Additionally, using NPs functionalized with mixed self-assembled monolayers (mSAMs) one can elucidate important mechanistic information for catalytic diads or triads.

The ability to create artificial micro-environments offers a fundamentally new approach, as inspired by biology, for synthetic organic chemists. Furthermore, in the field of synthetic biology artificial microenvironments show great promise for tuning the properties of existing enzymes and proteins while, simultaneously, allowing for their stability and function in non-physiological chemical environments.