Investigating Electrochemistry in Confined Volumes

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We are making contributions in Electrochemistry, a field offering unique solutions to some of society's important problems in renewable energies, diagnostics, and corrosion. In electrochemistry, two scales have dominated developments: large systems governed by semi-infinite linear diffusion and single entity electrochemistry. There is an experimental and theoretical framework gap for intermediate scale materials in confined volumes, where the balance between mass transport processes and kinetics is altered yielding unexpected electrochemical behavior. This discovery program targets electrochemistry in three types of confined volumes; 1-redox liposomes, 2-electrochemically luminescent (ECL) nanospheres and 3-gaps defined during electrochemical microscopy. 1)Understanding the mechanism of oxidatively-triggered membrane disassembly in redox-responsive liposomes. We will carry out the first comprehensive study of membrane dynamics in an oxidatively responsive bilayer. We intend to prepare ferrocene-deuterated analogues of the two responsive amphiphiles we have employed previously. To complement these structures, commercially available materials will be used with non-deuterated ferrocenes to prepare chain-perdeuterated amphiphiles. These materials will be incorporated into multilamellar vesicles or liposomes for electrochemical, solid state NMR and small-angle X-ray scattering studies. Our objective is to extract dynamic information about the oxidatively responsive membrane disassembly process in real time. 2) Studies of electrochemically luminescent nanospheres.  We will establish an experimental and theoretical framework to understand the fundamental basis for the newly discovered amplification of the electrogenerated chemiluminescence response in polymeric nanospheres. The micelle architecture will generally involve a hydrophobic core, a high density of ECL metal centers, a biocompatible block and a biological recognition unit at the periphery of the micelle. The ECL amplification of the nanospheres relative to the disassembled ECL block copolymer will be measured using our ECL Detection System capable of quantitative simultaneous acquisition of electrochemical and ECL data. We will then analyze the results using kinetic modelling that considers heterogeneous, homogenous kinetics and mass transport confinement effects, with the aim of extracting dynamic information about the co-reactant electrochemical luminescence in self-assembled polymeric nanospheres in real time. 3) Confined Volume defined during electrochemical microscopy. We propose to develop super-resolution SECM. To achieve super-resolution, we must work around the theoretical limit on SECM image resolution routed in diffusional broadening. We are proposing to overcome past limitations and use imaging processing to achieve super-resolution SECM using breakthroughs in optical imaging where algorithm-based approaches have led to major discoveries, including the Nobel Prize in 2014.