Kanchan Chavan: F02-1336 Nanoconfinement for Multi-Step Reaction Cascade System
Welcome! Our research involves development and characterization of materials for fuel cells, particularly proton exchange membrane fuel cells, direct methanol fuel cells and biofuel cells. These materials find applications in devices ranging from the microwatt to the kilowatt scales, and will have a strong impact on future energy devices with minimal environmental impact.
Congratulations to Beryl Zhang ’18 who presented her poster, on Enzymatic hydrogel thickness measurements by AFM, at the at the Mid-Michigan Symposium for Undergraduate Research Experiences (Mid-SURE). Beryl helped Alex getting our new AFM-SECM system off the ground, measuring the thickness of hydrogels made using the slide coating technique. This approach will be used for electrochemical microscopy studies of single and multi-enzyme cascades.
Congrats to former group member Josh Gallaway who is starting a new tenure-track position in the Dept. of Chemical Engineering at Northeastern University. Josh’s research in our group was on redox complexes for mediating enzymatic reactions, but his recent studies have combined spectroscopic and electrochemical techniques to understand battery chemistry, especially zinc alkaline batteries. We can’t wait to see what Josh does at NEU!
Former postdoc Cenk Gumeci and Duyen Do have published new work on electrospun nanofiber-based bioelectrodes in Electrocatalysis. Electrospinning allows for the control of fiber diameter and density, and allow for very thin and highly efficient biocatalytic films. Current density reaching 10 mA cm−2 was observed for glucose oxidation, rivaling that of commercial carbon nanomaterials. This work was featured as cover art for the July 2017 issue.
A new paper by Erica Earl is available now in Physical Chemistry Chemical Physics (PCCP). In this paper, Erica uses a continuum model to demonstrate the effectiveness of channeling strategies in reaction cascades. She studied proximity, physisorption, and electrostatic interactions, three modes discussed in a recent review paper by our collaborators and us. The paper clearly demonstrates the effectiveness of electrostatic interactions for channelling of intermediates between active sites.
The continuum approach is useful for studying long-range interactions, but interactions specific to molecular structure must be assessed using molecular-scale modeling such as molecular dynamics. Our collaborative MD study, recently published in ACS Catalysis, complements this paper well.
Current Ph.D. student Yuanchao Liu has published new work on molecular dynamics (MD) simulation of electrostatic channeling in ACS Catalysis, collaborating with Dr. David P. Hickey of the Minteer group and Sigman group at the University of Utah. This is the first study of an artificial cascade using electrostatic channeling. In this work, we utilize MD simulations to describe the transport of anionic intermediates on a theoretical cationic peptide bridge, and identify rules for molecular-level design of electrostatic channeling.
MD simulations demonstrate design rules for designing electrostatic complexes (see videos after the break), and using MD studies as a foundational blueprint, our partners synthesized an enzyme complex using a poly(lysine) peptide chain as a cationic bridge between glucose-6-phosphate dehydrogenase and hexokinase (image below). Stopped-flow lag time experiments demonstrate the ability of the artificially linked enzyme complex to facilitate electrostatic substrate channeling.
This Fall, we’ll be presenting our work at PRiME 2016 in October and the AIChE National Meeting in November. Here are the details:
On Thursday February 25, Dr. Calabrese Barton will present an invited seminar at the ECS Detroit Local Section Meeting. The talk, entitled “Low-Cost Oxygen Reduction Catalysts Prepared from Transition Metals by High Pressure Pyrolysis” will follow a reception at 5:30 and dinner at 6:30 on the campus of Lawrence Institute of Technology in Southfield, MI. A seminar flyer and directions to Lawrence Tech can be found here.
Nate will receive his award at the Fall 2015 meeting of the ECS in Phoenix this October. He joins a long line of illustrious awardees, including academic “ancestors” Alan West and John Newman. We are particularly pleased that Nate’s award-winning paper appeared in a JES Focus issue honoring Adam Heller for his lifelong contributions to Electrochemistry.