Department of Chemistry
Indian Institute of Technology Delhi

Quantum Chemistry and Biology: From new catalysts for photons to specific fuels, to novel therapeutics in fight against the superbugs

Dr. Prashant Nagpal
University of Colorado Boulder, Boulder, CO 80303, USA,

Date: March 14th 2018 (Wednesday)
Time: 4:00 PM
Venue: Committee Room, Chemistry Department, 6th Floor

Photosensitized chemistry in small semiconductor nanocrystallites can be used as a useful tool in wide-ranging applications for converting photons-to-chemical bonds or specific solar fuels in designer inorganic and biocatalysts, to light-activated redox therapies in the fight against potent superbugs. In this talk, I will begin by describing my groups success in design and fabrication of high-efficiency and highly selective photocatalytic materials, ranging from inexpensive and stable inorganic metal-oxide nanotube catalysts membranes using elemental doping, to nanostructuring two-dimensional materials to selectively tune photophysics and improve important physical properties like exciton-phonon coupling and lifetime of photoexcited charge carriers. I will describe a novel electrochemical anodization technique developed in our lab for making a wide-variety of stable and inexpensive doped metal-oxide nanotubes and their standalone membranes, which has successfully realized titanium dioxide nanotube array growth with simultaneous anion-, cation-, and co-doping. Using a series of optoelectronic (optical spectroscopy, scanning tunneling spectroscopy, current sensing AFM) and electrochemical (voltammetric and impedance) characterizations, we systematically studied the dopant (anionic and cationic) effects in photocatalytic water splitting from the aspect of light absorption, charge transport, and charge transfer. Using the lessons learned in the design of these inorganic catalysts, I will describe our invention of new artificial quantum dot-cell nano biohybrid organisms (nanorgs) as solar-powered living factories. Using synthetic biology to design molecular machinery in bacteria, my group has created artificial organisms which combine the multifunctional properties of engineered nanomaterials with the designed metabolic networks for specific photon-to-fuel pathways. With non-growing nanorgs in buffered water, we recently demonstrated air-water reduction with high turnover frequency for ammonia production (3.86 × 107 mol NH3/ mol cells), creating hydrogen from water reduction, and formic acid from carbon dioxide-water reduction. In the end, I will demonstrate how my group is developing highly-selective nanotherapies using quantum-confined semiconductor nanomaterials, as a two-pronged strategy to potentiate and sensitize existing antibiotics and develop a new class of potentially “resistance-free” therapies to kill multidrug-resistant pathogens or superbugs. Towards these novel precision therapeutics, I will describe how we are developing principles in the emerging field of “Quantum Biology,” to use precisely tailored molecular interactions in the cellular environment and develop targeted therapeutics to eliminate superbugs and address the burgeoning problem of antimicrobial drug-resistance.

All are cordially invited to attend.
Convener (Seminars)