Zheng Zeng – Seminar/Ph.D. Thesis Defense – Wednesday, October 11, 2017 at 1:00 P.M.

JSNN – Zheng Zeng – Ph.D. Thesis Defense/Wednesday Seminar

Candidate: Zheng Zeng

Advisor and Committee Chair: Jianjun Wei, Ph.D.

Department: Nanoscience

Date: Wednesday, October 11, 2017

Time: 1:00 P.M. – 3:00 P.M.

Location: JSNN Auditorium

2907 E. Gate City Blvd., Greensboro, NC 27401

Title: “Nanoscale Reactions in Opto-Magneto-Eelectric Systems.”

Abstract:

My research is interdisciplinary in the areas of chemistry, physics and biology for better understanding of synergies between nanomaterials and opto-magneto-electric systems aimed at the practical applications in biosensor, energy (energy storage and electrocatalysis), and biomimetics, in particular, the associated electron transfer, light-matter interactions in nanoscale, such as surface plasmon resonance (SPR) (nanoplasmonics), and magnetic field effect on these phenomena with targeted nanomaterials. Specific research thrusts include: (1) investigation of surface plasmon generation from a novel nanoledge structure on thin metal film. The results are used for the nanostructure optimization  for a nanofluidic-nanoplasmonic platform that may function as a multiplexed biosensor for protein biomarker detection; (2) examination of magnetic field effect on uniformly deposited metal oxide on electrospun carbon nanofiber (ECNF) scaffold for efficient energy storage (supercapacitor) and electrocatalytic energy conversion (oxygen reduction reduction). The results suggest that the magnetic spin polarization of unpaired electrons in transition metal oxide is the major factor to facilitate the electrochemical electron transfer kinetics, thus the performance enhancement. (3) magnetic response of cryptochrome 1 (CRY1) in photoinduced heterogeneous electron transfer (PHET). Cryptochromes are flavoproteins whose light-induced photocycle and magnetoreception are implicated to underpin biological functions and potential biomimetic magneto-opto-electronics. We, for the first time, observed and examined the magnetic sensitivity of cryptochromes (CRYs) in PHET by immobilizing the CRY1 at a gold electrode using a combined opto-magnetic electrochemical setup. These results present the magnetic field enhanced PHET of CRY1 to the electrode by voltammetry, exhibiting a magnetic responsive rate constant and electrical current changes. A mechanism of the electron transfer, which involves the light activated spin-correlated radical pairs in CRY1, is proposed to understand the magnetic response.m