Single Molecule Study of Beta-Carotene using Scanning Tunneling Microscope (Up-close and Personal Investigation of Beta-Carotene)
Year: 2010
Type: article
Abstract: Single Molecule Study of Beta-Carotene using Scanning Tunneling Microscope (Up-close and Personal Investigation of Beta-Carotene) (101 pp.) Director of Dissertation: Saw W. Hla We mimic beta-carotene (β-carotene) environment in plant leaves by using Au(111) as a substrate and conduct single molecule level studies in ultra high vacuum at low substrate temperatures of 77 K and 4.2 K.The STM images and manipulations studies identify five mechanically stable beta-carotene conformations on this substrate, with two never before reported by experiments.We confirm beta-carotene single molecule switching and molecular wire functionality.The beta-carotene clusters are disordered and rich in conformations.Single molecule extraction and cluster manipulation experiments indicate that intermolecular interactions of beta-carotene on Au(111) are stronger than molecule-substrate interactions.The mixtures of beta-caroteneand chlorophyll-a result in three regions of ordered self-assembled chlorophyll-a, mobile beta-carotene, and their disordered mixtures with a ratio of 43.6±7.8% to 56.4±10.1% (over 9 mixtures), respectively, with 56.0±10.1% of beta-carotene being trans, indicating beta-carotene preferential mixing with chlorophyll-a instead of its own beta-carotene clusters.The results of this dissertation provide information on single molecule level properties of beta-carotene for fundamental understanding as well as for applications in green nano-bio-technology, nano-medicine, molecular electronics, and energy harvesting.
Author: Timur Skeini
Institution: Ohio University
Language: English
Subfield: Physical and Theoretical Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2595742651