+ Dilhara Jayarathna

I received my PhD in Chemistry from Carnegie Mellon University. I currently work as a Postdoctoral research associate at Taylor lab in the Department of Mechanical Engineering, Carnegie Mellon University. During my PhD, I worked on synthesis and characterization of peptides and peptide nucleic acid (PNA)s as nano-scaffolds to organize hetero-complexes for nanotechnology applications. In my postdoctoral work, I am taking the next step to design and develop mechanically and biological relevant nano-sensors based on nucleic acids. I received my BSc in Chemistry (minor Molecular Biology and Biotechnology) from University of Peradeniya, Sri Lanka.

Current Projects

  1. Design, synthesis and characterization of a DNA walker to validate the array formation on DNA origami tiles.
  2. PNA induced reversible conformational changes in DNA nanotubes/rings to develop nano-strain sensors.
  3. Maintainance of a Cell culture lab to develop an interface to teach new experimental techniques to beginners in tech-fields.

Previous Projects

  1. The Metal Coordination to Ligand Modified PNA Triplexes: PNA triplexes modified with ligands, that have affinities to metal ions were synthesized and characterized as nano-scale scaffolds to organized metal ions at predefined positions of triplexes. The findings from this project are in value to design hybrid inorganic-nucleic acid nanostructures.
  2. Peptide Nucleic Acid assisted Dimerization of Gold Nanocluster (AuNC)s: I described that AuNCs can be modified with a known number of ss-PNAs attached per AuNC and that these well-defined AuNC-PNA conjugates can be isolated. Mono-PNA modified AuNC conjugates were used to synthesise AuNC dimers assisted by complementary PNA hybridization. The long-term gold of the project is to use AuNCs-modified with different number of PNA strands as building blocks to created two- and three-dimensional hybrid-nanostructures in which AuNCs function as the vertices glued by PNA edges.
  3. Chirality based Probing of Plasmon-Dot Coupling: A larger extinction enhancement was achieved in the visible spectrum by using random Au nanoislands and a monolayer of colloidal quantum dot (CQD)s when chiral rather than achiral molecular linkers connect the Au nanoislands and the CQDs. Left- or right-handed gamma-PNA duplexes were used in this study. The findings from project may allow one to identify ways to design more sensitive and efficient photon detectors based on CQDs and may also offer a simple way to measure the circular dichroism of chiral monolayers.
  4. Spin-Dependent Mechanism of Charge Transfer through Helical Peptides: The charge transfer through left- and right-handed helical peptides was studied by electrochemistry and for the first time, a handedness-dependent asymmetry in rate constants for oxidation and reduction was observed. A novel model based on chiral induced spin selectivity (CISS)33 and the magnetization of the gold substrate was proposed to explain the observed asymmetry.

Scholarships and Awards

• Department Graduate Teaching Award, Carnegie Mellon University, 2016-2017

• Bronze medal at International Chemistry Olympiad, Tehran, Iran, 2011

• Bhikaji Framji Khan gold medal for Chemistry, University of Peradeniya, 2011

• Sultanbawa Prize for the best performance in Organic Chemistry, University of Peradeniya, 2011

• University Award for Academic Excellence, University of Peradeniya, 2011

• Scholarship for the overall best academic performance at University of Peradeniya, Public Trustee Department, Sri Lanka, 2006/2007

• Scholarship for the best performance in Biology, Alumni Association of University of Peradeniya, 2006/2007

Selected Publications

• Chiral molecules enhanced extinction ratio of quantum dots (QDs) coupled to random plasmonic structures, Langmuir, Accepted

• Chirality Dependent Charge Transfer Rate in Peptides: Submitted: Advanced Materials

• Metal Coordination to Ligand-Modified Peptide Nucleic Acid Triplexes: Submitted: ACS Inorganic Chemistry

• Peptide Nucleic Acid Assisted Dimerization of Gold Nanoclusters: manuscript in preparation

• Use of Carbohydrate Liquid Crystals as Emulsifiers, Proceedings in Peradeniya University Research Session (PURSE)

Presentations

Oral

• Metal Coordination to Ligand Modified Triplexes, ACS National Meeting, Philadelphia, 2016

• The Incorporation of Metal Complexes in Nucleic Acid Triplexes, ACS Regional Meeting, Pittsburgh, 2015

• The Incorporation of Metal Complexes in Nucleic Acid Triplexes, CNAST Mini Symposium, 2013

• Use of Carbohydrate Liquid Crystals as Emulsifiers, conference talk, Peradeniya University Research Session (PURSE), 2012

Posters

• The Incorporation of Metal Complexes in Nucleic Acid Triplexes, CNAST poster sessions, 2013, 2015, 2016

Contact Information

  • Contact me by email: djayarat@andrew.cmu.edu