The objective of this research effort is to understand the exciton dynamics and energy transfer within dye networks organized by and on DNA scaffolds.

Our work is multidisciplinary. Teams members synthesize dyes (e.g., modified cyanines) as well as DNA sequences and construct dye-labeled DNA origami networks. A wide range of instruments are employed to characterize these materials: chromatography, absorbance, photoluminescence, circular dichroism. 

Our group is interested in the delocalization of excitons and energy migration throughout these dye networks. Our research topics include:

• Energy transfer within the FRET and Coherent limits
• Vibronic coupling and exciton delocalization within dye dimers and aggregates
• System-bath effects on delocalization, coherence, and transport
• Suppression of quenching mechanisms

Our Laser Lab is used to interrogate these systems with a variety of static and time-resolved spectroscopic techniques. Our facilities includes

• UV/Vis/NIR absorption
• fluorescence
• fluorescence excitation spectra
• emission lifetimes via time-correlated single photon counting (TCSPC)
• femtosecond transient absorption spectroscopy
• emission lifetimes via femtosecond upconversion photoluminescence  spectroscopy
• cryostats compatible with time-resolved setups

Qualified candidates should possess or be completing a PhD in physics, chemistry, or related discipline with experience in time-resolved spectroscopy. Ultrafast spectroscopy or multidimensional spectroscopy is a plus, as is familiarity with photophysics in molecular systems, organic semiconductors, or other excitonic systems.

 

Recent publications:

Barclay, et al., J. Chem. Phys. 162, 174303 (2025) - 2DES of H- and J-dimers

Pascual, et al., Nanoscale Horizons 9, 2334 (2024) - Heterodimers of modified Cy5 dyes

Chowdhury, et al., J. Phys. Chem. Lett. 12, 2782 (2022) – FRET and Quenching in Cy5-Cy5.5 heterodimer

Cunningham, et al., Adv. Opt. Mater. 9, 2100884 (2021) – Comparing interacting vs redundant FRET pathways 

Sohail, et al., Chem Sci 11, 8546 (2020) – 2DES of Vibronic Coherences

Cunningham, et al., J. Phys. Chem. B. 124, 8042 (2020) – doubly excited states in J-dimers

Cunningham, et al., J. Phys. Chem. B. 122, 5020 (2018) – strongly-coupled Cy3 homodimers

key words

DNA Origami, FRET, excitons, vibronic, dimers, aggregates, coherence, spectroscopy, time-resolved

Citizenship:  Open to U.S. citizens and permanent residents

Level:  Open to Postdoctoral applicants

Additional Benefits

Relocation

Awardees who reside more than 50 miles from their host laboratory and remain on tenure for at least six months are eligible for paid relocation to within the vicinity of their host laboratory.

Health insurance

A group health insurance program is available to awardees and their qualifying dependents in the United States.