Postdoctoral Researchers

Christopher W. Leishman, PhD

Email: cleishman(at)

Dr. Leishman grew up in Albuquerque, New Mexico. He studied physics and applied math at the University of New Mexico, where he became fascinated with quantum dynamics in biological energy transport processes. After graduating, he moved to Oregon, earning an additional bachelor’s degree (Chemistry) at Portland State University while performing computational modeling of sensitizing dyes and photoactive polymers for solar cells in the research group of Prof. Carl Wamser. In July 2016, he earned his Ph.D. in physical chemistry from the Department of Chemistry of Washington State University in Pullman, Washington, under the mentorship of Prof. Jeanne L. McHale. In his doctoral research, he coordinated resonance Raman spectroscopy with nanoscale imaging to distill insights into relationships between structure and optical properties of supramolecular porphyrin aggregates. He published the findings from these investigations in an interlinked series of three first author papers.

Dr. Leishman joined Prof. Eisele’s research group as a postdoctoral researcher in September 2016 at the City College of New York, where he is working on structural and optical studies of energy and charge transfer dynamics in composite nanoscale systems including hybrid excitonic and plasmonic materials. He is driven by a vision to engage cutting-edge optical spectroscopy, microscopy and theoretical investigations to enable future advances in sustainable energy.


Three Selected Publications:

1. Leishman, C. W.; McHale, J. L. Light-Harvesting Properties and Morphology of Porphyrin Nanostructures Depend on Ionic Species Inducing Aggregation. The Journal of Physical Chemistry C 2015, 119, 28167–28181.DOI: 10.1021/acs.jpcc.5b08849

2. Leishman, C. W.; McHale, J. L. Illuminating Excitonic Structure in Ion-Dependent Porphyrin Aggregates with Solution Phase and Single-Particle Resonance Raman Spectroscopy. The Journal of Physical Chemistry C 2016, 120, 12783–12795. DOI: 10.1021/acs.jpcc.6b00867

3. Leishman, C. W.; McHale, J. L. Morphologically-Determined Excitonic Properties of Porphyrin Aggregates in Alcohols with Variable Acidity. The Journal of Physical Chemistry C 2016. DOI: 10.1021/acs.jpcc.6b04998


Nikunjkumar Visaveliya, PhD

Email: nvisaveliya(at)

Dr. Nikunjkumar Visaveliya was born in Devkigalol, India. He earned his B.Sc. in Chemistry and M.Sc. in Organic Chemistry both at the Sardar Patel University, Gujarat, India. After completing his M.Sc., he moved to National Chemical Laboratory, Pune, India where he worked as a research project assistant under Dr. BLV Prasad on the synthesis of different bio-surfactants and their applications. He then joined Prof. J. Michael Koehler’s group at the Technical University of Ilmenau, Germany in order to obtain his PhD. In Prof. Koehler’s group, Nikunjkumar gained extensive expertise in state of the art microfluidic nanosynthesis. He applied these microfluidic techniques to synthesize different types of multi-functional nanoparticles (organic as well as inorganic) with a wide variation of parameters such as size, shape, assembly, and composition for different functional applications. During his PhD career, Nikunjkumar published 17 manuscripts in peer reviewed journals, of which he is first author of 11 publications.

In November 2016, Dr. Visaveliya joined Prof. Eisele’s research group at the City College of New York as a postdoctoral researcher. His research interests concern nanomaterials for light-matter interactions. Specifically, he is interested in utilizing microfluidics for supramolecular self-assembly as well as for polymeric nanomaterials and novel nanocomposites for optical and biomedical applications. Nikunjkumar is passionate about pushing microfluidics forward to new frontiers.

Three Selected Publications:

1. N. Visaveliya and J. M. Köhler; “Microfluidic Assisted Synthesis of Multipurpose Polymer Nanoassembly Particles for Fluorescence, LSPR, and SERS Activities”, Small, 11, 6435–6443 (2015) (Inside Cover Article).

2. N. Visaveliya, S. Lenke and J. M. Köhler; “Composite Sensor Particles for Tuned SERS Sensing: Microfluidic Synthesis, Properties and Applications”, ACS Appl. Mater. Interfaces, 7 (20), 10742-10754 (2015).

3. N. Visaveliya and J. M. Köhler; “Single-Step Microfluidic Synthesis of Various Non-Spherical Polymer Nanoparticles via in-Situ Assembling: Dominating Role of Polyelectrolytes Molecules, ACS Appl. Mater. Interfaces, 6 (14), 11254-11264 (2014).