Optics and Biophysics
Our optics and biophysics faculty work on many interdisciplinary projects at the intersection of physics and biology. They also develop tools to improve health, environment, and safety. Students participating in research under the supervision of the optics and biophysics faculty members come from various science and engineering departments in addition to Physics and Astronomy. Therefore, students not only learn the science while they are engaged in their projects, but they also learn how to work with diverse teams. Through research participation, students greatly improve their laboratory, analytical, and computational skills, which become invaluable for their future studies and jobs.
About the Faculty
Siyu Li
Assistant Professor
Professor Li's research focuses on understanding biological assembly and membrane morphology through theoretical calculations and computational simulations. Dr. Li is particularly interested in how mechanical properties influence virus assembly, membrane budding, and elastic shell morphology. To explore these phenomena, Dr. Li has developed models to simulate the dynamics of macromolecular aggregation across various time scales to construct functional membrane structures. Dr. Li’s work has several applications, including the design of responsive shells to enhance the functionality of nanoreactors, packaging of macromolecules for gene delivery, controlled protein assembly, and the development of principles for assembling microcompartments for biochemical or energy applications.
Ertan Salik
Professor
Professor Salik develops fiberoptic biosensors for detection of proteins, viruses, and bacteria for applications in medical diagnosis, food safety, environmental monitoring, and biodefense. Dr. Salik’s lab is a truly interdisciplinary place filled by students majoring in various disciplines, such as, Physics, Biology, Electrical Engineering, and Mechanical Engineering. Dr. Salik’s lab is equipped with instruments and supplies to conduct his interdisciplinary research. Some of the instruments in the lab include multiple optics tables, numerous opto-mechanical and optical components, lasers, laser controllers, and optical spectrum analyzer (350-1700 nm), optical fiber components (couplers, amplifiers, polarization controllers, modulators, etc) , a 3D printer, oscilloscopes, function generators, a refrigerator/freezer, analytical balances, fume hood, microcentrifuge, hybridization oven.
Krishna Sigdel
Assistant Professor
Professor Sigdel uses Atomic force microscopy to probe the biomolecules in single molecule level. He studies the structure and dynamics of membrane proteins in near native environment and at physiological condition. Dr. Sigdel is currently developing his lab and will be installing an atomic force microscope to study membrane proteins. His research is fully interdisciplinary where student from Physics, Engineering, Chemistry/Biochemistry, and Biology can work. Dr. Sigdel also collaborates with Dr. Arthur Roberts from College of Pharmacy, University of Georgia, Athens to study membrane protein-drug interaction and Prof. Steve White at University of California Irvine for membrane protein-lipid interaction studies
Alex Small
Professor
Professor Small studies two simple questions: How much information is carried by a beam of light, and how can we use this knowledge to extract information from a live cell? Dr. Small studies the fundamental limits to superresolution microscopy, a family of fluorescence techniques that enable imaging of cells at nanometer resolution, revealing details not accessible to a conventional light microscope. As a theorist, Dr. Small’s work is mostly focused on understanding the theory that replaces Abbe’s diffraction limit, understanding the ways in which image analysis algorithms work with superresolution, and developing and benchmarking computational tools for superresolution. Additionally, Dr. Small has projects in light scattering (developing analytical and computational tools for studying scattering from particles in novel geometries) and percolation theory, focused on percolation in networks with novel structures applicable to new materials systems, and also applying some percolation insights to theoretical work on superresolution.
Li, S., Tresset, G., & Zandi, R. (2024). Switchable Conformation in Protein Subunits: Unveiling Assembly Dynamics of Icosahedral Viruses. arXiv:2409.00226
Olivia D Walsh, Leona Choi, and Krishna P. Sigdel, ‘’Effect of CM15 on supported lipid bilayer probed by atomic force microscopy’’ Membranes, 13, 864 (2023)
T. R. Matin, M. Utjesanovic, K.P. Sigdel, V. F. Smith, I. Kosztin, G. M. King; “Characterizing the locus of a peripheral membrane protein-lipid bilayer interaction underlying protein export activity in E. coli” Langmuir, 36, 2143-2152 (2020)
P. H. Nguyen, K. P. Sigdel, K. G. Shaefer, G.A.K. Mensah, G. M. King, A. G. Roberts; “The effects of anthracycline drugs on the conformational distribution of mouse P-glycoprotein explains their transportrate differences” Biochemical Pharmacology, 174, 113813 (2020)
M. Utjesanovic, T. R. Matin, K.P. Sigdel, G. M. King, I. Kosztin; “Multiple stochastic pathways in forced peptide-lipid membrane detachment” Scientific Reports, 9, 451 (2019)
K. P. Sigdel, L. A. Wilt, B.P. Marsh, A.G. Roberts, and G. M. King; “The conformation and dynamics of P-glycoprotein in a lipid bilayer investigated by atomic force microscopy” Biochemical Pharmacology, 156, 302 (2018)
Li, S., Roy, P., Travesset, A., & Zandi, R. (2018). Why large icosahedral viruses need scaffolding proteins. PNAS, 115(43), 10971-10976
Sigdel K.P., Pittman A.E., Matin T.R., King G.M. (2018) High-Resolution AFM-Based Force Spectroscopy. In: Lyubchenko Y. (eds) Nanoscale Imaging. Methods in Molecular Biology, vol 1814. Humana Press, New York, NY.
T. R. Matin, K.P. Sigdel, M. Utjesanovic, B. P. Marsh, F. Gallazzi, V. F. Smith, I. Kosztin and G. M. King, “Single-molecule peptide-lipid affinity assay reveals interplay between solution structure and partitioning” Langmuir, 33, 4057 (2017). DOI: 10.1021/acs.langmuir.7b00100
J. Miller, A. Castaneda, K. H. Lee, M. Sanchez, A. Ortiz , E. Almaz , Z. T. Almaz , S. Murinda , W.-J. Lin and E. Salik, Biconically Tapered Fiber Optic Probes for Rapid Label-Free Immunoassays, (2015) Biosensors, 5(2), 158-171
Small, A.R. and Stahlheber, S.P., The Role of Image Analysis Algorithms in Super-Resolution Localization Microscopy, (2014) in Advanced Fluorescence Microscopy, edited by Michael Conn and Anda Cornea, published by Elsevier, p. 227-242.
Yoo, T. Y., Tran, J., Stahlheber, S. P., Kaainoa, C. E., Djepang, K., and Small, A. R., Site percolation on lattices with low average coordination numbers, (2014) Journal of Statistical Mechanics: Theory and Experiment, P06014.
Small, A.R., Parthasarathy, Superresolution Localization Methods, (2014) Annual Review of Physical Chemistry, 65, 107-125.
Stahlheber, S.P., Small, A.R., Fluorophore Localization Algorithms for Superresolution Microscopy, (2014) Nature Methods, 11, 267-279.
K.P. Sigdel, J.S. Grayer, and G.M. King; “Three dimensional atomic force microscopy: Interaction force vector by direct observation of tip trajectory” Nano Letters, 13, 5106 (2013) DOI: 10.1021/nl403423p
Small, A. R., Fung, J., Manoharan, V.N., Generalization of the optical theorem for light scattering from a particle at a planar interface, (2013) Journal of the Optical Society of America A, 12, 2519-2525.
A. Small, Faster and more versatile tools for super-resolution fluorescence microscopy. (2012) Nature Methods, 9, 655
E. Salik, M. Medrano, G. Cohoon, J. Miller, C. Boyter, J. Koh, “SMS fiber sensor utilizing a few-mode fiber exhibits critical wavelength behavior,” (2012) IEEE Photonics Technology Letters. DOI:10.1109/LPT.2012.2184090
R. Starr, S. Stahlheber, A. Small, Fast maximum likelihood algorithm for localization of fluorescent molecules. (2012) Optics Letters, 37, 413.
E. Salik, “Quantitative investigation of Fresnel reflection coefficients by polarimetry,” (2012) American Journal of Physics, 80, 216. DOI: 10.1119/1.3672851
Z. Guo, C. Boyter, G. Cohoon, E. Salik, and W.-J. Lin, “Detection of Botulinum Neurotoxin by a Tapered Fiber Optic Biosensor,” (2011) GSTF International Journal of Bioinformatics and Biotechnology, 1, 1.
A. Small, Model of bleaching and acquisition for superresolution microscopy controlled by a single wavelength. (2011) Biomedical Optics Express, 2, 934.
E. Shore, A. Small, Optimal acquisition scheme for subwavelength localization microscopy of bleachable fluorophores. (2011) Optics Letters, 36, 289.
Triet Nguyen, Michael Mansell, Alex Small, Theoretical investigation of optical patterning of monolayers with subwavelength resolution. (2010) Physics Letters A, 374, 2681