New Directions for Photonic-Based Sensors and Analytical Tools

ChEMS Seminar

Speaker: Dr. Donald J. Sirbuly 

Assistant Professor

Department of NanoEngineering and Materials Science and Engineering Program



Photonics continues to be an active area of research for various fields including communications, medicine and energy conversion. Optical-based platforms have also been a cornerstone for many analytical tools used to sense and characterize individual molecular and biochemical systems. For example, fine molecular analysis of conformational changes, intramolecular distances, and/or adhesion forces are typically carried out by methods such as optical tweezers, scan probe technologies, Förster energy transfer schemes, or other molecular ruler platforms. Since quantitative measurements at the molecular level continue to be at the core of biological and materials R&D, it will be crucial to develop novel sensing architectures that can be inserted directly into systems for in situ diagnostics and/or be engineered to rapidly measure molecular interactions.  In this talk, I will present some of our recent work on subwavelength optical waveguides and show how the evanescent field surrounding the fiber can be used to design intricate sensors and analytical probes. I will also show how light-matter interactions occurring within the evanescent field can be leveraged to detect molecular displacements at the angstrom level. The simple design of obtaining distance feedback makes this an exciting platform for new force sensing devices, imaging technologies and high-throughput molecular analysis.



Dr. Sirbuly is an Assistant Professor in the Department of NanoEngineering and Materials Science and Engineering Program at UCSD. He received his Ph.D. in chemistry from UCSB in 2003 under the supervision of Prof. Steven Buratto. His graduate work was on the synthesis and photophysical properties of nanocrystalline silicon. He carried out postdoctoral research at UC Berkeley under the supervision of Prof. Peidong Yang where he worked on the optical and electronic characterization of one-dimensional semiconductor nanostructures. He was then awarded the Harold C. Graboske Jr. Fellowship at Lawrence Livermore National Laboratory (LLNL) in 2006 and later become a staff scientist at LLNL in 2008. His work at LLNL was on the development of novel chemical and biological sensors. After joining UCSD in 2009 he has been interested in low-dimensional nanostructures for applications in sensing, biodiagnostics, energy conversion, and imaging. He is a recipient of the NSF CAREER Award and the Hellman Fellowship at UCSD.