Judy Su

Interests

Research

Optical biosensors, Optical microcavities, Whispering gallery modes, Integrated optics, Chemical threat sensing, Microfluidics, Optofluidics, Liquid biopsies, Single molecule dynamics/detection, Bioimaging, Biophotonics, Medical diagnostics, Clean competition, Alzheimer’s diagnostics and prognostics, Environmental monitoring.

Teaching

Biomedical instrumentation, Biophotonics, Biomedical optics

Courses

Scholarly Contributions

Journals/Publications

• Suebka, S., Gin, A., & Su, J. (2025). Frequency locked whispering evanescent resonator (FLOWER) for biochemical sensing applications. Nature protocols.
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  Sensitive, rapid and label-free biochemical sensors are needed for many applications. In this protocol, we describe biochemical detection using FLOWER (frequency locked optical whispering evanescent resonator)-a technique that we have used to detect single protein molecules in aqueous solution as well as exosomes, ribosomes and low part-per-trillion concentrations of volatile organic compounds. Whispering gallery mode microtoroid resonators confine light for extended time periods (hundreds of nanoseconds). When light circulates within the resonator, a portion of the electromagnetic field extends beyond the cavity, forming an evanescent field. This field interacts with bound analytes resulting in a change in the cavity's effective refractive index, which can be tracked by monitoring shifts in the resonance wavelength. The surface of the microtoroid can be functionalized to respond specifically to an analyte or biochemical interaction of interest. The frequency-locking feature of frequency locked optical whispering evanescent resonator means that the instruments respond to perturbations in the surface by very rapidly finding the new resonant frequency. Here we describe microtoroid fabrication (4-6 h), how to couple light into these devices using tapered optical fibers (20-40 min) and procedures for coupling antibodies as well as G-protein coupled receptors to the microtoroid's surface (from 1 h to 1 d depending on the target analyte). In addition, we describe our liquid handling perfusion system as well as the use of a rotary selector valve and custom fluidic chamber to optimize sample delivery. Step-by-step details on how to perform biosensing experiments and analyze the data are described; this takes 1-2 d.
• Gin, A., Nguyen, P. D., Melzer, J. E., Li, C., Strzelinski, H., Liggett, S. B., & Su, J. (2024). Label-free, real-time monitoring of membrane binding events at zeptomolar concentrations using frequency-locked optical microresonators. Nature communications, 15(1), 7445.
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  G-protein coupled receptors help regulate cellular function and communication, and are targets of small molecule drug discovery efforts. Conventional techniques to probe these interactions require labels and large amounts of receptor to achieve satisfactory sensitivity. Here, we use frequency-locked optical microtoroids for label-free characterization of membrane interactions in vitro at zeptomolar concentrations for the kappa opioid receptor and its native agonist dynorphin A 1-13, as well as big dynorphin (dynorphin A and dynorphin B) using a supported biomimetic membrane. The measured affinity of the agonist dynorphin A 1-13 to the κ-opioid receptor was also measured and found to be 3.1 nM. Radioligand assays revealed a dissociation constant in agreement with this value (1.1 nM). The limit of detection for the κOR/DynA 1-13 was calculated as 180 zM. The binding of Cholera Toxin B-monosialotetrahexosyl ganglioside was also monitored in real-time and an equilibrium dissociation constant of 1.53 nM was found. Our biosensing platform provides a method for highly sensitive real-time characterization of membrane embedded protein binding kinetics that is rapid and label-free, for drug discovery and toxin screening among other applications.
• Gin, A., Nguyen, P., Serrano, G., Alexander, G. E., & Su, J. (2024). Towards early diagnosis and screening of Alzheimer???s disease using frequency locked whispering gallery mode microtoroids. npj Biosensing, 1(1), 9.
• Hao, S., & Su, J. (2024). Whispering gallery mode optical resonators for biological and chemical detection: current practices, future perspectives, and challenges. Reports on progress in physics. Physical Society (Great Britain), 88(1).
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  Sensors are important for a wide variety of applications include medical diagnostics and environmental monitoring. Due to their long photon confinement times, whispering gallery mode (WGM) sensors are among the most sensitive sensors currently in existence. We briefly discuss what are WGM sensors, the principles of WGM sensing, and the history of the field, beginning with Mie theory. We discuss recent work in the field on using these WGM resonators as sensors, focusing particularly on biological and chemical sensing applications. We discuss how sensorgrams are acquired and fundamental measurement limits. In addition, we discuss how to interpret binding curves and extract physical parameters such as binding affinity constants. We discuss the controversy surrounding single-molecule detection and discuss hybrid WGM nanoparticle sensors. In addition, we place these sensors in context with others sensing technologies both labeled and label-free. Finally, we discuss what we believe are the most promising applications for these devices, outline remaining challenges, and provide an outlook for the future.
• Hao, S., Guthrie, B., Kim, S. K., Balanda, S., Kubicek, J., Murtaza, B., Khan, N. A., Khakbaz, P., Su, J., & Goddard, W. A. (2024). Steviol rebaudiosides bind to four different sites of the human sweet taste receptor (T1R2/T1R3) complex explaining confusing experiments. Communications chemistry, 7(1), 236.
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  Sucrose provides both sweetness and energy by binding to both Venus flytrap domains (VFD) of the heterodimeric sweet taste receptor (T1R2/T1R3). In contrast, non-caloric sweeteners such as sucralose and aspartame only bind to one specific domain (VFD2) of T1R2, resulting in high-intensity sweetness. In this study, we investigate the binding mechanism of various steviol glycosides, artificial sweeteners, and a negative allosteric modulator (lactisole) at four distinct binding sites: VFD2, VFD3, transmembrane domain 2 (TMD2), and TMD3 through binding experiments and computational docking studies. Our docking results reveal multiple binding sites for the tested ligands, including the radiolabeled ligands. Our experimental evidence demonstrates that the C20 carboxy terminus of the Gα protein can bind to the intracellular region of either TMD2 or TMD3, altering GPCR affinity to the high-affinity state for steviol glycosides. These findings provide a mechanistic understanding of the structure and function of this heterodimeric sweet taste receptor.
• Hao, S., Suebka, S., & Su, J. (2024). Single 5-nm quantum dot detection via microtoroid optical resonator photothermal microscopy. Light, science & applications, 13(1), 195.
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  Label-free detection techniques for single particles and molecules play an important role in basic science, disease diagnostics, and nanomaterial investigations. While fluorescence-based methods are tools for single molecule detection and imaging, they are limited by available molecular probes and photoblinking and photobleaching. Photothermal microscopy has emerged as a label-free imaging technique capable of detecting individual nanoabsorbers with high sensitivity. Whispering gallery mode (WGM) microresonators can confine light in a small volume for enhanced light-matter interaction and thus are a promising ultra-sensitive photothermal microscopy platform. Previously, microtoroid optical resonators were combined with photothermal microscopy to detect 250 nm long gold nanorods and 100 nm long polymers. Here, we combine microtoroids with photothermal microscopy to spatially detect single 5 nm diameter quantum dots (QDs) with a signal-to-noise ratio exceeding 10. Photothermal images were generated by point-by-point scanning of the pump laser. Single particle detection was confirmed for 18 nm QDs by high sensitivity fluorescence imaging and for 5 nm QDs via comparison with theory. Our system demonstrates the capability to detect a minimum heat dissipation of 0.75 pW. To achieve this, we integrated our microtoroid based photothermal microscopy setup with a low amplitude modulated pump laser and utilized the proportional-integral-derivative controller output as the photothermal signal source to reduce noise and enhance signal stability. The heat dissipation of these QDs is below that from single dye molecules. We anticipate that our work will have application in a wide variety of fields, including the biological sciences, nanotechnology, materials science, chemistry, and medicine.
• Kim, S., Suebka, S., Gin, A., Nguyen, P., Tang, Y., Su, J., & Goddard, W. (2024). Methotrexate Inhibits the Binding of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Receptor Binding Domain to the Host-Cell Angiotensin-Converting Enzyme-2 (ACE-2) Receptor. ACS Pharmacology & Translational Science, 7(2), 348-362.
• Su, T. J., Mcleod, E., & Suebka, S. (2024). Ultra-high-Q free-space coupling to microtoroid resonators. Light: Science & Applications, 13(1), 75. doi:10.1038/s41377-024-01418-0
• Suebka, S., McLeod, E., & Su, J. (2024). Ultra-high-Q free-space coupling to microtoroid resonators. Light, science & applications, 13(1), 75.
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  Whispering gallery mode (WGM) microtoroid resonators are one of the most sensitive biochemical sensors in existence, capable of detecting single molecules. The main barrier for translating these devices out of the laboratory is that light is evanescently coupled into these devices though a tapered optical fiber. This hinders translation of these devices as the taper is fragile, suffers from mechanical vibration, and requires precise positioning. Here, we eliminate the need for an optical fiber by coupling light into and out from a toroid via free-space coupling and monitoring the scattered resonant light. A single long working distance objective lens combined with a digital micromirror device (DMD) was used for light injection, scattered light collection, and imaging. We obtain Q-factors as high as with this approach. Electromagnetically induced transparency (EIT)-like and Fano resonances were observed in a single cavity due to indirect coupling in free space. This enables improved sensing sensitivity. The large effective coupling area (~10 μm in diameter for numerical aperture = 0.14) removes the need for precise positioning. Sensing performance was verified by combining the system with the frequency locked whispering evanescent resonator (FLOWER) approach to perform temperature sensing experiments. A thermal nonlinear optical effect was examined by tracking the resonance through FLOWER while adjusting the input power. We believe that this work will be a foundation for expanding the implementation of WGM microtoroid resonators to real-world applications.
• Xu, Y., Stanko, A. M., Cerione, C. S., Lohrey, T. D., McLeod, E., Stoltz, B. M., & Su, J. (2024). Low Part-Per-Trillion, Humidity Resistant Detection of Nitric Oxide Using Microtoroid Optical Resonators. ACS Applied Materials & Interfaces, 16(4), 5120-5128.
• Young Yang, M., Duy Mac, K., Strzelinski, H. R., Hoffman, S. A., Kim, D., Kim, S. K., Su, J., Liggett, S. B., & Goddard, W. A. (2024). Agonist activation to open the Gα subunit of the GPCR-G protein precoupled complex defines functional agonist activation of TAS2R5. Proceedings of the National Academy of Sciences of the United States of America, 121(48), e2409987121.
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  G protein-coupled receptors (GPCRs) regulate multiple cellular responses and represent highly successful therapeutic targets. The mechanisms by which agonists activate the G protein are unclear for many GPCR families, including the bitter taste receptors (TAS2Rs). We ascertained TAS2R5 properties by live cell-based functional assays, direct binding affinity measurements using optical resonators, and atomistic molecular dynamics simulations. We focus on three agonists that exhibit a wide range of signal transduction in cells despite comparable ligand-receptor binding energies derived from direct experiment and computation. Metadynamics simulations revealed that the critical barrier to activation is ligand-induced opening of the G protein between the α-helical (AH) and Ras-like domains of Gα subunit from a precoupled TAS2R5-G protein state to the fully activated state. A moderate agonist opens the AH-Ras cleft from 22 Å to 31 Å with an energy gain of -4.8 kcal mol, making GDP water-exposed for signaling. A high-potency agonist had an energy gain of -11.1 kcal mol. The low-potency agonist is also exothermic for Gα opening, but with an energy gain of only -1.4 kcal mol. This demonstrates that TAS2R5 agonist-bound functional potencies are derived from energy gains in the transition from a precoupled complex at the level of Gα opening. Our experimental and computational study provides insights into the activation mechanism of signal transduction that provide a basis for rational design of new drugs.
• Choi, G., & Su, J. (2023). Impact of stimulated Raman scattering on dark soliton generation in a silica microresonator. Journal of Physics: Photonics, 5(1), 014001.
• Luu, G. T., Ge, C., Tang, Y., Li, K., Cologna, S. M., Godwin, A. K., Burdette, J. E., Su, J., & Sanchez, L. M. (2023). An Integrated Approach to Protein Discovery and Detection From Complex Biofluids. Molecular & Cellular Proteomics, 22(7).
• Choi, G., Gin, A., & Su, J. (2022). Optical frequency combs in aqueous and air environments at visible to near-IR wavelengths. Opt. Express, 30(6), 8690-8699.
• Li, C., Lohrey, T., Nguyen, P., Min, Z., Tang, Y., Ge, C., Sercel, Z. P., McLeod, E., Stoltz, B. M., & Su, J. (2022). Part-per-Trillion Trace Selective Gas Detection Using Frequency Locked Whispering-Gallery Mode Microtoroids. ACS Applied Materials & Interfaces, 14(37), 42430-42440.
• Dell'Olio, F., Su, J., Huser, T., Sottile, V., Cortés-Hernández, L. E., & Alix-Panabières, C. (2021). Photonic Technologies for Liquid Biopsies: Recent Advances and Open Research Challenges. Laser & Photonics Reviews, 15(1), 2000255.
• Suebka, S., Nguyen, P., Gin, A., & Su, J. (2021). How Fast It Can Stick: Visualizing Flow Delivery to Microtoroid Biosensors. ACS Sensors, 6(7), 2700-2708.
• Chen, L., Li, C., Liu, Y., Su, J., & McLeod, E. (2020). Three-Dimensional Simulation of Particle-Induced Mode Splitting in Large Toroidal Microresonators. Sensors, 20(18).
• Dell'Olio, F., Su, T. J., Huser, T., Sottile, V., Cortés‐Hernández, L. E., & Alix‐Panabières, C. (2020). Photonic technologies for liquid biopsies: recent advances and open research challenges. Laser & Photonics Reviews. doi:https://doi.org/10.1002/lpor.202000255
• Hao, S., & Su, J. (2020). Noise-Induced Limits of Detection in Frequency Locked Optical Microcavities. Journal of Lightwave Technology, 38(22), 6393-6401.
• Chen, L., Li, C., Liu, Y., Su, J., & McLeod, E. (2019). Simulating robust far-field coupling to traveling waves in large three-dimensional nanostructured high-Q microresonators. Photon. Res., 7(9), 967-976.
• Li, C., Chen, L., McLeod, E., & Su, J. (2019). Dark mode plasmonic optical microcavity biochemical sensor. Photon. Res., 7(8), 939-947.
• Mcleod, E., Su, T. J., Liu, Y., Li, C., & Chen, L. (2019). Simulating robust far-field coupling to travelling waves in large three-dimensional nanostructured high-Q microresonators. Photonics Research, 7(9), 967-976.
• Nguyen, P., Zhang, X., & Su, J. (2019). One-Step Controlled Synthesis of Size-Tunable Toroidal Gold Particles for Biochemical Sensing. ACS Applied Nano Materials, 2(12), 7839-7847.
• Ozgur, E., Roberts, K. E., Ozgur, E. O., Gin, A. N., Bankhead, J. R., Wang, Z., & Su, J. (2019). Ultra-sensitive detection of human chorionic gonadotropin using frequency locked microtoroid optical resonators. Analytical Chemistry.
• Su, T. J., Mcleod, E., Chen, L., & Li, C. (2019). Dark mode plasmonic optical microcavity biochemical sensor. Photonics Research, 7(8), 939-947.
• Su, J. (2018). Portable and sensitive air pollution monitoring. Light: Science & Applications, 7(1), 3.
• Su, J. (2017). Label-Free Biological and Chemical Sensing Using Whispering Gallery Mode Optical Resonators: Past, Present, and Future. Sensors (Basel, Switzerland), 17(3).
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  Sensitive and rapid label-free biological and chemical sensors are needed for a wide variety of applications including early disease diagnosis and prognosis, the monitoring of food and water quality, as well as the detection of bacteria and viruses for public health concerns and chemical threat sensing. Whispering gallery mode optical resonator based sensing is a rapidly developing field due to the high sensitivity and speed of these devices as well as their label-free nature. Here, we describe the history of whispering gallery mode optical resonator sensors, the principles behind detection, the latest developments in the fields of biological and chemical sensing, current challenges toward widespread adoption of these devices, and an outlook for the future. In addition, we evaluate the performance capabilities of these sensors across three key parameters: sensitivity, selectivity, and speed.
• Su, J., Goldberg, A., & Stoltz, B. M. (2016). Label-free detection of single nanoparticles and biological molecules using microtoroid optical resonators. LIGHT-SCIENCE & APPLICATIONS, 5.
• Su, T. J. (2016). Reply to "Comment on 'Label-Free Single Exosome Detection Using Frequency-Locked Microtoroid Optical Resonators'". ACS PHOTONICS, 3(4), 718-718.
• Su, J. (2015). Label-free Single Molecule Detection Using Microtoroid Optical Resonators. Journal of visualized experiments : JoVE, e53180.
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  Detecting small concentrations of molecules down to the single molecule limit has impact on areas such as early detection of disease, and fundamental studies on the behavior of molecules. Single molecule detection techniques commonly utilize labels such as fluorescent tags or quantum dots, however, labels are not always available, increase cost and complexity, and can perturb the events being studied. Optical resonators have emerged as a promising means to detect single molecules without the use of labels. Currently the smallest particle detected by a non-plasmonically-enhanced bare optical resonator system in solution is a 25 nm polystyrene sphere(1). We have developed a technique known as Frequency Locking Optical Whispering Evanescent Resonator (FLOWER) that can surpass this limit and achieve label-free single molecule detection in aqueous solution(2). As signal strength scales with particle volume, our work represents a > 100x improvement in the signal to noise ratio (SNR) over the current state of the art. Here the procedures behind FLOWER are presented in an effort to increase its usage in the field.
• Su, T. J. (2015). Label-Free Single Exosome Detection Using Frequency-Locked Microtoroid Optical Resonators. ACS PHOTONICS, 2(9), 1241-1245.
• Su, J., Brau, R. R., Jiang, X., Whitesides, G. M., Lange, M. J., & So, P. T. (2007). Geometric confinement influences cellular mechanical properties II -- intracellular variances in polarized cells. Molecular & cellular biomechanics : MCB, 4(2), 105-18.
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  During migration, asymmetrically polarized cells achieve motion by coordinating the protrusion and retraction of their leading and trailing edges, respectively. Although it is well known that local changes in the dynamics of actin cytoskeleton remodeling drive these processes, neither the cytoskeletal rheological properties of these migrating cells are well quantified nor is it understand how these rheological properties are regulated by underlying molecular processes. In this report, we have used soft lithography to create morphologically polarized cells in order to examine rheological differences between the front and rear zone of an NIH 3T3 cell posed for migration. In addition, we trapped superparamagnetic beads with optical tweezers and precisely placed them at specific locations on the immobilized cells. The beads were then allowed to endocytose overnight before magnetic tweezers experiments were performed to measure the local rheological properties of the leading and trailing edges. Our results indicate that the leading edge has an approximately 1.9 times higher shear modulus than the trailing edge and that this increase in shear modulus correlates with a greater density of filamentous actin, as measured by phalloidin-staining observed through quantitative 3D microscopy.
• Su, J., Jiang, X., Welsch, R., Whitesides, G. M., & So, P. T. (2007). Geometric confinement influences cellular mechanical properties I -- adhesion area dependence. Molecular & cellular biomechanics : MCB, 4(2), 87-104.
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  Interactions between the cell and the extracellular matrix regulate a variety of cellular properties and functions, including cellular rheology. In the present study of cellular adhesion, area was controlled by confining NIH 3T3 fibroblast cells to circular micropatterned islands of defined size. The shear moduli of cells adhering to islands of well defined geometry, as measured by magnetic microrheometry, was found to have a significantly lower variance than those of cells allowed to spread on unpatterned surfaces. We observe that the area of cellular adhesion influences shear modulus. Rheological measurements further indicate that cellular shear modulus is a biphasic function of cellular adhesion area with stiffness decreasing to a minimum value for intermediate areas of adhesion, and then increasing for cells on larger patterns. We propose a simple hypothesis: that the area of adhesion affects cellular rheological properties by regulating the structure of the actin cytoskeleton. To test this hypothesis, we quantified the volume fraction of polymerized actin in the cytosol by staining with fluorescent phalloidin and imaging using quantitative 3D microscopy. The polymerized actin volume fraction exhibited a similar biphasic dependence on adhesion area. Within the limits of our simplifying hypothesis, our experimental results permit an evaluation of the ability of established, micromechanical models to predict the cellular shear modulus based on polymerized actin volume fraction. We investigated the "tensegrity", "cellular-solids", and "biopolymer physics" models that have, respectively, a linear, quadratic, and 5/2 dependence on polymerized actin volume fraction. All three models predict that a biphasic trend in polymerized actin volume fraction as a function of adhesion area will result in a biphasic behavior in shear modulus. Our data favors a higher-order dependence on polymerized actin volume fraction. Increasingly better experimental agreement is observed for the tensegrity, the cellular solids, and the biopolymer models respectively. Alternatively if we postulate the existence of a critical actin volume fraction below which the shear modulus vanishes, the experimental data can be equivalently described by a model with an almost linear dependence on polymerized actin volume fraction; this observation supports a tensegrity model with a critical actin volume fraction.
• Pelet, S., Previte, M., Kim, D., Kim, K. H., Su, T. J., & So, P. (2006). Frequency domain lifetime and spectral imaging microscopy. MICROSCOPY RESEARCH AND TECHNIQUE, 69(11), 861-874.

Proceedings Publications

• Hao, S., & Su, J. (2024, 2024). Single 5-nm particle photothermal microscopy with microtoroid optical resonators. In Technical Digest Series, SF3B.2.
• Su, T. J., Mcleod, E., & Suebka, S. (2024). Ultra-high Q values for microtoroid resonators with free space coupling. In Conference on Lasers and Electro-Optics, ATu3B.2.
• Suebka, S., Mcleod, E., & Su, J. (2024, 2024). Ultra-high Q values for microtoroid resonators with free space coupling. In Technical Digest Series, ATu3B.2.
• McLeod, E., Melzer, J. E., Suebka, S., Chen, L., Li, C., & Su, J. (2023, 2023/6/14). Free-space coupling to microtoroid optical resonator chemosensors. In Free-space coupling to microtoroid optical resonator chemosensors, PC12541, PC1254102.
• Su, J. (2023, 2023). Ultra-Sensitive, Selective, and Label-Free Optical Sensing for Fundamental Science, Environmental Monitoring, and Translational Medicine. In Technical Digest Series, FM6E.1.
• Hao, S., & Su, J. (2021, 2021/3/11). Frequency-locked optical microresonator noise analysis. In Frequency-locked optical microresonator noise analysis, 11635.
• Li, C., Lohrey, T., Nguyen, P., Min, Z., Stoltz, B., & Su, J. (2021, 2021/3/5). Part-per-trillion trace gas detection using frequency-locked whispering gallery mode microtoroids. In Part-per-trillion trace gas detection using frequency-locked whispering gallery mode microtoroids, 11689.
• Su, J. (2021, 2021). Ultra-Sensitive and Selective Detection of DNA and Protein Biomarkers Using Frequency-Locked Microtoroid Optical Resonators. In OSA Technical Digest, SM3O.1.
• Suebka, S., Nguyen, P., Gin, A., & Su, J. (2021, 2021/3/5). Flow visualization of analyte transport to microtoroid optical resonators. In Flow visualization of analyte transport to microtoroid optical resonators, 11637.
• McLeod, E., Su, J., Nguyen, P., & Melzer, J. E. (2020, September). Assembly of Nanophotonic Structures Using Optical Tweezers. In Frontiers in Optics, FTu6B. 5.
• Gin, A., Nguyen, P., Ozgur, E., & Su, J. (2019, 2019). Label-free Ultrasensitive Detection of Amyloid-β Using Lipid-Functionalized Microtoroid Optical Resonators for Early Diagnosis of Alzheimer’s Disease. In OSA Technical Digest, DW1B.5.
• Li, C., Chen, L., McLeod, E., & Su, J. (2019, 2019). Plasmonic Dark Modes for Enhanced Microcavity Biosensing. In The Optical Society, OW2D.2.
• Mcleod, E., Su, T. J., Liu, Y., Li, C., & Chen, L. (2019, July). Simulating Travelling Waves in Large 3D Whispering Gallery Mode Resonators Decorated with Plasmonic Nanoparticles. In Advanced Photonics Congress, IW1A.4.
• Nguyen, P., Gin, A., & Su, J. (2019, 2019). Detection of membrane binding events using microtoroid optical resonators. In OSA Technical Digest, DW2B.1.
• Ozgur, E., Roberts, K. E., Ozgur, E. O., Gin, A. N., Bankhead, J. R., Wang, Z., & Su, J. (2019, 2019). Frequency-locked Optical Whispering Evanescent Resonators for Ultra-Sensitive Doping Detection in Urine. In OSA Technical Digest, DW1B.4.
• Su, J. (2019, 2019). Ultra-Sensitive and Selective Biomolecular Detection Using Frequency-Locked Microtoroid Optical Resonators. In OSA Technical Digest, ITh3A.4.
• Su, T. J., Mcleod, E., Chen, L., & Li, C. (2019, April). Plasmonic Dark Modes for Enhanced Microcavity Biosensing. In Biophotonics Congress: Optics in the Life Sciences, OW2D.2.
• Li, C., Teimourpour, M., Mcleod, E., Su, T. J., Su, T. J., Mcleod, E., Teimourpour, M., & Li, C. (2018, April). Enhanced Whispering Gallery Mode Sensors. In SPIE Defense and Commercial Sensing.
• Su, T. J. (1997, June). On the Fusion of a Line Plume into a Large Scale Vortex Cloud. In American Society of Mechanical Engineers Fluids Engineering Division Summer Meeting, FEDSM-97-170-3672.

Presentations

• Mcleod, E., Su, T. J., & Suebka, S. (2024). Free space coupling to ultra-high Q microtoroids for biosensing experiments. Photonics West. San Francisco, CA: SPIE.
• Mcleod, E., Su, T. J., Suebka, S., & Sharma, K. (2024). Nanofabrication on optical resonators using optical tweezers. Optics + Photonics. San Diego: SPIE.
• Stoltz, B. M., Mcleod, E., Lohrey, T., Cerione, C. S., Xu, Y., & Su, T. J. (2024). Part-per-trillion, selective, and robust nitric oxide sensing using FLOWER. SPIE Defense + Commercial Sensing. National Harbor, MD: SPIE.
• Su, T. J., Mcleod, E., & Suebka, S. (2024). Ultra-high Q values for microtoroid resonators with free space coupling. Conference on Lasers and Electro-Optics (CLEO). Charlotte, NC: Optica.
• Su, T. J., Stoltz, B., Cerione, C., Stanko, A., Xu, Y., Suebka, S., Sharma, K., & Mcleod, E. (2024). Nanoparticle-enhanced microtoroid optical chemosensors for sensitive and efficient monitoring. Chemical and Biological Defense Science & Technology Conference. Ft. Lauderdale, FL: Defense Threat Reduction Agency (DTRA).
• Su, T. J., Suebka, S., Sharma, K., & Mcleod, E. (2024). Toward portable nanostructured whispering gallery mode chemical sensors accessed via free-space coupling. SPIE Defense + Commercial Sensing. National Harbor, MD: SPIE.
• Suebka, S., Mcleod, E., & Su, T. J. (2024). Free space coupling to ultra-high Q microtoroids for biosensing experiments. SPIE Photonics West.
• Hao, S., Suebka, S., & Su, T. J. (2023). Single particle material characterization using microtoroid optical resonators. SPIE Photonics West.
• Mcleod, E., Melzer, J. E., Suebka, S., Chen, L., Li, C., & Su, T. J. (2023). Free-space coupling to microtoroid optical resonator chemosensors. SPIE, Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) Sensing XXIV.
• Su, J., Li, C., Chen, L., Suebka, S., Melzer, J. E., & Mcleod, E. (2023). Free-space coupling to microtoroid optical resonator chemosensors. Defense + Commercial Sensing. Orlando: SPIE.
• Su, T. J. (2023). Part-per-trillion selective gas sensing using FLOWER. PIE, Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) Sensing XXIV.
• Su, T. J. (2023). Ultra-sensitive, selective, and label-free optical sensing for fundamental science, environmental monitoring, and translational medicine. Caltech Electrical Engineering Devices Seminar.
• Su, T. J. (2023). Ultra-sensitive, selective, and label-free optical sensing for fundamental science, environmental monitoring, and translational medicine. Frontiers in Optics 2023 + Laser Science (FiO/LS) Conference.
• Su, T. J. (2023). Ultra-sensitive, selective, and label-free optical sensing for fundamental science, environmental monitoring, and translational medicine. Gordon Research Conference, Lasers in Micro, Nano and Bio Systems.
• Su, T. J. (2023). Ultra-sensitive, selective, and label-free optical sensing for fundamental science, environmental monitoring, and translational medicine. ICANX youth talk.
• Su, T. J. (2023). Welcome to IONS. IONS 2023 (International OSA Network of Students).
• Su, T. J. (2021). Detection and prevention of cancer. University of Arizona Cancer Center Convergence 2021University of Arizona Cancer Center.
• Su, T. J. (2021). Early cancer detection using microtoroid optical resonators. University of Arizona Cancer Center Clinical and Translational Oncology Program meetingUniversity of Arizona Cancer Center.
• Su, T. J. (2021). Flow visualization of analyte transport to microtoroid optical resonators. SPIE Photonics West 2021.
• Su, T. J. (2021). Frequency-locked optical microresonator noise analysis. SPIE Photonics West 2021.
• Su, T. J. (2021). Label-free ultra-sensitive molecular detection for chemistry, biology and medicine. CLEO.
• Su, T. J. (2021). Label-free, single-molecule detection using ultra-sensitive optical sensors. Invited Seminar Polytechnic University of Bari, Department of Electrical and Information EngineeringPolytechnic University of Bari, Department of Electrical and Information Engineering.
• Su, T. J. (2021). Medical sensors for disease diagnostics. University of Arizona, College of Engineering Fall 2021 Faculty Lectures Series.
• Su, T. J. (2021). Microtoroid optical sensing technology for biomedical and environmental applications. University of Arizona, Department of Chemistry, Analytical Chemistry Spring Seminar Series.
• Su, T. J. (2021). Microtoroid optical sensing technology for biomedical applications. IEEE Photonics Conference.
• Su, T. J. (2021). Microtoroid optical sensing technology for biomedical applications. IEEE Sensors Conference.
• Su, T. J. (2021). Part per trillion trace gas detection using frequency locked whispering gallery mode microtoroid. SPIE Photonics West.
• Su, T. J. (2021). Prevention and detection of breast cancer. University of Arizona, Ginny L. Clements Breast Cancer Research Institute, New Hope for Breast Cancer Research.
• Su, T. J. (2021). Ultra-sensitive and selective detection of DNA & protein biomarkers using frequency-locked microtoroid optical resonators. University of Arizona Health Sciences Tech Talk Tuesdays.
• Gin, A., Nguyen, P., & Su, T. J. (2020, February). Label-free ultrasensitive detection of Amyloid- using microtoroid resonators with lipid surface functionalization. SPIE Photonics West.
• McLeod, E., Su, J., Nguyen, P., & Melzer, J. E. (2020, September). Assembly of Nanophotonic Structures Using Optical Tweezers. Frontiers in Optics. Virtual: Optical Society of America.
• Su, T. J. (2020, February). Ultra-Sensitive and Selective Detection of Protein Biomarkers Using Frequency-Locked Microtoroid Optical Resonators". SPIE Photonics West.
• Chen, L., Li, C., Teimourpour, M., Liu, Y., Su, T. J., & Mcleod, E. (2019, February). Photonic nanostructures for robust far-field coupling to high-Q whispering-gallery mode optical resonators. SPIE Photonics West.
• Li, C., Chen, L., Mcleod, E., & Su, T. J. (2019, February). Rationally designed nanoantennas coupled to microtoroids for enhanced biochemical sensing. SPIE Photonics West.
• Li, C., Teimourpour, M., Nguyen, P., Chen, L., Mcleod, E., & Su, T. J. (2019, February). Dark mode plasmonic cavity biosensor. SPIE Photonics West.
• Mcleod, E., Su, T. J., Liu, Y., Li, C., & Chen, L. (2019, July). Simulating Travelling Waves in Large 3D Whispering Gallery Mode Resonators Decorated with Plasmonic Nanoparticles. Advanced Photonics Congress. San Francisco: OSA.
• Su, T. J. (2019, April). Label-free ultra-sensitive molecular detection for bioscience and translational medicine. OSA Biophotonics CongressOptical Society of America.
• Su, T. J. (2019, February). Label-Free Ultra-Sensitive Biomolecular Detection for Basic Science and Translational Medicine. Arizona Photonics DayUniversity of Arizona.
• Su, T. J. (2019, February). Label-free ultra-sensitive biomolecular detection for basic science and translational medicine. Arizona Photonics Days. Tucson, Arizona.
• Su, T. J. (2019, July). Label-Free, Single Molecule Detection Using Frequency- Locked Microtoroid Optical Resonators. Faculty seminarHarbin Institute of Technology.
• Su, T. J. (2019, July). Label-Free, Single Molecule Detection Using Frequency-Locked Microtoroid Optical Resonators. Light Conference 2019Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Sciences (CAS), and Light: Science & Applications' Editorial Office..
• Su, T. J. (2019, July). Ultra- Sensitive Detection of Circulating Tumor DNA using Microtoroid Optical Resonators. Prostate Cancer Working Group Annual MeetingUniversity of Arizona Cancer Center Prostate Cancer Working Group.
• Su, T. J. (2019, November). Label-Free Single Molecule Detection Using Microtoroid Optical Resonators. Arizona Research Institute for Biomedical Imaging Spring Workshop.
• Su, T. J., Mcleod, E., Chen, L., & Li, C. (2019, April). Plasmonic Dark Modes for Enhanced Microcavity Biosensing. Biophotonics Congress: Optics in the Life Sciences. Tucson: OSA.
• Su, T. J., Ozgur, E., Roberts, K., Ozgur, E., Gin, A., Bankhead, J., & Wang, Z. (2019, February). Frequency-locked optical microresonator biosensors for ultrasensitive doping detection in urine. SPIE Photonics West.
• Ozgur, E., Roberts, K., Ozgur, E., Gin, A., Bankhead, J., & Su, T. J. (2018, Fall). Rapid, Label-free, and Ultra-Sensitive Detection of Urine hCG Using Frequency-locked On-chip Optical Microcavities. BMES 2018. Atlanta, Georgia: Biomedical Engineering Society.
• Su, T. J. (2018, Summer 2018). Label-Free Ultra-Sensitive Biomolecular Detection for Basic Science and Translational Medicine. Light 2018. Changchun, China: Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Sciences (CAS), and Light: Science & Applications' Editorial Office.
• Su, T. J., Mcleod, E., Teimourpour, M., & Li, C. (2018, April). Enhanced Whispering Gallery Mode Sensors. SPIE Defense and Commercial Sensing.
• Su, T. J. (2017, August). Label-Free Single Biological Molecule Detection Using Microtoroid Optical Resonators. Optical Society of America's 2017 Siegman International School on Lasers. Leon, Mexico: Optical Society of America's 2017 Siegman International School on Lasers.
• Su, T. J. (2017, August). Single Molecule Detection with Microtoroid Resonators. University of Arizona, College of Optical Sciences, Fall ColloquiumUniversity of Arizona, College of Optical Sciences.
• Su, T. J. (2017, December). Label-Free Ultra-Sensitive Biomolecular Detection for Basic Science and Translational Medicine. Shanghai Jiao Tong University, Biomedical Engineering, Department Seminar. Shanghai Jiao Tong University, China: Shanghai Jiao Tong University, China.
• Su, T. J. (2017, December). Label-Free Ultra-Sensitive Biomolecular Detection for Basic Science and Translational Medicine. Southeast University, Biomedical Engineering Department Seminar. Southeast University, China: Southeast University, China.
• Su, T. J. (2017, June). Label-Free Ultra-Sensitive Biomolecular Detection for Basic Science and Translational Medicine. Invited talk at Beijing Institute of Heart, Lung, and Blood Vessel Diseases, Beijing Anzhen Hospital. Beijing Institute of Heart, Lung, and Blood Vessel Diseases, Beijing Anzhen Hospital: Beijing Institute of Heart, Lung, and Blood Vessel Diseases, Beijing Anzhen Hospital.
• Su, T. J. (2017, June). Single Molecule Detection with Microtoroid Resonators. Institute of Information Photonics and Optical Communications (IPOC), Beijing University of Posts and Telecommunications (BUPT) Faculty Seminar. Institute of Information Photonics and Optical Communications (IPOC), Beijing University of Posts and Telecommunications (BUPT): Institute of Information Photonics and Optical Communications (IPOC), Beijing University of Posts and Telecommunications (BUPT).
• Su, T. J. (2017, June). Single Molecule Detection with Microtoroid Resonators. Invited talk, National Center for Nanoscience and Technology, China. National Center for Nanoscience and Technology, China: National Center for Nanoscience and Technology, China.
• Su, T. J. (2017, June). Single Molecule Detection with Microtoroid Resonators. Peking University, Department of Physics Seminar. Peking University, Department of Physics: Peking University, Department of Physics Seminar.
• Su, T. J. (2017, October). Single Molecule Detection with Microtoroid Resonators. University of Arizona, Biomedical Engineering Seminar. University of Arizona: University of Arizona.
• Su, T. J. (2016, February). Single exosome detection in serum using microtoroid optical resonators. FRONTIERS IN BIOLOGICAL DETECTION: FROM NANOSENSORS TO SYSTEMS VIII.
• Su, T. J. (2016, January). Biosensing with Optical Resonators. University of Arizona, College of Optical Sciences, Optics and Photonics Winter School and Workshop. University of Arizona, College of Optical Sciences, Optics and Photonics Winter School and Workshop: University of Arizona, College of Optical Sciences, Optics and Photonics Winter School and Workshop.
• Su, T. J. (2016, October). Label-Free Single Biological Molecule Detection Using Microtoroid Optical Resonators. University of Arizona, College of Optical Sciences 2016 Fall Industrial Affiliates Workshop. University of Arizona, College of Optical Sciences: University of Arizona, College of Optical Sciences 2016 Fall Industrial Affiliates Workshop.
• Su, T. J. (2016, September). Biosensing with Optical Resonators. University of Arizona's Cancer Center Imaging Program Meeting. University of Arizona's Cancer Center: University of Arizona's Cancer Center.
• Su, T. J. (2015, April). Label-Free Single Biological Molecule Detection Using Microtoroid Optical Resonators. University of Arizona, College of Optical Sciences. University of Arizona, College of Optical Sciences: University of Arizona, College of Optical Sciences.
• Su, T. J. (2015, April). Label-Free Single Exosome Detection Using Frequency-Locked Microtoroid Optical Resonators. 2015 Congress of the International Society for Extracellular Vesicles (ISEV2015). 2015 Congress of the International Society for Extracellular Vesicles (ISEV2015), Washington, D.C.: 2015 Congress of the International Society for Extracellular Vesicles (ISEV2015).
• Su, T. J. (2015, February). Label-Free Single Molecule Detection Using Microtoroid Optical Resonators. SPIE BIOS. SPIE BIOS, San Francisco, CA: SPIE BIOS.
• Su, T. J. (2015, July). Label-Free Single Biological Molecule Detection Using Microtoroid Optical Resonators. University of Western Australia, Bioengineering Seminar. University of Western Australia: University of Western Australia.
• Su, T. J. (2015, June). Label-Free Single Exosome Detection Using Frequency-Locked Microtoroid Optical Resonators. GTC Molecular Diagnostics Summit, Cancer Markers & Liquid Biopsies Conference. GTC Molecular Diagnostics Summit, Cancer Markers & Liquid Biopsies Conference, San Diego, CA,: GTC Molecular Diagnostics Summit, Cancer Markers & Liquid Biopsies Conference.
• Su, T. J. (2014, December). Label-Free Single Biological Molecule Detection Using Microtoroid Optical Resonators. Presentation. MIT, Department of Chemistry, Laser Biomedical Research Center: MIT, Department of Chemistry, Laser Biomedical Research Center.
• Su, T. J. (2014, May). Label-Free Single Biological Molecule Detection Using Microtoroid Optical Resonators. Caltech Division of Biology and Biology Engineering Structural Biology Joint Meeting. Caltech Division of Biology and Biology Engineering Structural Biology Joint Meeting: Caltech Division of Biology and Biology Engineering Structural Biology Joint Meeting.
• Su, T. J., & Arnold, S. (2014, November). Label-Free Detection of Single Biological Molecules Using Microtoroid Optical Resonators. Materials Research Society. Materials Research Society, Boston, MA: Materials Research Society.
• Su, T. J., Goldberg, A., Stoltz, B., Arnold, S., & Fraser, S. (2014, April). Label-Free Detection of Single Nanoscale Particles Using Microtoroid Optical Resonators. 560. WE Heraeus Seminar: Taking Detection to the Limit: Biosensing with Optical Microcavities. Bad Honnef, Germany: 560. WE Heraeus Seminar: Taking Detection to the Limit: Biosensing with Optical Microcavities.
• Su, T. J., Jiang, X., Whitesides, G., & So, P. (2005, March). Lithographic Regulation of Cellular Migration and Mechanics. New England Complex Fluids Workshop. New England Complex Fluids Workshop, Cambridge, MA: New England Complex Fluids Workshop.
• Su, T. J., & Su, J. (2001, November). Theory of Vortex Fusion. Proceedings of the 54th American Physical Society Division of Fluid Dynamics MeetingAmerican Physical Society Division of Fluid Dynamics Meeting.
• Su, T. J. (2000, July). The Physics of Granular Materials. MIT Dept. of Mathematics Physical Math Brown Bag Seminar. MIT Dept. of Mathematics Physical Math Brown Bag Seminar: MIT Dept. of Mathematics Physical Math Brown Bag Seminar.
• Su, T. J. (1999, August). Experimental Investigation of Size Segregation in Granular Media. MIT Dept. of Mathematics Physical Math Brown Bag Seminar. MIT Dept. of Mathematics Physical Math Brown Bag Seminar: MIT Dept. of Mathematics Physical Math Brown Bag Seminar.
• Su, T. J. (1999, July). Size Segregation of Beans in a Rotating Horizontal Cylinder. MIT Dept. of Mathematics Physical Math Brown Bag Seminar. MIT Dept. of Mathematics Physical Math Brown Bag Seminar: MIT Dept. of Mathematics Physical Math Brown Bag Seminar.

Poster Presentations

• Luu, G., Ge, C., Tang, Y., Godwin, A., Su, T. J., & Sanchez, L. (2023). Identification of Putative Early-Stage Ovarian Cancer Biomarkers Using Bottom-Up Proteomics from Patient Derived Tampons. ASMS Conference on Mass Spectrometry and Allied Topics.
• Su, T. J. (2023). Ultra-sensitive, selective, and label-free optical sensing for fundamental science, environmental monitoring, and translational medicine. Gordon Research Conference on Lasers in Micro, Nano and Bio Systems.
• Su, T. J., & Sanchez, L. (2023). Identifying and Detecting Diseases Prior to Physical Presentation of Symptoms -- Recent Progress. 7th Annual Arizona Biomedical Research Center-Flinn Research Conference.
• Su, T. J. (2021). Identifying and Detecting Diseases Prior to Physical Presentation of Symptoms. 5th Annual Arizona Biomedical Research Center-Flinn Research Conference.
• Su, T. J., Stoltz, B., Melzer, J. E., Li, C., Chen, L., & Mcleod, E. (2019, November). Nanostructuring microtoroid optical chemosensors for mechanically robust and stable sensing. Chemical and Biological Defense Science & Technology Conference. Cincinnati: Defense Threat Reduction Agency (DTRA).
• Roberts, K., Ozgur, E., & Su, T. J. (2017, October). Microtoroid Optical Resonators as a Novel Platform for Selective Drug Detection. Biomedical Engineering Society Annual Fall Meeting. Phoenix, Arizona, USA: Biomedical Engineering Socity.
• Su, T. J. (2014, September). Label-Free Single Exosome Detection Using Frequency Locked Microtoroid Optical Resonators. Exosomes & Single Cell Analysis Summit. Exosomes & Single Cell Analysis Summit, San Diego, CA: Exosomes & Single Cell Analysis Summit.
• Su, T. J., Goldberg, A., Raubitschek, A., Stoltz, B., & Fraser, S. E. (2013, February). Frequency locked microtoroid optical resonators as a non-invasive tumor biopsy alternative. Proceedings of the 57th Biophysical Society Annual Meeting. Proceedings of the 57th Biophysical Society Annual Meeting in Philadephia, PA: Proceedings of the 57th Biophysical Society Annual Meeting.
• Su, T. J., Brau, R. R., Jiang, X., Whitesides, G. M., Lang, M. J., & So, P. (2006, February). Combining Magnetic and Optical Trapping to Quantify Position Dependent Variations in Cellular Rheology. Proceedings of the 50th Biophysical Society Annual Meeting. Proceedings of the 50th Biophysical Society Annual Meeting in Salt Lake City, UT: Proceedings of the 50th Biophysical Society Annual Meeting.
• Su, T. J., Brau, R. R., Jiang, X., Whitesides, G. M., Lang, M. J., & So, P. (2006, July). Combining Magnetic and Optical Trapping to Quantify Position Dependent Variations in Cellular Rheology. Gordon Conference, Lasers in Biology and Medicine. Gordon Conference, Lasers in Biology and Medicine, Meriden, NH: Gordon Conference, Lasers in Biology and Medicine.
• Su, T. J., & So, P. (2005, September). Lithographic Regulation of Cellular Mechanical Properties. Proceedings of the 2005 BMES Annual Fall Meeting. Proceedings of the 2005 BMES Annual Fall Meeting, Baltimore MD: Proceedings of the 2005 BMES Annual Fall Meeting.
• Su, T. J., Jiang, X., Whitesides, G. M., & So, P. (2005, February). Lithographic Regulation of Cellular Migration and Mechanics. Proceedings of the 49th Biophysical Society Annual Meeting. Proceedings of the 49th Biophysical Society Annual Meeting in Long Beach, CA: Proceedings of the 49th Biophysical Society Annual Meeting.
• Su, T. J., & So, P. (2004, February). Lithographic Regulation of Cellular Mechanical Properties. Proceedings of the 48th Biophysical Society Annual Meeting. Proceedings of the 48th Biophysical Society Annual Meeting, Baltimore, MD: Proceedings of the 48th Biophysical Society Annual Meeting.
• Su, T. J., & So, P. (2004, July). Lithographic Regulation of Cellular Mechanical Properties. Gordon Conference, Lasers in Biology and Medicine. Gordon Conference, Lasers in Biology and Medicine, Meriden, NH: Gordon Conference, Lasers in Biology and Medicine.
• Su, T. J., & So, P. (2004, October). Lithographic Regulation of Cellular Mechanical Properties. Proceedings of the 2004 BMES Annual Fall Meeting. Proceedings of the 2004 BMES Annual Fall Meeting in Philadelphia, PA,: Proceedings of the 2004 BMES Annual Fall Meeting.
• Su, T. J., & So, P. (2003, October). Structure and Strength of the Actin Filaments of Micropatterned Cells. Proceedings of the First US National Symposium on Frontiers in Biomechanics Meeting. Proceedings of the First US National Symposium on Frontiers in Biomechanics Meeting, Nashville, TN: Proceedings of the First US National Symposium on Frontiers in Biomechanics Meeting.
• Su, T. J., & So, P. (2003, October). The Actin Structure and Mechanical Behavior of Cells Binding to Extra-Cellular Matrix Adhered to Micropatterned Substrates. Proceedings of the 2003 BMES Annual Fall Meeting. Proceedings of the 2003 BMES Annual Fall Meeting: Proceedings of the 2003 BMES Annual Fall Meeting.
• Su, T. J., Zwieniecki, M., Holbrook, N. M., & So, P. (2003, March). Phloem Transport in Arabidopsis Thalania Seedlings as a Function of Osmotic Stress. Proceedings of the 47th Biophysical Society Annual MeetingBiophysical Society.