About

M. Selim Ünlü is a professor affiliated with the Department of Electrical and Computer Engineering at Boston University. His research focuses on near-field optical microscopy and spectroscopy of semiconductor materials and devices, as well as the design, processing, and characterization of semiconductor optoelectronic devices. He also investigates nanoscale imaging of biological samples and biosensors, along with areas such as nano-optics, biophotonics, high-speed and Resonant Cavity Enhanced (RCE) photodetectors, and thermal imaging. Ünlü has made significant contributions to the development of optical sensing technologies and photonic devices, with a notable emphasis on high-resolution subsurface microscopy and the optical characterization of semiconductor materials. His work has been recognized through numerous awards, including the IEEE Lasers and Electro-optics Society (LEOS) Distinguished Lecturer, the ONR Young Investigator Award, and the NSF CAREER Award. He holds a B.S. in electrical engineering from Middle East Technical University, an M.S. and Ph.D. in electrical engineering from the University of Illinois at Urbana-Champaign. Ünlü is also known for his involvement in developing technology to combat Ebola, as highlighted in recent news.

Research topics

• Computer Science
• Artificial Intelligence
• Materials science
• Optics
• Chemistry
• Nanotechnology
• Physics
• Geology
• Virology
• Chromatography
• Remote sensing
• Biophysics

Selected publications

• Impact of uniform illumination in widefield microscopy and mesoscopy: An efficient flat-field imaging solution

  2025-01-15

  preprint1st authorCorresponding

  Illumination uniformity is critical for widefield optical microscopy, especially for high-throughput and accurate quantitative imaging of biological specimens. While traditional Köhler illumination improves uniformity, it often fails to deliver homogeneous intensity across large fields of view. Existing optical and computational correction techniques remain inadequate for a broad range of quantitative imaging applications. Here, we implement a novel illumination device that we call the effective uniform color-light integration device (EUCLID), quantifying improvements in two widefield imaging modalities that require uniform illumination. For both imaging modalities, we demonstrate significantly improved precision of quantitative measurements compared to traditional Köhler illumination. The EUCLID device, which can also provide uniform spectral mixing, can be readily adapted to many other widefield imaging modalities to enhance imaging accuracy and reliability, with low cost and ease of implementation.

  PublisherDOI

• Impact of uniform illumination in widefield microscopy and mesoscopy: An efficient flat-field imaging solution

  2025-01-15

  preprintOpen access1st authorCorresponding

  Illumination uniformity is critical for widefield optical microscopy, especially for high-throughput and accurate quantitative imaging of biological specimens. While traditional Köhler illumination improves uniformity, it often fails to deliver homogeneous intensity across large fields of view. Existing optical and computational correction techniques remain inadequate for a broad range of quantitative imaging applications. Here, we implement a novel illumination device that we call the effective uniform color-light integration device (EUCLID), quantifying improvements in two widefield imaging modalities that require uniform illumination. For both imaging modalities, we demonstrate significantly improved precision of quantitative measurements compared to traditional Köhler illumination. The EUCLID device, which can also provide uniform spectral mixing, can be readily adapted to many other widefield imaging modalities to enhance imaging accuracy and reliability, with low cost and ease of implementation.

  PublisherOA PDFDOI

• Nanomaterial-Based Sensing Systems to Detect Neuropharmaceutical Compounds and Neurotransmitters

  Sensors · 2025-05-22 · 5 citations

  reviewOpen accessSenior author

  This review explores the application of nanomaterial-based sensing systems for precisely detecting neuropharmaceutical compounds and neurotransmitters, delving into the connections between nanotechnology and neuropharmacology. Nanotechnology appears as a promising solution for many significant challenges posed by the complexities of the brain's biochemical nature. Using nanoscale materials, scientists have created novel sensors with high selectivity, sensitivity, and adaptability. Developing neuropharmaceutical compounds and monitoring their side effects on our neurological system raised the need for these nanomaterial-based sensors. In this review, we demonstrate the effectiveness of these technologies in real-time neuroactive compound detection and monitoring by illuminating the underlying principles through an examination of significant studies and recent developments. This review also highlights collaborative efforts at the intersection of nanotechnology and neuropharmacology and their direct and indirect effects on the understanding and controlling several neurological disorders. This review covers both sensors under research and those already applied in vivo or clinical monitoring of drug side effects.

  PublisherOA PDFDOI

• Impact of uniform illumination in widefield microscopy and mesoscopy

  Scientific Reports · 2025-07-14 · 5 citations

  articleOpen accessSenior author

  Illumination uniformity is critical for widefield optical microscopy, especially for high-throughput and accurate quantitative imaging of biological specimens. While traditional Köhler illumination improves uniformity, it often fails to deliver homogeneous intensity across large fields of view. Existing optical and computational correction techniques remain inadequate for a broad range of quantitative imaging applications. Here, we implement a novel illumination device that we call the "effective uniform color-light integration device" (EUCLID), quantifying improvements in two widefield imaging modalities that require uniform illumination. For both imaging modalities, we demonstrate significantly improved precision of quantitative measurements compared to traditional Köhler illumination. The EUCLID device, which can also provide uniform spectral mixing, can be readily adapted to many other widefield imaging modalities to enhance imaging accuracy and reliability, with low cost and ease of implementation.

  PublisherOA PDFDOI

• Interferometric reflectance imaging sensor for biothreat detection (IRIS-BD)

  2025-05-28

  article
  PublisherDOI

• Web Based Educational Experiments

  2024-01-31 · 10 citations

  articleOpen accessSenior author

  Abstract NOTE: The first page of text has been automatically extracted and included below in lieu of an abstract Session 3232 Web-Based Educational Experiments Justin C. Pniower, Michael Ruane, Bennett B. Goldberg, M. Selim Ünlü Boston University Abstract Web-based educational experiments allow remote users to conduct laboratory explorations using physical experimental apparatuses in real time over the World Wide Web. Web-based experimentation is evolving rapidly and offers students convenient and repeated access to limited laboratory resources. The immediacy and accessibility of web-based experiments can also assist new student outreach and faculty teaching effectiveness. Many web-based experiments can be realized with commercial off the shelf hardware and software, linked through a dedicated laboratory PC with a suitable network connection. Users can control the experimental apparatus, initiate data collection, transfer data across the web, and observe the progress of the experiment using a live video link. We report specifically on two web-based experiments operating since spring 1998: a Michelson interferometer that allows mirror movement and fringe counting, and a laser diode characterization experiment that allows current control and power measurements to observe P-I curves and the onset of laser action. Descriptions include benchtop optical and electronic experimental hardware, LabVIEW software tools for hardware interfacing, HTML web interfacing tools, and the video link setup. We also describe a typical user's experience across the web, discuss plans for extended web-based experiments and give suggestions for creating and maintaining a successful web-based experiment at another institution. Introduction The World Wide Web (WWW) is a growing vehicle for distance education, but most efforts have treated the web as a communications channel, not as a means for tele-presence. Boston University has been developing several photonics experiments that demonstrate basic principles of science and engineering through active experimental control over the WWW. Visitors to our web-site have real-time control over scientific equipment using their basic web-browsers, and receive observed data across the web. We have found that web-based experiments offer advantages to faculty, students, and general visitors to our web site. Similar efforts are being developed widely1,2,3,4. Web-based experiments are an excellent complement to traditional lab resources. They can be superior to simulations, which cannot replicate all of the parameters and factors that accompany a real life educational experiment. They also offer an attraction to users who enjoy their live, real-time aspects. Web-based experiments also give educators increased access to engineering resources, especially during experiments that require expensive or fragile equipment or that

  PublisherOA PDFDOI

• A Label-free Optical Biosensor-Based Point-of-Care Test for the Rapid Detection of Monkeypox Virus

  medRxiv · 2024-07-05 · 3 citations

  preprintOpen access

  Diagnostic approaches that combine the high sensitivity and specificity of laboratory-based digital detection with the ease of use and affordability of point-of-care (POC) technologies could revolutionize disease diagnostics. This is especially true in infectious disease diagnostics, where rapid and accurate pathogen detection is critical to curbing the spread of disease. We have pioneered an innovative label-free digital detection platform that utilizes Interferometric Reflectance Imaging Sensor (IRIS) technology. IRIS leverages light interference from an optically transparent thin film, eliminating the need for complex optical resonances to enhance the signal by harnessing light interference and the power of signal averaging in shot-noise-limited operation to achieve virtually unlimited sensitivity. In our latest work, we have further improved our previous 'Single-Particle' IRIS (SP-IRIS) technology by allowing the construction of the optical signature of target nanoparticles (whole virus) from a single image. This new platform, 'Pixel-Diversity' IRIS (PD-IRIS), eliminated the need for z-scan acquisition, required in SP-IRIS, a time-consuming and expensive process, and made our technology more applicable to POC settings. Using PD-IRIS, we quantitatively detected the Monkeypox virus (MPXV), the etiological agent for Monkeypox (Mpox) infection. MPXV was captured by anti-A29 monoclonal antibody (mAb 69-126-3) on Protein G spots on the sensor chips and were detected at a limit-of-detection (LOD) - of 200 PFU/ml (~3.3 attomolar). PD-IRIS was superior to the laboratory-based ELISA (LOD - 1800 PFU/mL) used as a comparator. The specificity of PD-IRIS in MPXV detection was demonstrated using Herpes simplex virus, type 1 (HSV-1), and Cowpox virus (CPXV). This work establishes the effectiveness of PD-IRIS and opens possibilities for its advancement in clinical diagnostics of Mpox at POC. Moreover, PD-IRIS is a modular technology that can be adapted for the multiplex detection of pathogens for which high-affinity ligands are available that can bind their surface antigens to capture them on the sensor surface.

  PublisherOA PDFDOI

• Sequential separation and profiling of extracellular vesicles using antibody-aptamer conjugates

  Sensors and Actuators B Chemical · 2024-11-14 · 4 citations

  articleOpen access

  Extracellular vesicles (EVs) are membrane-bound vesicles secreted by cells, exhibiting diverse compositions reflective of their cellular origin. With significant potential as biomarkers for liquid biopsies, EV research has led to various isolation techniques. However, a consensus on the optimal strategy remains elusive. Immunoprecipitation, selectively capturing EVs based on surface markers, is promising but hindered by cost, low yields, and potential damage during release. In this study, we propose an innovative Antibody-Aptamer Conjugate (AAC): a three-component separation reagent for the separation of EVs. Combining an EV-specific antibody, a streptavidin-binding aptamer, and a unique barcode DNA sequence, this conjugate serves dual roles, facilitating both EV separation and subsequent multiplexed analysis. We detail the development and validation of the AAC, demonstrating its efficacy in isolating intact EVs from complex samples. The unique barcode DNA sequence enables high-throughput analysis on a DNA microarray chip, addressing limitations of existing methodologies. This approach offers a valid and cost-effective alternative for selective EV isolation and analysis, with implications for diagnostic and therapeutic advancements in liquid biopsy applications. • Innovative EV separation and analysis using a three-component reagent. • Components include antibody, streptavidin-binding aptamer, and barcode DNA sequence. • Aim: to separate EV subpopulations and enable multiplex analysis on a DNA microarray chip. • Advantages: overcomes limitations of traditional immunoprecipitation, preserves EV integrity. • Potential impact: enhanced diagnostic accuracy in liquid biopsies.

  PublisherDOI

• Characterization of Receptor Binding Affinity for Vascular Endothelial Growth Factor with Interferometric Imaging Sensor

  Biosensors · 2024-06-24 · 3 citations

  articleOpen accessSenior author

  Wet Age-related macular degeneration (AMD) is the leading cause of vision loss in industrialized nations, often resulting in blindness. Biologics, therapeutic agents derived from biological sources, have been effective in AMD, albeit at a high cost. Due to the high cost of AMD treatment, it is critical to determine the binding affinity of biologics to ensure their efficacy and make quantitative comparisons between different drugs. This study evaluates the in vitro VEGF binding affinity of two drugs used for treating wet AMD, monoclonal antibody-based bevacizumab and fusion protein-based aflibercept, performing quantitative binding measurements on an Interferometric Reflectance Imaging Sensor (IRIS) system. Both biologics can inhibit Vascular Endothelial Growth Factor (VEGF). For comparison, the therapeutic molecules were immobilized on to the same support in a microarray format, and their real-time binding interactions with recombinant human VEGF (rhVEGF) were measured using an IRIS. The results indicated that aflibercept exhibited a higher binding affinity to VEGF than bevacizumab, consistent with previous studies using ELISA and SPR. The IRIS system's innovative and cost-effective features, such as silicon-based semiconductor chips for enhanced signal detection and multiplexed analysis capability, offer new prospects in sensor technologies. These attributes make IRISs a promising tool for future applications in the development of therapeutic agents, specifically biologics.

  PublisherOA PDFDOI

• A label-free optical biosensor-based point-of-care test for the rapid detection of Monkeypox virus

  Biosensors and Bioelectronics · 2024-11-14 · 26 citations

  articleOpen access

  Diagnostic approaches that combine the high sensitivity and specificity of laboratory-based digital detection with the ease of use and affordability of point-of-care (POC) technologies could revolutionize disease diagnostics. This is especially true in infectious disease diagnostics, where rapid and accurate pathogen detection is critical to curbing the spread of disease. We have pioneered an innovative label-free digital detection platform that utilizes Interferometric Reflectance Imaging Sensor (IRIS) technology. IRIS leverages light interference from an optically transparent thin film, eliminating the need for complex optical resonances to enhance the signal by harnessing light interference and the power of signal averaging in shot-noise-limited operation In our latest work, we have further improved our previous 'Single-Particle' IRIS (SP-IRIS) technology by allowing the construction of the optical signature of target nanoparticles (whole virus) from a single image. This new platform, 'Pixel-Diversity' IRIS (PD-IRIS), eliminated the need for z-scan acquisition, required in SP-IRIS, a time-consuming and expensive process, and made our technology more applicable to POC settings. Using PD-IRIS, we quantitatively detected the Monkeypox virus (MPXV), the etiological agent for Monkeypox (Mpox) infection. MPXV was captured by anti-A29 monoclonal antibody (mAb 69-126-3) on Protein G spots on the sensor chips and were detected at a limit-of-detection (LOD) - of 200 PFU/mL (∼3.3 aM). PD-IRIS was superior to the laboratory-based ELISA (LOD - 1800 PFU/mL) used as a comparator. The specificity of PD-IRIS in MPXV detection was demonstrated using Herpes simplex virus, type 1 (HSV-1), and Cowpox virus (CPXV). This work establishes the effectiveness of PD-IRIS and opens possibilities for its advancement in clinical diagnostics of Mpox at POC. Moreover, PD-IRIS is a modular technology that can be adapted for the multiplex detection of pathogens for which high-affinity ligands are available that can bind their surface antigens to capture them on the sensor surface.

  PublisherDOI

Frequent coauthors

• Bennett B. Goldberg

  Boston University

  199 shared

• Anna K. Swan

  University of Washington

  92 shared

• Marcella Chiari

  National Research Council

  42 shared

• George G. Daaboul

  Precision BioSciences (United States)

  38 shared

• Ekmel Özbay

  35 shared

• John H. Connor

  Boston University

  34 shared

• Neşe Lortlar Ünlü

  32 shared

• Abdulkadir Yurt

  31 shared

Education

• Ph.D., Physics

  Massachusetts Institute of Technology

  1992

• M.S., Physics

  Massachusetts Institute of Technology

  1989

• B.S., Physics

  Bosphorus University

  1986

Awards & honors

• IEEE Lasers and Electro-optics Society (LEOS) Distinguished…
• ONR Young Investigator Award (1996)
• NSF CAREER Award (1996)
• Senior Member, IEEE
• Associate Editor, IEEE Journal of Quantum Electronics