Bio Photonics Research

Researchers at North Carolina State University (NCSU) have successfully demonstrated a spectrometer that is orders of magnitude smaller than current technologies and can accurately measure wavelengths of light from ultraviolet to the near-infrared (NIR). The technology makes it possible to create hand-held spectroscopy devices and holds promise for the development of devices that incorporate an array of the new sensors to serve as next-generation imaging spectrometers, the researchers said. Spectrometers are used in applications ranging from manufacturing to biomedical diagnostics to discern the chemical and physical properties of various materials based on how light changes as it interacts with those materials. Despite their widespread use, even the smallest spectrometers on the market are fairly cumbersome. “We’ve created a spectrometer that operates quickly, at low voltage, and that is sensitive to a wide spectrum of light,” said Brendan O’Connor, corresponding author of a pape...

Photoimmunotherapy targets cancer cells with microscopic, nano -engineered cancer drugs that are light-activated at the lesion site. Although the technology is increasingly used to treat metastatic cancer, tools to improve the effectiveness of photoimmunotherapy in gynecologic oncology have been lacking. Responses to treatment vary from person to person, and no method has existed to readily monitor whether the drugs are delivered effectively or have the desired therapeutic effect. Researchers from the University of Maryland (UMD), in collaboration with medical laser manufacturer Modulight, demonstrated that the efficacy, safety, and consistency of photoimmunotherapy can be improved by integrating targeted, light-based techniques for drug delivery with laser-assisted endoscopy and fluorescence -guided treatment planning. The researchers designed a drug delivery system using targeted, photo-activable, multi-agent liposomes (TPMAL). TPMAL consists of chemotherapy drugs that are labeled ...

Biomolecular condensates — membraneless, microscopic structures that concentrate proteins and other molecules in cells — are crucial to the organization of cellular biochemistry. Insight into the development and behavior of condensates could lead to better treatments for infectious diseases, cancer, and neurological disorders. Researchers at New York University (NYU) aimed to measure condensate composition and dynamics without relying on conventional techniques, like fluorescence labeling or surface attachment, which can damage fragile condensate samples. Until now, scientists have needed to distort condensate samples to study them. “It’s been the elephant in the room for scientists,” professor Saumya Saurabh said. “Our research provides a precise and noninvasive way to study biomolecular condensates.” To overcome the limitations of conventional techniques, the team used label-free holographic microscopy to investigate the behavior of a condensate-forming protein in vitro. The resear...

  Oral cancer is a growing public health concern, particularly in South Asia, where it affects tens of thousands each year. In India alone, oral cancer accounts for 40% of all cancers, largely driven by the widespread use of tobacco-based products. The situation is worsened by limited access to early screening and treatment, especially in rural and underserved areas. Most cases are diagnosed at advanced stages, when treatment is more difficult and survival rates are lower. To address this problem, a team of researchers has developed a compact, affordable device that can both image suspicious lesions and deliver light-based therapy to treat them. The device uses a smartphone-coupled intraoral probe with specialized LEDs and filters to capture white-light and fluorescence images to pinpoint oral cancers. It also includes laser diodes to activate a light-sensitive compound called protoporphyrin IX (PpIX), which accumulates in cancerous tissue after the application of a precursor dru...

  A smartphone-inspired spectrometer platform, built with low-cost plastic materials instead of glass, could make spectral imaging more accessible across the scientific, industrial, and consumer domains. The spectrometer spans the visible to SWIR range and is fabricated using mass-producible, non-lithographic methods. These properties could make it suitable for in-home health care monitoring, food quality testing, agricultural sensing, and many other applications that require affordable, broadband sensing capabilities. The spectrometer design is the result of a collaboration among researchers at the University of Cambridge, Zhejiang University, Zhejiang Sci-Tech University, and Nanyang Technological University, with backgrounds in materials science, optical engineering, and signal processing. Plastic optical components are used in smartphone cameras to achieve high performance in an ultracompact format. Inspired by this approach, the research team took a similar path, using transp...

Lasers based on titanium-sapphire (Ti:sapphire) provide top performance in fields like quantum optics, spectroscopy , and neuroscience. But that performance comes at a steep cost of not just the multi-thousand dollar price tag, but space and power as well. Ti:sapphire lasers take up several cubic feet and require other high-powered lasers to supply them with enough energy to function. Despite their high level of performance and utility in cutting edge applications, their adoption in the industry has been slow. Making a jump from tabletop to the microscale, engineers at Stanford University have built a Ti:sapphire laser on a chip. According to the researchers, the prototype is four orders of magnitude smaller (10,000×) and three orders less expensive (1,000×) than any Ti:sapphire laser ever produced. “Instead of one large and expensive laser, any lab might soon have hundreds of these valuable lasers on a single chip. And you can fuel it all with a green laser pointer,” said Jelena Vuck...

Oral cancer is a growing public health concern, particularly in South Asia, where it affects tens of thousands each year. In India alone, oral cancer accounts for 40% of all cancers, largely driven by the widespread use of tobacco-based products. The situation is worsened by limited access to early screening and treatment, especially in rural and underserved areas. Most cases are diagnosed at advanced stages, when treatment is more difficult and survival rates are lower. To address this problem, a team of researchers has developed a compact, affordable device that can both image suspicious lesions and deliver light-based therapy to treat them. The device uses a smartphone-coupled intraoral probe with specialized LEDs and filters to capture white-light and fluorescence images to pinpoint oral cancers. It also includes laser diodes to activate a light-sensitive compound called protoporphyrin IX (PpIX), which accumulates in cancerous tissue after the application of a precursor drug, 5-a...

Perovskites, a family of organic-inorganic hybrid materials, are efficient at converting light to electricity and relatively easy to make. They absorb certain colors of the visible spectrum effectively and can be layered with other materials, such as silicon, that absorb wavelengths the perovskites cannot capture. But the low photostability of perovskites makes it difficult to improve their performance. Perovskite solar cells can be made from many different combinations of chemical compositions and prepared under various conditions. It is hard to predict how these factors will affect the structure and performance of the perovskite cell. Many complex materials found in semiconductors, displays, and quantum and biomedical applications present the same challenge. To better understand how to improve these materials, scientists need to be able to visualize the material’s dynamics at the subatomic, atomic, and molecular levels. A research team at the University of Colorado-Boulder (CU Boul...

  Multidrug-resistant bacteria are considered a serious threat to infection control. Faced with the increasing difficulty of developing new antibiotics to combat resilient bacterial strains, scientists are turning to photodynamic inactivation (PDI), a light-based approach to breaking antimicrobial resistance. PDI strengthens the effect of antibiotics and induces oxidative stress in microorganisms through the interaction of light with a photosensitizer. The photosensitizer is energized in PDI by absorbing visible light to form reactive oxygen species that trigger bacterial inactivation by oxidizing and destroying microorganisms or weakening their resistance to antibiotics. In recent work, researchers at the University of São Paulo’s Optics and Photonics Research Center showed that PDI can modify bacterial sensitivity to antibiotics and reduce the resistance and persistence of both standard and clinical strains. The researchers, led by professor Vanderlei Salvador Bagnato, inv...

Researchers at the University of St. Andrews and the University of Cologne have developed lasers that they have described as “squishy.” These devices could help solve the biological mysteries behind the development of embryos and cancerous tumors. Fundamental biological processes driven by mechanical forces invisible to the naked eye are currently poorly understood by scientists. The squishy lasers developed by the researchers are able to precisely measure the forces exerted by biological cells. “Embryos and tumors both start with just a few cells,” said professor Malte Gather from the University of St. Andrews. “It is still very challenging to understand how they expand, contract, squeeze, and fold as they develop. Being able to measure biological forces in real-time could be transformative. It could hold the key to understanding the exact mechanics behind how embryos develop, whether successfully or unsuccessfully, and how cancer grows.” These squishy microlasers can be injected dir...

Single-cell RNA sequencing enables scientists to interrogate cells at extraordinary resolution and scale. However, the sequencing process destroys the cell, making it difficult to use the technique to study ongoing changes in gene expression. Raman microscopy measures the vibrational energy levels of proteins and metabolites in a nondestructive manner at subcellular spatial resolution, but it is unable to interpret genetic information. “RNA sequencing gives you extremely detailed information, but it’s destructive,” researcher Koseki Kobayashi-Kirschvink said. “Raman is noninvasive, but it doesn’t tell you anything about RNA.” A new technique developed at MIT combines the advantages of single-cell RNA sequencing and Raman spectroscopy to track a cell’s RNA expression without damaging the cell. Known as Raman2RNA (R2R), this technique could allow scientists to study long-term cellular processes, such as cancer progression and embryonic development, using the same cells repeatedly. To ...

Although structured illumination microscopy (SIM) demonstrates ultrahigh temporal and spatial resolution, the speed and intricacy of polarization modulation affect the speed and quality of its imaging resolution in 3D. A 3DSIM technique, developed by a team led by professor Peng Xi at Peking University, leverages digital display technology to achieve a rapid, reliable, multidimensional SIM imaging tool for investigating diverse biological phenomena. The new microscopy technique blends 3D superresolution and fast temporal resolution with polarization imaging. To do so, it combines the polarization-maintaining and modulation capabilities of a digital micromirror device (DMD) with an electro-optic modulator (EOM). A DMD uses the electromechanical rotation of micromirrors to modulate the light field reflecting off it. Since each micromirror is controlled in the binary form corresponding to “on” and “off” states, a DMD can also be used as a digital reflection grating when loading with a ...

Optical sectioning enables 3D bioimaging, but it requires non-optical techniques, such as sample adhesion and mechanical scanning, to hold and manipulate cells. In situ living cells may lack mechanical attachment or support, and may experience stress from artificial adhesion. A non-contact solution for optical sectioning could broaden the use of 3D imaging to include live cells suspended in high-fluidity environments, such as water or air. Extending optical sectioning to these nonadherent targets is essential for bioimaging cellular structure and dynamics. Researchers at the Xi’an Institute of Optics and Precision Mechanics (XIOPM) of the Chinese Academy of Sciences, working with a team at the Swiss Federal Institute of Technology, Lausanne (EPFL), developed a method to visualize suspended cells in 3D. Their approach couples structured illumination microscopy (SIM) with holographic optical tweezers . The holographic tweezers enable multiple cells to be manipulated simultaneously usi...

Single-emitter fluorescence detection is used in diverse fields, from biophysics to quantum optics, to precisely observe processes at the single-molecule level. When performed under fluidic conditions, diffusion can restrict the observation time and detected photon counts, hampering the investigation of both slow and fast phenomena occurring in the molecule. To enhance the optical signal from emitters in a liquid and allow longer observation times, researchers at the Max Planck Institute for the Science of Light (MPL) and the University of Düsseldorf developed and characterized an optofluidic antenna (OFA). The optical design of the OFA was adopted from a planar dielectric antenna. The OFA expands the time range for studying biomolecular dynamics beyond the limit imposed by the translational diffusion time in a laser focus. It collects the photons emitted by individual fluorescent molecules with approximately 85% efficiency, enabling a time resolution in the microsecond (μs) range an...

Researchers at Ohio State University are pioneering the field of “imageomics.” Founded on advancements in machine learning and computer vision, the researchers are using imageomics to explore fundamental questions about biological processes by combining images of living organisms with computer-enabled analysis. The field was the subject of a presentation by Wei-Lun Chao, an investigator at Ohio State University’s Imageomics Institute and a distinguished assistant professor, during the annual meeting of the American Association for the Advancement of Science (AAAS). The presentation focused on the field’s application for micro- to macro-level problems by turning research questions into computable problems. “Nowadays we have many rapid advances in machine learning and computer vision techniques,” said Chao. “If we use them appropriately, they could really help scientists solve critical but laborious problems.” Imageomics researchers suggest that with the aid of machine and computer vis...

  Insight into the cellular distribution of RNA, which is closely linked to cell functions, could help scientists better understand the relation between cellular processes and disease. Potentially, this could lead to more targeted treatments for neurodegenerative disorders and aging. While many methods have been developed to study RNA distribution within cells, only a few have been applied on a transcriptome-wide scale. To capture the transcriptome of target cell types at the tissue level and RNA content within subcellular compartments, a research team at the UT Southwestern Medical Center, led by professor Haiqi Chen, developed Photoselection of Transcriptome over Nanoscale (PHOTON). PHOTON combines high-resolution imaging with high-throughput sequencing to achieve spatial transcriptome profiling of RNA at subcellular resolution. It identifies RNA molecules at their native locations within cells, showing where different RNA species are distributed spatially in response to cellul...

The development of a compact, self-illuminating plasmonic sensor could make high-performing optical biosensors more accessible for rapid diagnostics and environmental monitoring and in point-of-care settings. The plasmonic biosensor can focus light waves down to a scale small enough to detect proteins and amino acids, without needing a bulky, expensive external light source. By exploiting a quantum phenomenon called inelastic electron tunneling, researchers at the École Polytechnique Fédérale de Lausanne (EPFL), aided by colleagues at ETH Zurich, ICFO, and Yonsei University, created a biosensor that requires only a steady flow of electrons, in the form of an applied electrical voltage, to illuminate and detect molecules. As an electron passes through a multilayer (metal-insulator-metal) film in the sensor structure, it transfers some of its energy to a plasmon, which then emits a photon. The intensity and spectrum of the light changes in response to contact with a biomolecule. “If yo...

An optical imaging system from UCLA goes beyond the traditional diffraction limit to enable imaging at subwavelength resolution. The new imager will make direct imaging of phase objects with subwavelength resolution less challenging for bioimaging, sensing, material characterization, and other applications that frequently use phase imaging. The imager, developed in the lab of UCLA professor Aydogan Ozcan, enables subwavelength imaging of phase and amplitude objects. To enable the imager to recover high-frequency information corresponding to the subwavelength features of an object, the research team uses all-optical diffractive encoding and decoding with a solid-immersion layer. The imager’s thin, high-index, solid-immersion layer transmits high-frequency information about the object to a spatially-optimized diffractive encoder. The encoder converts and encodes the high-frequency information into low-frequency spatial modes for transmission through air. A diffractive decoder, which i...

An MIT study shows how 40 Hz sensory stimulation with light and sound helps sustain myelination, an essential process in the brain that insulates the signal-sending branches of neurons, called axons, with protective myelin sheaths. Often called the brain’s “white matter,” myelin ensures electrical signal transmission in brain circuits. Demyelination, characterized by the loss of the myelin sheath and the oligodendrocyte cells that form it, leads to impaired axonal function, resulting in brain atrophy and neurodegeneration. Early-stage trials in Alzheimer’s disease patients and studies in mouse models of the disease have suggested that exposure to light and sound at the gamma band frequency of 40 Hz can have a positive impact on the pathology and symptoms from neurodegenerative disorders. “Gamma stimulation promotes a healthy environment,” said researcher Daniela Rodrigues Amorim. “There are several ways we are seeing different effects.” The researchers used the cuprizone mouse model ...