Bio Photonics Research

A research team at Nanyang Technological University, Singapore (NTU Singapore) has developed a wearable sensor based on microlasers to measure biomarkers found in sweat. The bandage-like device could provide a way to monitor blood sugar levels noninvasively. Human sweat contains biomarkers such as glucose, lactate, and urea that indicate various health conditions and can be collected in a noninvasive and painless manner, making it ideal for daily monitoring, the researchers said. Diabetic patients typically use an invasive finger prick test to self-monitor blood glucose levels. A small drop is drawn from the finger and put into contact with a strip which is inserted into a portable glucose meter for reading. Alternatively, there are sensor-based monitoring devices, which can be expensive and rigid and must be attached to a patient’s skin over prolonged periods of time. By encapsulating a microlaser in liquid crystal droplets and embedding the liquid within a soft hydrogel film, the...

A Molecular engineering spearheaded by two groups at the European Molecular Biology Laboratory (EMBL) has developed an approach to create photoacoustic probes for neuroscience applications. Scientists can learn more about biological processes by tracking certain chemicals, such as ions or biomolecules. Photoacoustic probes can act as ‘reporters’ for hard-to-detect chemicals by binding to them specifically. The probes can then absorb light when excited by lasers and emit sound waves that can be detected by specialized imaging equipment. For neuroscience applications, however, researchers have so far been unable to engineer targeted reporters that can visualize brain functions tailored for photoacoustics. “Photoacoustics offer a way to capture imagery of an entire mouse brain, but we just lacked the right probes to visualize a neuron’s activity,” said Robert Prevedel, an EMBL group leader and a senior author on the paper. To overcome this challenge, Prevedel enlisted the help of fello...

A team at Heriot-Watt University, led by professor Christian Brahms, is developing a light source for extremely fast laser pulses that will enable scientists to observe some of the fastest processes in the natural world as they occur. The new laser light source will capture natural processes like light absorption in photosynthesis in attoseconds. The project, which is called FASTER — short for Flexible Attosecond Soliton Transients for Extreme Resolution — will build on the EUV attosecond technology that received the Nobel Prize in Physics in 2023. Brahms and his team will design and build a laser light source that mimics natural sunlight, but in extremely short flashes. “My aim is to create laser pulses with similar extremely short duration to conventional attosecond science sources, but at the same ultraviolet and visible wavelengths as we get from the sun,” he said. FASTER will bring attosecond time resolution to ultrafast spectroscopy experiments in the UV, visible, and IR region...

A research team from Nanjing University has developed a solution that improves metalens performance in and for microscopy applications. The researchers’ metalens-based microscope achieves both a wide field of view (FOV) and high-resolution imaging, addressing the inherent trade-off between these two critical parameters that, according to the researchers, has prevented metalenses to date from achieving performance comparable to conventional microscopes. Metalenses face significant challenges in practical microscopy applications. Off-axis aberrations, which severely restrict metalens FOV and resolution capabilities, are the primary limitations to the use of metalenses in practical microscopy. In their system architecture, the researchers used a doublet configuration of two metalenses on opposite sides of a transparent silica substrate combined with annular illumination. The two metalenses consist of silicon nitride nano-fins, crafted as high-aspect-ratio squares with precise dimension...

Researchers at the University of Tokyo have increased the measurement rate of Raman spectroscopy by 100-fold. Since the measurement rate of the technique has been a major limitation, the improvement is expected to aid advancements in multiple fields relying on the identification of molecules and cells , such as biomedical diagnostics and material analytics. As a mode of identification for cells and molecules, Raman spectroscopy is widely used, but it’s limited in its ability to keep up with the speed of changes in certain chemical and physical reactions due to the low scattering cross section. Over the last decade, various broadband-coherent Raman scattering spectroscopy techniques have been developed to address the limitation, achieving a measurement of 500 kSpectra/s (kilospectra per second). In order to further improve the measurement rate, the team built a system from scratch, leveraging a mode-locked ytterbium laser system developed by Takuro Ideguchi and his team at the Instit...

Bacterial resistance to antibiotics is a growing challenge for the healthcare and e nvironmental sectors. Bacterial persistence is usually the first step leading to resistance, which involves a change in an organism’s genome. In the future, it may be possible to address antibiotic persistence and resistance by using light to regulate bacterial response to antibiotics. A technique developed at the Polytechnic University of Milan (Politecnico di Milano), by a team participating in the Engineering of Bacteria to See Light (EOS) project, allows bacteria to sense light and convert light energy into electrical signals across the bacterial membrane, without the need for genetic modification. To demonstrate photocontrol of bacterial membrane potential, the researchers attached phototransducing molecules to bacterial surfaces to make the bacteria light-responsive. When the researchers exposed the phototransducers to light, the electrical potential of the bacterial membrane changed. The researc...