Contrast-enhanced fluorescence microscope by LED integrated excitation cubes

Abstract

Fluorescence microscopy is a powerful tool for scientists to observe the microscopic world, and a fluorescence excitation light source is one of the most critical components. To compensate for the short operation lifetime, integrated light sources, and low excitation efficiency of conventional light sources such as mercury, halogen, and xenon lamps, we designed an LED-integrated excitation cube (LEC) with a decentralized structure and high optical power density. Using a Fresnel lens, the light from the light-emitting diode (LED) was effectively focused within a 15 mm mounting distance to achieve high-efficiency illumination. LEC can be easily designed in the shape of fluorescence filter cubes for installation in commercial fluorescence microscopes. LECs' optical efficiency is 1-2 orders of magnitude higher than that of mercury lamps; therefore, high-quality fluorescence imaging with spectral coverage from UV to red can be achieved. By replacing conventional fluorescence filter cubes, LEC can be easily installed on any commercial fluorescence microscope. A built-in LEC driver can identify the types of LEDs in different spectral bands to adopt the optimal operating current and frequency of pulses. Moreover, high-contrast images can be achieved in pulse mode by time-gated imaging of long-lifetime luminescence.

Free-moving-state microscopic imaging of cerebral oxygenation and hemodynamics with a photoacoustic fiberscope

“…Multi-modal or multi-contrast head-mounted microscopes have been developed for freely moving rodents to provide a comprehensive understanding of cerebral neurological and hemodynamic activities 45 . The photoacoustic fiberscope can be integrated with existing microscopes by utilizing the common optical path 46 , 47 . This is because the photoacoustic fiberscope does not require an optical/acoustic confocal scheme, and the small-sized sensor can be placed away from the laser beam.…”

Lanthanide Complex for Single-Molecule Fluorescent in Situ Hybridization and Background-Free Imaging

“…Time-gated (TG) luminescence microscopy was used to collect background-free europium-probe-labeled cell and tissue images. The detailed schematic illustration of the TG microscopy system has been demonstrated in our previous works. , Specifically, a 340 nm light-emitting diode (LED) was used to excite the samples. The LED was synchronized with an optical chopper, which was used to remove short-lived signal.…”

“…Moreover, the prolonged lifetime of lanthanide ions allows for the implementation of time-gated luminescent microscopy, effectively eliminating short-lived autofluorescence. 20,21 In our previous work, we developed BHHBCB yl)benzyl]-4-chlorosulfobenzene)•Eu 3+ probes, which demonstrated the enhanced contrast by 2-fold and 3-fold for cell imaging and tissue imaging. 22 Here, we developed a type of smFISH probe with branched azide-dUTP moieties to couple multiple highly stained BHHBCB•Eu 3+ complexes through specific reactions.…”

“…A key advantage of lanthanide probes is their ability to mitigate fluorescence quenching, even at high probe densities, due to the large Stokes shift of typically over 200 nm. , This characteristic enables the detection of weak signals and the visualization of single molecules, thereby providing a highly sensitive and specific representation of the target nucleic acid sequences. Moreover, the prolonged lifetime of lanthanide ions allows for the implementation of time-gated luminescent microscopy, effectively eliminating short-lived autofluorescence. , In our previous work, we developed BHHBCB (1,2-bis­[4′-(1″,1″,1″,2″,2″,3″,3″-heptachlor-6″-hexanediol-6″-yl)­benzyl]-4-chlorosulfobenzene)·Eu 3+ probes, which demonstrated the enhanced contrast by 2-fold and 3-fold for cell imaging and tissue imaging …”

A multifunctional optoelectronic device based on 2D material with wide bandgap

“…Alignment of geometrically anisotropic 2D materials can endow the resultant dispersion with extremely large optical anisotropy, allowing for many exceptional potentials in diverse applications. For instance, they can be utilized in the assembly of special functional materials, unconventional optical modulation, and detection, such as constructing optical hydrogels, enabling deep ultraviolet modulation, and facilitating visual ion chemical sensing [8][9][10][11][12] .…”