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Science China. Life Sciences Dec 2020
Topics: Animals; Biosensing Techniques; China; Diagnostic Imaging; Humans; Interdisciplinary Communication; Optics and Photonics; Optogenetics
PubMed: 33355887
DOI: 10.1007/s11427-020-1858-1 -
Bioconjugate Chemistry May 2020Herein, we report the use of two-photon fluorogenic probes using tetrazine-based bioorthogonal reactions with multicolor emissions that cover nearly all of the visible...
Herein, we report the use of two-photon fluorogenic probes using tetrazine-based bioorthogonal reactions with multicolor emissions that cover nearly all of the visible region. New fluorogenic probes were designed based on donor-acceptor-type naphthalene structures conjugated with a fluorescence-quenching tetrazine moiety for turn-on properties in one- and two-photon fluorescence. Our fluorescent probes showed a moderate to good turn-on ratio after bioorthogonal inverse electron demand Diels-Alder cycloaddition with cyclooctenol in one- and two-photon fluorescence. We successfully applied our probes to mitochondria- and lysosome-selective bioorthogonal imaging in live cells with one-/two-photon and one-photon microscopy, respectively.
Topics: Cell Line, Tumor; Cycloaddition Reaction; Fluorescent Dyes; Heterocyclic Compounds; Humans; Microscopy; Naphthalenes; Photons
PubMed: 32297734
DOI: 10.1021/acs.bioconjchem.0c00197 -
Scientific Reports Jan 2021The present study describes a color-tunable imaging portfolio together with twelve novel coelenterazine (CTZ) analogues. The three groups of CTZ analogues create diverse...
The present study describes a color-tunable imaging portfolio together with twelve novel coelenterazine (CTZ) analogues. The three groups of CTZ analogues create diverse hues of bioluminescence (BL) ranging from blue to far red with marine luciferases. We found that the hue completes the whole color palette in the visible region and shows red-shifted BL with a marine luciferase: for example, Renilla luciferase 8 (RLuc8) and Artificial Luciferase 16 (ALuc16) show 187 nm- and 105 nm-redshifted spectra, respectively, by simply replacing the substrate CTZ with 1d. The optical properties of the new CTZ analogues were investigated such as the kinetic parameters, dose dependency, and luciferase specificity. The 2-series CTZ analogues interestingly have specificity to ALucs and are completely dark with RLuc derivatives, and 3d is highly specific to only NanoLuc. We further determined the theoretical background of the red-shifted BL maximum wavelengths (λ) values according to the extended π conjugation of the CTZ backbone using Density Functional Theory (DFT) calculations. This color-tunable BL imaging system provides a useful multicolor imaging portfolio that efficiently images molecular events in mammalian cells.
Topics: Biotechnology; Luciferases, Renilla; Luminescent Measurements; Molecular Biology; Optics and Photonics
PubMed: 33500496
DOI: 10.1038/s41598-021-81430-1 -
Science (New York, N.Y.) Aug 2022Quantum state engineering, the cornerstone of quantum photonic technologies, mainly relies on spontaneous parametric downconversion and four-wave mixing, where one or...
Quantum state engineering, the cornerstone of quantum photonic technologies, mainly relies on spontaneous parametric downconversion and four-wave mixing, where one or two pump photons spontaneously decay into a photon pair. Both of these nonlinear effects require momentum conservation for the participating photons, which strongly limits the versatility of the resulting quantum states. Nonlinear metasurfaces have subwavelength thickness and allow the relaxation of this constraint; when combined with resonances, they greatly expand the possibilities of quantum state engineering. Here, we generated entangled photons via spontaneous parametric downconversion in semiconductor metasurfaces with high-quality factor, quasi-bound state in the continuum resonances. By enhancing the quantum vacuum field, our metasurfaces boost the emission of nondegenerate entangled photons within multiple narrow resonance bands and over a wide spectral range. A single resonance or several resonances in the same sample, pumped at multiple wavelengths, can generate multifrequency quantum states, including cluster states. These features reveal metasurfaces as versatile sources of complex states for quantum information.
Topics: Photons
PubMed: 36007052
DOI: 10.1126/science.abq8684 -
Journal of Neuroscience Methods Sep 2019Since the advent of optogenetics, the technology development has focused on new methods to optically interact with single nerve cells. This gave rise to the field of... (Review)
Review
Since the advent of optogenetics, the technology development has focused on new methods to optically interact with single nerve cells. This gave rise to the field of photonic neural interfaces, intended as the set of technologies that can modify light radiation in either a linear or non-linear fashion to control and/or monitor cellular functions. This set includes the use of plasmonic effects, up-conversion, electron transfer and integrated light steering, with some of them already implemented in vivo. This article will review available approaches in this framework, with a particular emphasis on methods operating at the single-unit level or having the potential to reach single-cell resolution.
Topics: Animals; Brain; Electrophysiological Phenomena; Nanoparticles; Neurons; Neurosciences; Optics and Photonics; Optogenetics
PubMed: 31319100
DOI: 10.1016/j.jneumeth.2019.108355 -
Journal of Biomedical Optics May 2020Journal of Biomedical Optics editor-in-chief Brian W. Pogue outlines a revision of scope for the journal.
Journal of Biomedical Optics editor-in-chief Brian W. Pogue outlines a revision of scope for the journal.
Topics: Optics and Photonics
PubMed: 32358931
DOI: 10.1117/1.JBO.25.5.050101 -
Nano Letters Oct 2021Optical Fourier transform-based processing is an attractive technique due to the fast processing times and large-data rates. Furthermore, it has recently been...
Optical Fourier transform-based processing is an attractive technique due to the fast processing times and large-data rates. Furthermore, it has recently been demonstrated that certain Fourier-based processors can be realized in compact form factors using flat optics. The flat optics, however, have been demonstrated as static filters where the operator is fixed, limiting the applicability of the approach. Here, we demonstrate a reconfigurable metasurface that can be dynamically tuned to provide a range of processing modalities including bright-field imaging, low-pass and high-pass filtering, and second-order differentiation. The dynamically tunable metasurface can be directly combined with standard coherent imaging systems and operates with a numerical aperture up to 0.25 and over a 60 nm bandwidth. The ability to dynamically control light in the wave vector domain, while doing so in a compact form factor, may open new doors to applications in microscopy, machine vision, and sensing.
Topics: Image Processing, Computer-Assisted; Microscopy; Optics and Photonics
PubMed: 34643401
DOI: 10.1021/acs.nanolett.1c02838 -
Nature Mar 2020
Topics: Neural Networks, Computer; Optics and Photonics; Vision, Ocular
PubMed: 32132685
DOI: 10.1038/d41586-020-00592-6 -
Nature Nanotechnology Apr 2022Optoelectronic effects differentiating absorption of right and left circularly polarized photons in thin films of chiral materials are typically prohibitively small for...
Optoelectronic effects differentiating absorption of right and left circularly polarized photons in thin films of chiral materials are typically prohibitively small for their direct photocurrent observation. Chiral metasurfaces increase the electronic sensitivity to circular polarization, but their out-of-plane architecture entails manufacturing and performance trade-offs. Here, we show that nanoporous thin films of chiral nanoparticles enable high sensitivity to circular polarization due to light-induced polarization-dependent ion accumulation at nanoparticle interfaces. Self-assembled multilayers of gold nanoparticles modified with L-phenylalanine generate a photocurrent under right-handed circularly polarized light as high as 2.41 times higher than under left-handed circularly polarized light. The strong plasmonic coupling between the multiple nanoparticles producing planar chiroplasmonic modes facilitates the ejection of electrons, whose entrapment at the membrane-electrolyte interface is promoted by a thick layer of enantiopure phenylalanine. Demonstrated detection of light ellipticity with equal sensitivity at all incident angles mimics phenomenological aspects of polarization vision in marine animals. The simplicity of self-assembly and sensitivity of polarization detection found in optoionic membranes opens the door to a family of miniaturized fluidic devices for chiral photonics.
Topics: Animals; Electrons; Gold; Metal Nanoparticles; Optics and Photonics; Photons
PubMed: 35288671
DOI: 10.1038/s41565-022-01079-3 -
Optics Express Jun 2022We propose an approach to generate neuron-like spikes of vertical-cavity surface-emitting laser (VCSEL) by multi-frequency switching. A stable temporal spiking sequence...
We propose an approach to generate neuron-like spikes of vertical-cavity surface-emitting laser (VCSEL) by multi-frequency switching. A stable temporal spiking sequence has been realized both by numerical simulations and experiments with a pulse width of sub-nanosecond, which is 8 orders of magnitude faster than ones from biological neurons. Moreover, a controllable spiking coding scheme using multi-frequency switching is designed and a sequence with 20 symbols is generated at the speed of up to 1 Gbps by experiment. Furthermore, we investigate the factors related to time delay of spiking generation, including injection strength and frequency detuning. With proper manipulation of detuning frequency, the spiking generation delay can be controlled upto 60 ns, which is 6 times longer than the delay controlled by intensity. The multi-frequency switching provides another manipulation dimension for spiking generation and will be helpful to exploit the abundant spatial-temporal features of spiking neural network. We believe the proposed VCSEL-neuron, as a single physical device for generating spiking signals with variable time delay, will pave the way for future photonic spiking neural networks.
Topics: Lasers; Neural Networks, Computer; Neurons; Optics and Photonics; Photons
PubMed: 36224875
DOI: 10.1364/OE.456583