ORCID Profile
0000-0003-4620-7771
Current Organisation
The Francis Crick Institute
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Publisher: SPIE
Date: 05-03-2019
DOI: 10.1117/12.2513733
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1NA00765C
Abstract: We report a tailor-made multiplexed super-resolution imaging method using the lifetime fingerprints from luminescent nanoparticles, which can resolve the particles within the diffraction-limited spots and enable higher multiplexing capacity in space.
Publisher: Springer Science and Business Media LLC
Date: 25-11-2020
Publisher: American Chemical Society (ACS)
Date: 26-08-2022
Publisher: American Chemical Society (ACS)
Date: 18-05-2023
Publisher: Wiley
Date: 17-04-2021
Abstract: Point spread function (PSF) engineering by an emitter's response can code higher‐spatial‐frequency information of an image for microscopy to achieve super‐resolution. However, complexed excitation optics or repetitive scans are needed, which explains the issues of low speed, poor stability, and operational complexity associated with the current laser scanning microscopy approaches. Here, the erse emission responses of upconversion nanoparticles (UCNPs) are reported for super‐resolution nanoscopy to improve the imaging quality and speed. The method only needs a doughnut‐shaped scanning excitation beam at an appropriate power density. By collecting the four‐photon emission of single UCNPs, the high‐frequency information of a super‐resolution image can be resolved through the doughnut‐emission PSF. Meanwhile, the two‐photon state of the same nanoparticle is oversaturated, so that the complementary lower‐frequency information of the super‐resolution image can be simultaneously collected by the Gaussian‐like emission PSF. This leads to a method of Fourier‐domain heterochromatic fusion, which allows the extended capability of the engineered PSFs to cover both low‐ and high‐frequency information to yield optimized image quality. This approach achieves a spatial resolution of 40 nm, 1/24th of the excitation wavelength. This work suggests a new scope for developing nonlinear multi‐color emitting probes in super‐resolution nanoscopy.
Publisher: Research Square Platform LLC
Date: 14-10-2022
DOI: 10.21203/RS.3.RS-2160647/V1
Abstract: Precise force measurement is critical to probing biological events and physics processes, spanning from molecular motor’s motion to the Casimir effect 1 and the detection of gravitational wave 2 . Yet, despite extensive technology developments, the 3D nanoscale measurement of weak forces in aqueous solutions poses a significant challenge. Techniques that rely on the optically trapped nanoprobe are beset with difficulties, including low light scattering for force measuring and high localization error from their Brownian motion. Here, we report the measurement of the long-distance electrodynamic force on single nanocrystals suspended in aqueous solution with only 11 net charges. To achieve this, we develop an upconversion photonic force microscope that encompasses a diffraction-limited tracking-based force sensing theory and the advance of lanthanide ion resonance force probe 3,4 . The tracking method is based on neural network empowered super-resolution localization, where the position of force probe is extracted from the optical astigmatism modified point spread functon(PSF), enabling the measurement of trap stiffness for nanoparticles through equipartition theorem with a force sensitivity down to 592.9 attoNewtons (aN), that is, 5 times lower than the reported best sensitivity value 5 . We further demonstrate that the technology can measure a single nanocrystal's electrophoresis force and zeta potential, experimentally verifying Loeb's empirical relationship. This work offers new opportunities for detecting single-charge dynamics over long-distance and sub-cellular single molecular level biomechanical force.
Publisher: American Chemical Society (ACS)
Date: 31-03-2021
Publisher: SPIE-Intl Soc Optical Eng
Date: 17-04-2019
Publisher: Springer Science and Business Media LLC
Date: 22-03-2023
DOI: 10.1038/S41377-023-01127-0
Abstract: Narrowband red, green, blue self-filtering perovskite photodetectors and a broadband white photodetector are incorporated into a single pixel imaging camera to mimic the long-, medium-, and short-wavelength cone cells and rod cells in human visual system, leading to the demonstration of high-resolution color images in diffuse mode.
Publisher: Wiley
Date: 14-01-2020
Abstract: Cancer spheroids have structural, functional, and physiological similarities to the tumor, and have become a low-cost in vitro model to study the physiological responses of single cells and therapeutic efficacy of drugs. However, the tiny spheroid, made of a cluster of high-density cells, is highly scattering and absorptive, which prevents light microscopy techniques to reach the depth inside spheroids with high resolution. Here, a method is reported for super-resolution mapping of single nanoparticles inside a spheroid. It first takes advantage of the self-healing property of a "nondiffractive" doughnut-shaped Bessel beam from a 980 nm diode laser as the excitation, and further employs the nonlinear response of the 800 nm emission from upconversion nanoparticles, so that both excitation and emission at the near-infrared can experience minimal loss through the spheroid. These strategies lead to the development of a new nanoscopy modality with a resolution of 37 nm, 1/26th of the excitation wavelength. This method enables mapping of single nanoparticles located 55 µm inside a spheroid, with a resolution of 98 nm. It suggests a solution to track single nanoparticles and monitor their release of drugs in 3D multicellar environments.
Publisher: American Chemical Society (ACS)
Date: 24-01-2020
DOI: 10.1021/ACS.JPCLETT.9B03838
Abstract: Nonblinking, nonbleaching, and superbright single upconversion nanoparticles have been recently discovered with nonlinear power-dependent properties and can be switchable under dual-beam excitations, which are ideal for super-resolution microscopy, single-molecule tracking, and digital assays. Here, we report that the brightness of Nd
Publisher: Optica Publishing Group
Date: 20-10-2021
Abstract: Ghost imaging captures 2D images with a point detector instead of an array sensor. It could therefore solve the challenge of building cameras in wave bands where sensors are difficult and expensive to produce and could open up more routine THz, near-infrared, lifetime, and hyperspectral imaging simply by using single-pixel detectors. Traditionally, ghost imaging retrieves the image of an object offline by correlating measured light intensities with pre-designed illuminating patterns. Here we present a “self-evolving” ghost imaging (SEGI) strategy for imaging objects bypassing offline post-processing. It also offers the capability to image objects in turbid media. By inspecting the optical feedback, we evaluate the illumination patterns by a cost function and generate offspring illumination patterns that mimic the object’s image, bypassing the reconstruction process. At the initial evolving state, the object’s “genetic information” is stored in the patterns. At the following imaging stage, the object’s image ( 48 × 48 p i x e l s ) can be updated at a 40 Hz imaging rate. We numerically and experimentally demonstrate this concept for static and moving objects. The frame-memory effect between the self-evolving illumination patterns provided by the genetic algorithm enables SEGI imaging through turbid media. We further demonstrate this capability by imaging an object placed in a container filled with water and sand. SEGI shows robust and superior imaging power compared with traditional computational ghost imaging. This strategy could enhance ghost imaging in applications such as remote sensing, imaging through scattering media, and low-irradiative biological imaging.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7NR08979A
Abstract: The integrated methods of core shell upconversion nanoparticle synthesis, thermal annealing and gold dewetting produce gold-decorated upconversion nanoparticles with enhanced emission.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2021
Publisher: SPIE
Date: 20-08-2020
DOI: 10.1117/12.2569754
Publisher: American Chemical Society (ACS)
Date: 08-06-2022
DOI: 10.1021/ACS.JPCLETT.2C01186
Abstract: Lanthanide-doped upconversion nanoparticles (UCNPs) have enabled a broad range of emerging nanophotonics and biophotonics applications. Here, we provide a quantitative guide to the optimum concentrations of Yb
Publisher: Springer Science and Business Media LLC
Date: 18-02-2021
DOI: 10.1038/S41565-021-00852-0
Abstract: Optical tweezers are widely used in materials assembly
Publisher: American Chemical Society (ACS)
Date: 25-03-2020
Publisher: American Chemical Society (ACS)
Date: 18-08-2021
Publisher: Springer Science and Business Media LLC
Date: 16-07-2021
DOI: 10.1038/S41467-021-24664-X
Abstract: Photon upconversion of near-infrared (NIR) irradiation into ultraviolet-C (UVC) emission offers many exciting opportunities for drug release in deep tissues, photodynamic therapy, solid-state lasing, energy storage, and photocatalysis. However, NIR-to-UVC upconversion remains a daunting challenge due to low quantum efficiency. Here, we report an unusual six-photon upconversion process in Gd 3+ /Tm 3+ -codoped nanoparticles following a heterogeneous core-multishell architecture. This design efficiently suppresses energy consumption induced by interior energy traps, maximizes cascade sensitizations of the NIR excitation, and promotes upconverted UVC emission from high-lying excited states. We realized the intense six-photon-upconverted UV emissions at 253 nm under 808 nm excitation. This work provides insight into mechanistic understanding of the upconversion process within the heterogeneous architecture, while offering exciting opportunities for developing nanoscale UVC emitters that can be remotely controlled through deep tissues upon NIR illumination.
Publisher: Springer Science and Business Media LLC
Date: 17-08-2018
DOI: 10.1038/S41467-018-05842-W
Abstract: Multiphoton fluorescence microscopy (MPM), using near infrared excitation light, provides increased penetration depth, decreased detection background, and reduced phototoxicity. Using stimulated emission depletion (STED) approach, MPM can bypass the diffraction limitation, but it requires both spatial alignment and temporal synchronization of high power (femtosecond) lasers, which is limited by the inefficiency of the probes. Here, we report that upconversion nanoparticles (UCNPs) can unlock a new mode of near-infrared emission saturation (NIRES) nanoscopy for deep tissue super-resolution imaging with excitation intensity several orders of magnitude lower than that required by conventional MPM dyes. Using a doughnut beam excitation from a 980 nm diode laser and detecting at 800 nm, we achieve a resolution of sub 50 nm, 1/20th of the excitation wavelength, in imaging of single UCNP through 93 μm thick liver tissue. This method offers a simple solution for deep tissue super resolution imaging and single molecule tracking.
Publisher: Research Square Platform LLC
Date: 28-10-2020
DOI: 10.21203/RS.3.RS-88155/V1
Abstract: Photon upconversion of near-infrared (NIR) irradiation into deep-ultraviolet (UV) emission offers many exciting opportunities for drug release in deep tissues, photodynamic therapy, solid-state lasing, energy storage, and photocatalysis. However, NIR-to-deep-UV upconversion remains a daunting challenge due to low quantum efficiency. Here, we report an unusual six-photon upconversion process in Gd3+/Tm3+-codoped nanoparticles comprising a heterogeneous, core-multishell nanostructure. This multishell design efficiently suppresses energy consumption induced by interior energy traps, maximizes cascade sensitizations of the NIR excitation, and promotes upconverted deep-UV emission from high-lying excited states. We released the intense six-photon-upconverted UV emissions at 253 nm under 808-nm excitation. This work provides new insight into mechanistic understanding of the upconversion process within the heterogeneous architecture, while offering exciting opportunities for developing nanoscale deep-UV emitters that can be remotely controlled in deep tissues upon NIR illumination.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Chaohao Chen.