Entries by Katy

Photothermal nanofibres enable safe engineering of therapeutic cells

Nanoparticle-sensitized photoporation is an upcoming approach for the intracellular delivery of biologics, combining high efficiency and throughput with excellent cell viability. However, as it relies on close contact between nanoparticles and cells, its translation towards clinical applications is hampered by safety and regulatory concerns. Here we show that light-sensitive iron oxide nanoparticles embedded in biocompatible […]

Optically Induced Ferroelectric Polarization Switching in a Molecular Ferroelectric with Reversible Photoisomerization

Ferroelectrics usually exhibit temperature-triggered structural changes, which play crucial roles in controlling their physical properties. However, although light is very striking as a non-contact, non-destructive, and remotely controlled external stimuli, ferroelectric crystals with light-triggered structural changes are very rare, which holds promise for optical control of ferroelectric properties. Here, an organic molecular ferroelectric, N-salicylidene-2,3,4,5,6-pentafluoroaniline (SA-PFA), which […]

A High Sensitivity Transparent Ultrasound Transducer Based on PMN-PT for Ultrasound and Photoacoustic Imaging

We recently introduced piezoelectric lithium niobate (LN) based transparent ultrasound transducers (TUT) as a new platform for developing multimodal optical, ultrasound, and photoacoustic imaging (PAI) systems. However, LN based TUT is limited in its signal-to-noise ratio due to material’s low piezoelectricity ( d33 ). In this letter, we report, for the first time, a 0.2-mm-thick transparent lead […]

Re-study of Judd-Ofelt spectroscopic properties of Er3+-doped Gd3(Al, Ga)5O12 single crystal

A previous paper [J. Lumin. 177 (2016) 219] has studied Judd-Ofelt spectroscopic properties of Er3+ (0.5 at%)-doped Gd3(Al, Ga)5O12 garnet single-crystal, and reported the Judd-Ofelt intensity parameters Ω2 = 1.47 × 10−20 cm2, Ω4 = 1.38 × 10−20 cm2 and Ω6 = 1.19 × 10−20 cm2. We have performed a re-study on the Judd-Ofelt spectroscopic properties of a similar garnet single-crystal Er3+(20 at%)-doped Gd3(Al0.4Ga0.6)5O12, and obtained quite different values of Judd-Ofelt intensity parameters Ω2 = (0.34 ± 0.11) × 10−20 cm2, Ω4 = […]

Morphology-dependent resonance enhanced nonlinear photoacoustic effect in nanoparticle suspension: a temporal-spatial model

Photoacoustic (PA) technique has become the focus of intensive research in noninvasive biomedical imaging during the last two decades [1,2]. In most optical imaging applications, the strong optical diffusion coefficient in biological tissues imposes severe challenges on deep penetration imaging. PA technique breaks the optical limit by effectively harnessing both high ultrasonic penetration and excellent […]

Mass Spectrometry Imaging of Arabidopsis thaliana Leaves at the Single-Cell Level by Infrared Laser Ablation Atmospheric Pressure Photoionization (LAAPPI)

In this study, we show that infrared laser ablation atmospheric pressure photoionization mass spectrometry (LAAPPI-MS) imaging with 70 μm lateral resolution allows for the analysis of Arabidopsis thaliana (A. thaliana) leaf substructures ranging from single-cell trichomes and the interveinal leaf lamina to primary, secondary, and tertiary veins. The method also showed its potential for depth profiling analysis […]

Wavelength and pulse energy optimization for detecting hypoxia in photoacoustic imaging of the neonatal brain: a simulation study

Cerebral hypoxia is a severe injury caused by oxygen deprivation to the brain. Hypoxia in the neonatal period increases the risk for the development of neurological disorders, including hypoxic-ischemic encephalopathy, cerebral palsy, periventricular leukomalacia, and hydrocephalus. It is crucial to recognize hypoxia as soon as possible because early intervention improves outcomes. Photoacoustic imaging, using at […]

Charge Transfer, Intersystem Crossing, and Electron Spin Dynamics in a Compact Perylenemonoimide-Phenoxazine Electron Donor–Acceptor Dyad

With phenoxazine (PXZ) as the electron donor and perylene-3,4-dicarboximide (PMI) as the electron acceptor, we prepared a compact, orthogonal electron donor–acceptor dyad (PMI–PXZ) to study the spin–orbit charge transfer-induced intersystem crossing (SOCT-ISC). A weak charge transfer (CT) absorption band, due to S0 → 1CT transition, was observed (ε = 2840 M–1 cm–1 at 554 nm, FWHM: 2850 cm–1), which […]

Optical thermometry through infrared excited green upconversion emissions of Er3+ -Yb3+ co-doped LaAlO3 phosphors

Er3+/Yb3+ single- and co-doped LaAlO3 ceramic phosphors have been synthesized by the conventional solid-state reaction method. The structural, morphological, and optical properties of (z at. %) Er: LaAlO3, (1 at.% Er), (y at.% Yb): LaAlO3, and (7 at.% Yb), (x at.% Er): LaAlO3 samples were investigated. The upconversion (UC) luminescence spectra of (Er3+, Yb3+): LaAlO3 phosphors exhibit strong green and weak red emissions under 973 nm excitation. By measuring the power […]

Solvent Engineering of Colloidal Quantum Dot Inks for Scalable Fabrication of Photovoltaics

Development of colloidal quantum dot (CQD) inks enables single-step spin-coating of compact CQD films of appropriate thickness, enabling the promising performance of CQD photovoltaics (CQDPVs). Today’s highest-performing CQD inks rely on volatile n-butylamine (BTA), but it is incompatible with scalable deposition methods since a rapid solvent evaporation results in irregular film thickness with an uneven surface. […]