3 research outputs found
Subnanogram Mass Measurements on Plasmonic Nanoparticles for Temperature-Programmed Thermal Analysis
Ultrasensitive thermogravimetric analysis of adsorbed organic
molecules has been achieved on an ordered array of gold nanoparticles
used as a novel plasmonic nanobalance. The extinction peaks of the
resonating surface plasmon of nanoparticle arrays shift upon loading
molecules and return to the original position after a linear temperature
rise process. A good correlation exists between the film thickness
and magnitude of peak shifts. The detection range of plasmonic nanobalance
derived from our results can reach a subnanogram level (1.8 pg on
an active area of 100 μm<sup>2</sup>), which is much lower than
those of mechanical or electronic mass-measuring devices. Such high
mass sensitivity, combined with the remote detection capability and
high-temperature operation of plasmonic sensors, allows the in situ
detections of the masses of loaded material and thermally desorbed
molecules
Three-Dimensional Microtissue Assay for High-Throughput Cytotoxicity of Nanoparticles
Traditional in vitro nanotoxicity researches are conducted
on cultured
two-dimensional (2D) monolayer cells and thereby cannot reflect organism
response to nanoparticle toxicities at tissue levels. This paper describes
a new, high-throughput approach to test in vitro nanotoxicity in three-dimensional
(3D) microtissue array, where microtissues are formed by seeding cells
in nonsticky microwells, and cells are allowed to aggregate and grow
into microtissues with defined size and shape. Nanoparticles attach
and diffuse into microtissues gradually, causing radial cytotoxicity
among cells, with more cells being killed on the outer layers of the
microtissue than inside. Three classical toxicity assays [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium
bromide] (MTT), glucose-6-phosphate dehydrogenase (G6DP), and calcein
AM and ethidium homodimer (calcein AM/EthD-1)] have been adopted to
verify the feasibility of the proposed approach. Results show that
the nanotoxicities derived from this method are significantly lower
than that from traditional 2D cultured monolayer cells (<i>p</i> < 0.05). Equipped with a microplate reader or a microscope, the
nanotoxicity assay could be completed automatically without transferring
the microtissue, ensuring the reliability of toxicity assay. The proposed
approach provides a new strategy for high-throughput, simple, and
accurate evaluation of nanoparticle toxicities by combining 3D microtissue
array with a panel of classical toxicity assays
Visible-Light-Driven, Radical-Triggered Tandem Cyclization of <i>o</i>‑Hydroxyaryl Enaminones: Facile Access to 3‑CF<sub>2</sub> /CF<sub>3</sub>‑Containing Chromones
A practical and straightforward
synthetic route to construct a
variety of 3-CF<sub>2</sub>/CF<sub>3</sub>-containing chromones via
photoredox catalysis was developed. This novel protocol features a
visible-light-induced radical-triggered tandem cyclization