Single-Step Photochemical Formation of Near-Infrared-Absorbing Gold Nanomosaic within PNIPAm Microgels: Candidates for Photothermal Drug Delivery

This work demonstrates the dynamic potential for tailoring the surface plasmon resonance (SPR), size, and shapes of gold nanoparticles (AuNPs) starting from an Au(I) precursor, chloro(dimethyl sulfide)gold (I) (Au(Me2S)Cl), in lieu of the conventional Au(III) precursor hydrogen tetrachloroaurate (III) hydrate (HAuCl4). Our approach presents a one-step method that permits regulation of an Au(I) precursor to form either visible-absorbing gold nanospheres or near-infrared-window (NIRW)-absorbing anisotropic AuNPs. A collection of shapes is obtained for the NIR-absorbing AuNPs herein, giving rise to spontaneously formed nanomosaic (NIR-absorbing anisotropic gold nanomosaic, NIRAuNM) without a dominant geometry for the tesserae elements that comprise the mosaic. Nonetheless, NIRAuNM exhibited high stability; one test sample remains stable with the same SPR absorption profile 7 years post-synthesis thus far. These NIRAuNM are generated within thermoresponsive poly(N-isopropylacrylamide) (PNIPAm) microgels, without the addition of any growth-assisting surfactants or reducing agents. Our directed-selection methodology is based on the photochemical reduction of a light-, heat-, and water-sensitive Au(I) precursor via a disproportionation mechanism. The NIRAuNM stabilized within the thermoresponsive microgels demonstrates a light-activated size decrease of the microgels. On irradiation with a NIR lamp source, the percent decrease in the size of the microgels loaded with NIRAuNM is at least five times greater compared to the control microgels. The concept of photothermal shrinkage of hybrid microgels is further demonstrated by the release of a model luminescent dye, as a drug release model. The absorbance and emission of the model dye released from the hybrid microgels are over an order of magnitude higher compared to the absorbance and emission of the dye released from the unloaded-control microgels.

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Purification of Urokinase from Complex Mixtures Using Immobilized Monoclonal Antibody Against Urokinase Light Chain

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657308 ◽

1983 ◽

Vol 49 (01) ◽

pp. 024-027 ◽

Cited By ~ 20

Author(s):

David Vetterlein ◽

Gary J Calton

Keyword(s):

Monoclonal Antibody ◽

Light Chain ◽

Culture Media ◽

Biological Fluids ◽

Single Step ◽

High Yield ◽

Step Method ◽

Commercial Preparation ◽

E Coli ◽

Tissue Culture Media

SummaryThe preparation of a monoclonal antibody (MAB) against high molecular weight (HMW) urokinase light chain (20,000 Mr) is described. This MAB was immobilized and the resulting immunosorbent was used to isolate urokinase starting with an impure commercial preparation, fresh urine, spent tissue culture media, or E. coli broth without preliminary dialysis or concentration steps. Monospecific antibodies appear to provide a rapid single step method of purifying urokinase, in high yield, from a variety of biological fluids.

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Post-Synthesis Modification of Photoluminescent and Electrochemiluminescent Au Nanoclusters with Dopamine

Nanomaterials ◽

10.3390/nano11010046 ◽

2020 ◽

Vol 11 (1) ◽

pp. 46

Author(s):

Jae Hyun Kim ◽

Joohoon Kim

Keyword(s):

Near Infrared ◽

Au Nanoclusters ◽

Metallic Core ◽

Thiolate Ligand ◽

Pl Intensity ◽

Post Synthesis

Here, we report a post-synthesis functionalization of the shell of Au nanoclusters (NCs) synthesized using glutathione as a thiolate ligand. The as-synthesized Au NCs are subjected to the post-synthesis functionalization via amidic coupling of dopamine on the cluster shell to tailor photoluminescence (PL) and electrochemiluminescence (ECL) features of the Au NCs. Because the NCs’ PL at ca. 610 nm is primarily ascribed to the Au(I)-thiolate (SG) motifs on the cluster shell of the NCs, the post-synthesis functionalization of the cluster shell enhanced the PL intensity of the Au NCs via rigidification of the cluster shell. In contrast to the PL enhancement, the post-synthesis modification of the cluster shell does not enhance the near-infrared (NIR) ECL of the NCs because the NIR ECL at ca. 800 nm is ascribed to the Au(0)-SG motifs in the metallic core of the NCs.

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One-Pot Hydrothermal Synthesis of Victoria Green (Ca3Cr2Si3O12) Nanoparticles in Alkaline Fluids and Its Colour Hue Characterisation

Nanomaterials ◽

10.3390/nano11020521 ◽

2021 ◽

Vol 11 (2) ◽

pp. 521

Author(s):

Juan Carlos Rendón-Angeles ◽

Zully Matamoros-Veloza ◽

Jose Luis Rodríguez-Galicia ◽

Gimyeong Seong ◽

Kazumichi Yanagisawa ◽

...

Keyword(s):

Near Infrared ◽

Single Step ◽

Spectral Space ◽

Infrared Reflectance ◽

Hydrothermal Preparation ◽

Near Infrared Reflectance ◽

One Pot ◽

Factors Affecting ◽

B Values ◽

Alkaline Conditions

One-pot hydrothermal preparation of Ca3Cr2Si3O12 uvarovite nanoparticles under alkaline conditions was investigated for the first time. The experimental parameters selected for the study considered the concentration of the KOH solvent solution (0.01 to 5.0 M), the agitation of the autoclave (50 rpm), and the nominal content of Si4+ (2.2–3.0 mole). Fine uvarovite particles were synthesised at 200 °C after a 3 h interval in a highly concentrated 5.0 M KOH solution. The crystallisation of single-phase Ca3Cr2Si3O12 particles proceeded free of by-products via a one-pot process involving a single-step reaction. KOH solutions below 2.5 M and water hindered the crystallisation of the Ca3Cr2Si3O12 particles. The hydrothermal treatments carried out with stirring (50 rpm) and non-stirring triggered the crystallisation of irregular anhedral particles with average sizes of 8.05 and 12.25 nm, respectively. These particles spontaneously assembled into popcorn-shaped agglomerates with sizes varying from 66 to 156 nm. All the powders prepared by the present method exhibited CIE-L*a*b* values that correspond to the Victoria green colour spectral space and have a high near infrared reflectance property. The particle size and structural crystallinity are factors affecting the Victoria pigment optical properties, such as CIE-L*a*b* values, green tonality, and near-infrared reflectance.

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High-resolution limited-angle phase tomography of dense layered objects using deep neural networks

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1821378116 ◽

2019 ◽

Vol 116 (40) ◽

pp. 19848-19856 ◽

Cited By ~ 12

Author(s):

Alexandre Goy ◽

Girish Rughoobur ◽

Shuai Li ◽

Kwabena Arthur ◽

Akintunde I. Akinwande ◽

...

Keyword(s):

Integrated Circuit ◽

Deep Neural Networks ◽

Tomographic Reconstruction ◽

Synthetic Data ◽

Single Step ◽

Training Set ◽

Step Method ◽

3 Dimensional ◽

Dimensional Reconstruction ◽

Optical Domain

We present a machine learning-based method for tomographic reconstruction of dense layered objects, with range of projection angles limited to ±10○. Whereas previous approaches to phase tomography generally require 2 steps, first to retrieve phase projections from intensity projections and then to perform tomographic reconstruction on the retrieved phase projections, in our work a physics-informed preprocessor followed by a deep neural network (DNN) conduct the 3-dimensional reconstruction directly from the intensity projections. We demonstrate this single-step method experimentally in the visible optical domain on a scaled-up integrated circuit phantom. We show that even under conditions of highly attenuated photon fluxes a DNN trained only on synthetic data can be used to successfully reconstruct physical samples disjoint from the synthetic training set. Thus, the need for producing a large number of physical examples for training is ameliorated. The method is generally applicable to tomography with electromagnetic or other types of radiation at all bands.

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