scholarly journals Assessment of Altered Fucosylation of Serum α-1-Acid Glycoprotein in Hepatocellular Carcinoma Patients by Gold-Nanoparticle Aggregation Immunoassay

2018 ◽  
Vol 15 (3) ◽  
pp. 263-271
Author(s):  
Partha Pratim Bose ◽  
Urmimala Chatterjee ◽  
Bishnu Pada Chatterjee
Keyword(s):  
Hepatocellular Carcinoma ◽  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Plasmon Band ◽  
Acid Glycoprotein ◽  
Aleuria Aurantia Lectin ◽  
Gold Nanoparticle Aggregation ◽  
Potential Applications ◽  
Visual Assay ◽  
Protein Serum

Gold nanoparticles have attracted considerable attention due to their unique properties and potential applications as optical probes. When proteins that are adsorbed on gold nanoparticles subsequently get cross-linked by any interaction specific to that protein, the size of the aggregates increases and this enhancement of size have been used for sensitive, convenient and powerful tool to monitor the presence of the specific cross-linkers. Dynamic light scattering (DLS) is a technique that is routinely used for detecting aggregation in macromolecular solutions. In this work, we first applied DLS to identify specific glycoprotein–lectin interactions exclusively present in the serum of hepatocellular carcinoma patients compared to healthy controls that showed the altered fucosylation of a serum protein, Serum α-1-Acid glycoprotein. Further, based on the DLS data a simple, rapid, serological assay was developed based on antibody coated gold nanoparticle and fucose binding lectin (Aleuria aurantia lectin) as linker to asses the level of fucosylation of α-1-acid glycoprotein. As a consequence of the triggered aggregation of the GNP probes in presence of lectin, plasmon band was shifted from red to blue, which colorimetrically reported the enhanced fucosylation of α-1-acid glycoprotein and formed the basis of a rapid visual assay for hepatocellular carcinoma.

scholarly journals CRISPR/Cas12a-mediated gold nanoparticle aggregation for colorimetric detection of SARS-CoV-2

2021 ◽  
Author(s):  
Yiren Cao ◽  
Jinjun Wu ◽  
Bo Pang ◽  
Hongquan Zhang ◽  
X. Chris Le
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Colorimetric Detection ◽  
Isothermal Amplification ◽  
Nanoparticle Aggregation ◽  
Cleavage Activity ◽  
Gold Nanoparticle Aggregation

The trans-cleavage activity of the target-activated CRISPR-Cas12a liberated an RNA crosslinker from a molecular transducer, which facilitated assembly of gold nanoparticles. Integration of the molecular transducer with isothermal amplification and...

scholarly journals Air-Filled Bubbles Stabilized by Gold Nanoparticle/Photodynamic Dye Hybrid Structures for Theranostics

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 415
Author(s):  
Roman Barmin ◽  
Polina Rudakovskaya ◽  
Olga Gusliakova ◽  
Olga Sindeeva ◽  
Ekaterina Prikhozhdenko ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Photoacoustic Imaging ◽  
Ultrasound Contrast Agents ◽  
Zinc Phthalocyanine ◽  
Hybrid Structures ◽  
Potential Applications ◽  
Average Size ◽  
The Impact ◽  
Potential Use

Microbubbles have already reached clinical practice as ultrasound contrast agents for angiography. However, modification of the bubbles’ shell is needed to produce probes for ultrasound and multimodal (fluorescence/photoacoustic) imaging methods in combination with theranostics (diagnostics and therapeutics). In the present work, hybrid structures based on microbubbles with an air core and a shell composed of bovine serum albumin, albumin-coated gold nanoparticles, and clinically available photodynamic dyes (zinc phthalocyanine, indocyanine green) were shown to achieve multimodal imaging for potential applications in photodynamic therapy. Microbubbles with an average size of 1.5 ± 0.3 μm and concentration up to 1.2 × 109 microbubbles/mL were obtained and characterized. The introduction of the dye into the system reduced the solution’s surface tension, leading to an increase in the concentration and stability of bubbles. The combination of gold nanoparticles and photodynamic dyes’ influence on the fluorescent signal and probes’ stability is described. The potential use of the obtained probes in biomedical applications was evaluated using fluorescence tomography, raster-scanning optoacoustic microscopy and ultrasound response measurements using a medical ultrasound device at the frequency of 33 MHz. The results demonstrate the impact of microbubbles’ stabilization using gold nanoparticle/photodynamic dye hybrid structures to achieve probe applications in theranostics.

Interference of Gold Nanoparticles with In vitro Endotoxin Detection Assays

2020 ◽  
Vol 16 (2) ◽  
pp. 204-213 ◽  
Author(s):  
Melissa A. Vetten ◽  
Mary Gulumian
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Surface Reactivity ◽  
In Vitro Assays ◽  
Limulus Amebocyte Lysate ◽  
Chromogenic Assay ◽  
Nanoparticle Suspensions ◽  
Endotoxin Contamination ◽  
Factor C

Background: Endotoxin-free engineered nanoparticle suspensions are imperative for their successful applications in the field of nanomedicine as well as in the investigations in their toxicity. Gold nanoparticles are known to interfere with various in vitro assays due to their optical properties and potential for surface reactivity. In vitro endotoxin testing assays are known to be susceptible to interference caused by the sample being tested. Objective: This study aimed to identify a preferred assay for the testing of endotoxin contamination in gold nanoparticle suspensions. Methods: The interference by gold nanoparticles on three assays namely, the commonly used limulus amebocyte lysate chromogenic assay, the limulus amebocyte lysate gel-clot method, and the less common recombinant Factor C (rFC) assay, was tested. Results: Possible interference could be observed with all three assays. The interference with the absorbance- based chromogenic assay could not be overcome by dilution; whilst the qualitative nature of the gel-clot assay excluded the possibility of distinguishing between a false positive result due to enhancement of the sensitivity of the assay, and genuine endotoxin contamination. However, interference with the rFC assay was easily overcome through dilution. Conclusion: The rFC assay is recommended as an option for endotoxin contamination detection in gold nanoparticle suspensions.

Fluorescence biosensor for Salmonella typhimurium detection in food based on nano-self-assembly of alendronic acid modified upconversion and gold nanoparticles

2021 ◽  
Author(s):  
Min Chen ◽  
Leiqing Pan ◽  
K. Tu
Keyword(s):  
Gold Nanoparticles ◽  
Salmonella Typhimurium ◽  
Gold Nanoparticle ◽  
Alendronic Acid ◽  
Self Assembly ◽  
Upconversion Nanoparticles ◽  
Fluorescent Biosensor ◽  
Fluorescence Biosensor

A simple and quick responsive fluorescent biosensor for Salmonella typhimurium detection based on the recognition of aptamer coupled with alendronic acid (ADA)@upconversion nanoparticles (UCNPs) and gold nanoparticle (AuNPs) has been...

scholarly journals Enhanced Extracellular Synthesis of Gold Nanoparticles by Soluble Extracts from Escherichia coli Transformed with Rhizobium tropici Phytochelatin Synthase Gene

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 472
Author(s):  
Qunying Yuan ◽  
Manjula Bomma ◽  
Zhigang Xiao
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Synthesis Method ◽  
Nanoparticle Synthesis ◽  
Morphological Properties ◽  
Phytochelatin Synthase ◽  
Rhizobium Tropici ◽  
Whole Cells ◽  
E Coli ◽  
Recombinant Cells

Phytochelatins, the enzymatic products of phytochelatin synthase, play a principal role in protecting the plants from heavy metal and metalloid toxicity due to their ability to scavenge metal ions. In the present study, we investigated the capacity of soluble intracellular extracts from E. coli cells expressing R. tropici phytochelatin synthase to synthesize gold nanoparticle. We discovered that the reaction mediated by soluble extracts from the recombinant E. coli cells had a higher yield of gold nanoparticles, compared to that from the control cells. The compositional and morphological properties of the gold nanoparticles synthesized by the intracellular extracts from recombinant cells and control cells were similar. In addition, this extracellular nanoparticle synthesis method produced purer gold nanoparticles, avoiding the isolation of nanoparticles from cellular debris when whole cells are used to synthesize nanoparticles. Our results suggested that phytochelatins can improve the efficiency of gold nanoparticle synthesis mediated by bacterial soluble intracellular extracts, and the potential of extracellular nanoparticle synthesis platform for the production of nanoparticles in large quantity and pure form is worth further investigation.

scholarly journals Enhanced enzymatic activity from phosphotriesterase trimer gold nanoparticle bioconjugates for pesticide detection

The Analyst ◽  
2017 ◽  
Vol 142 (17) ◽  
pp. 3261-3271 ◽  
Author(s):  
John A. Hondred ◽  
Joyce C. Breger ◽  
Nate T. Garland ◽  
Eunkeu Oh ◽  
Kimihiro Susumu ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Enzymatic Activity ◽  
Gold Nanoparticle ◽  
Pesticide Detection

A significant enzymatic enhancement of phosphotriesterase has been demonstrated when immobilized on various sized gold nanoparticles.

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