scholarly journals Assessing Plasmonic Nanoprobes in Electromagnetic Field Enhancement for SERS Detection of Biomarkers

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8345
Author(s):  
Han-Wen Cheng ◽  
Shu-Yan Xue ◽  
Jing Li ◽  
Justine S. Gordon ◽  
Shan Wang ◽  
...  

The exploration of the plasmonic field enhancement of nanoprobes consisting of gold and magnetic core@gold shell nanoparticles has found increasing application for the development of surface-enhanced Raman spectroscopy (SERS)-based biosensors. The understanding of factors controlling the electromagnetic field enhancement, as a result of the plasmonic field enhancement of the nanoprobes in SERS biosensing applications, is critical for the design and preparation of the optimal nanoprobes. This report describes findings from theoretical calculations of the electromagnetic field intensity of dimer models of gold and magnetic core@gold shell nanoparticles in immunoassay SERS detection of biomarkers. The electromagnetic field intensities for a series of dimeric nanoprobes with antibody–antigen–antibody binding defined interparticle distances were examined in terms of nanoparticle sizes, core–shell sizes, and interparticle spacing. The results reveal that the electromagnetic field enhancement not only depended on the nanoparticle size and the relative core size and shell thicknesses of the magnetic core@shell nanoparticles but also strongly on the interparticle spacing. Some of the dependencies are also compared with experimental data from SERS detection of selected cancer biomarkers, showing good agreement. The findings have implications for the design and optimization of functional nanoprobes for SERS-based biosensors.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
H. Rajabi-Moghaddam ◽  
M. R. Naimi-Jamal ◽  
M. Tajbakhsh

AbstractIn the present work, an attempt has been made to synthesize the 1,2,3-triazole derivatives resulting from the click reaction, in a mild and green environment using the new copper(II)-coated magnetic core–shell nanoparticles Fe3O4@SiO2 modified by isatoic anhydride. The structure of the catalyst has been determined by XRD, FE-SEM, TGA, VSM, EDS, and FT-IR analyzes. The high efficiency and the ability to be recovered and reused for at least up to 6 consecutive runs are some superior properties of the catalyst.


Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 688 ◽  
Author(s):  
Asli Yilmaz ◽  
Mehmet Yilmaz

Despite numerous attempts to fabricate the core–shell nanoparticles, novel, simple, and low-cost approaches are still required to produce these efficient nanosystems. In this study, we propose the synthesis of bimetallic core–shell nanoparticles of gold (AuNP) and silver (AgNP) nanostructures via a bioinspired polydopamine (PDOP) layer and their employment as a surface-enhanced Raman spectroscopy (SERS) platform. Herein, the PDOP layer was used as an interface between nanostructures as well as stabilizing and reducing agents for the deposition of silver ions onto the AuNPs. UV-vis absorption spectra and electron microscope images confirmed the deposition of the silver ions and the formation of core–shell nanoparticles. SERS activity tests indicated that both the PDOP thickness and silver deposition time are the dominant parameters that determine the SERS performances of the proposed core–shell system. In comparison to bare AuNPs, more than three times higher SERS signal intensity was obtained with an enhancement factor of 3.5 × 105.


BIOspektrum ◽  
2021 ◽  
Vol 27 (4) ◽  
pp. 442-444
Author(s):  
Frank Mickoleit ◽  
Sabine Rosenfeldt ◽  
Anna S. Schenk ◽  
Dirk Schüler ◽  
René Uebe

AbstractBacterial magnetosomes represent magnetic core-shell nanoparticles biomineralized by magnetotactic bacteria like Magnetospirillum gryphiswaldense. The establishment of fermentation regimes for high-yield particle production, standardized isolation procedures as well as the development of a genetic toolkit for the generation of “tailored” particles might soon pave the way for the application of engineered magnetosomes in the biomedical and biotechnological field.


2019 ◽  
Vol 223 ◽  
pp. 68-74 ◽  
Author(s):  
Angela M. Gutierrez ◽  
Rohit Bhandari ◽  
Jiaying Weng ◽  
Arnold Stromberg ◽  
Thomas D. Dziubla ◽  
...  

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