scholarly journals Sunflower-Like Nanostructure with Built-In Hotspots for Alpha-Fetoprotein Detection

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1197
Author(s):  
Xiaoyu Zhao ◽  
Aonan Zhu ◽  
Yaxin Wang ◽  
Yongjun Zhang ◽  
Xiaolong Zhang

In the present study, a sunflower-like nanostructure array composed of a series of synaptic nanoparticles and nanospheres was manufactured through an efficient and low-cost colloidal lithography technique. The primary electromagnetic field contribution generated by the synaptic nanoparticles of the surface array structures was also determined by a finite-difference time-domain software to simulate the hotspots. This structure exhibited high repeatability and excellent sensitivity; hence, it was used as a surface-enhanced Raman spectroscopy (SERS) active substrate to achieve a rapid detection of ultra-low concentrations of Alpha-fetoprotein (AFP). This study demonstrates the design of a plasmonic structure with strong electromagnetic coupling, which can be used for the rapid detection of AFP concentration in clinical medicine.

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.


2006 ◽  
Vol 951 ◽  
Author(s):  
Motofumi Suzuki ◽  
Kaoru Nakajima ◽  
Kenji Kimura ◽  
Takao Fukuoka ◽  
Yasushige Mori

ABSTRACTWe have demonstrated surface-enhanced Raman spectroscopy on arrays of Au nanorods aligned in line by a dynamic oblique deposition technique. For the light polarized along the major axis of the nanorods, the plasma resonance of the Au nanorods has been tuned to a wavelength suitable for Raman spectroscopy. The Raman scattering on the discrete nanorods is enhanced significantly compared with that on semi continuous Au films. Since the preparation process is physically bottom-up, it is robust in its selection of the materials and is useful in providing the SERS sensors at low cost.


2016 ◽  
Vol 8 (7) ◽  
pp. 1602-1608 ◽  
Author(s):  
Shintaro Pang ◽  
Lili He

Aptamer–gold nanoparticle (AuNP) based colorimetric assays have become increasingly popular as viable rapid detection methods, but the molecular interactions governing the mechanism and successful interpretation of color changes have not been explored well.


2021 ◽  
Author(s):  
revathy m s ◽  
D Murugesan ◽  
Naidu Dhanpal Jayram

Abstract Thin films and Surface Enhanced Raman spectroscopy have a strong bonding towards development of Sensors. From last 4 decades SERS has been used as effective tool for detection of toxic dyes, in food industry and agriculture world. To minimize the cost and fabrication over large surface is the most challenging task in substrate fabrication. In the present work an attempt has been made towards dual coatings, which could act as an effective SERS Substrates. An effective and facile approach of low cost bi-metallic Nanostructured film has been fabricated using thermal evaporation. Using the standard characterization techniques such as FE-SEM and XRD, the obtained films were Rhodamine 6G was used as an analyte for the SERS studies. The detection of R6G was up to 10− 10mol l− 1solution.The present bi-metallic coating can be serves as an excellent SERS active surface and provides a versatile pathway to fabricate anisotropic nanostructure on a glass film.


2021 ◽  
Vol 11 (17) ◽  
pp. 8067
Author(s):  
Zixun Jia ◽  
Sarah Asiri ◽  
Asma Elsharif ◽  
Widyan Alamoudi ◽  
Ebtesam Al-Suhaimi ◽  
...  

Rapid detection of bacteria is a very critical and important part of infectious disease treatment. Sepsis kills more than 25 percent of its victims, resulting in as many as half of all deaths in hospitals before identifying the pathogen for patients to get the right treatment. Raman spectroscopy is a promising candidate in pathogen diagnosis given its fast and label-free nature, only if the concentration of the pathogen is high enough to provide reasonable sensitivity. This work reports a new design of surface-enhanced Raman spectroscopy (SERS) substrate which will provide high enough sensitivity and fast and close contact of the target structure to the optical hot spots for immunomagnetic capturing-based bacteria-concentrating technique. The substrate uses inverted nanocone structure arrays made of transparent PDMS (Polydimethylsiloxane) to funnel the light from the bottom to the top of the cones where plasmonic gold nanorods are located. A high reflective and low loss layer is deposited on the outer surface of the cone. Given the geometry of cones, photons are multi-reflected by the outer layer and thus the number density of photons at hotspots increases by an order of magnitude, which could be high enough to detect immunomagnetically densified bacteria.


2020 ◽  
Vol 6 (5) ◽  
pp. 947-953 ◽  
Author(s):  
Yen Lynn Wong ◽  
Wei Cherng Malvin Kang ◽  
Miguel Reyes ◽  
Jeanette Woon Pei Teo ◽  
James Chen Yong Kah

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