ZnO–Ag hybrids for ultrasensitive detection of trinitrotoluene by surface-enhanced Raman spectroscopy

2014 ◽  
Vol 16 (28) ◽  
pp. 14706-14712 ◽  
Author(s):  
Xuan He ◽  
Hui Wang ◽  
Zhongbo Li ◽  
Dong Chen ◽  
Qi Zhang

Low-cost SERS sensors were fabricated by 4-ATP-functionalized ZnO–Ag hybrid substrates for TNT detection with high sensitivity, selectivity and reproducibility.

Biosensors ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 477
Author(s):  
Samar Ali Ghopry ◽  
Seyed M. Sadeghi ◽  
Cindy L. Berrie ◽  
Judy Z. Wu

Nanohybrids of graphene and two-dimensional (2D) layered transition metal dichalcogenides (TMD) nanostructures can provide a promising substrate for extraordinary surface-enhanced Raman spectroscopy (SERS) due to the combined electromagnetic enhancement on TMD nanostructures via localized surface plasmonic resonance (LSPR) and chemical enhancement on graphene. In these nanohybrid SERS substrates, the LSPR on TMD nanostructures is affected by the TMD morphology. Herein, we report the first successful growth of MoS2 nanodonuts (N-donuts) on graphene using a vapor transport process on graphene. Using Rhodamine 6G (R6G) as a probe, SERS spectra were compared on MoS2 N-donuts/graphene nanohybrids substrates. A remarkably high R6G SERS sensitivity up to 2 × 10−12 M has been obtained, which can be attributed to the more robust LSPR effect than in other TMD nanostructures such as nanodiscs as suggested by the finite-difference time-domain simulation. This result demonstrates that non-metallic TMD/graphene nanohybrids substrates can have SERS sensitivity up to one order of magnitude higher than that reported on the plasmonic metal nanostructures/2D materials SERS substrates, providing a promising scheme for high-sensitivity, low-cost applications for biosensing.


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.


Author(s):  
Nancy Ornelas-Soto ◽  
Iris A. Aguilar-Hernández ◽  
Nils Kristian Afseth ◽  
Tzarara López-Luke ◽  
Flavio Contreras-Torres ◽  
...  

Author(s):  
Anil K. Kodali ◽  
Rohit Bhargava

This article describes the use of nanostructured probes to enhance optical and vibrational spectroscopic imaging for biomedical applications. Engineered probes and surfaces are promising tools for enhancing signals for ultrasensitive detection of diseases like carcinoma. Two methods of interest are surface-enhanced infrared absorption (SEIRA) spectroscopy and surface-enhanced Raman spectroscopy (SERS) for IR and Raman modalities, respectively. SERS and SEIRA can be broadly categorized under a common modality termed surface-enhanced vibrational spectroscopy. This article first reviews various breakthrough findings reported in SERS and SEIRA, along with different types ofsubstrates and contrast agents used in realizing the enhancement and theories proposed to explain these findings. It then considers the configurations of nano-LAMPs and presents example results demonstrating their optical resonances and tunability. Finally, it evaluates a few techniques for fabricating multilayered nanoparticles and highlights some issues with respect to fabrication.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Angela Capaccio ◽  
Antonio Sasso ◽  
Giulia Rusciano

AbstractThe fabrication of plasmonic nanostructures with a reliable, low cost and easy approach has become a crucial and urgent challenge in many fields, including surface-enhanced Raman spectroscopy (SERS) based applications. In this frame, nanoporous metal films are quite attractive, due to their intrinsic large surface area and high density of metal nanogaps, acting as hot-spots for Raman signal enhancement. In this paper, we report a detailed study on the fabrication of nanoporous silver-based SERS substrates, obtained by the application of two successive treatments with an Inductively Coupled Plasma (ICP) system, using synthetic air and Ar as feeding gases. The obtained substrates exhibit a quite broad plasmonic response, covering the Vis–NIR range, and an enhancement factor reaching 6.5 $$\times\, 10^7$$ × 10 7 , estimated by using 4-mercaptobenzoic acid (4-MBA) as probe molecule at 532 nm. Moreover, the substrates exhibit a quite good spatial reproducibility on a centimeter scale, which assures a good signal stability for analytical measurements. Globally, the developed protocol is easy and cost effective, potentially usable also for mass production thanks to the remarkable inter-batches reproducibility. As such, it holds promise for its use in SERS-based sensing platforms for sensitive detection of targets molecules.


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