Surface-Enhanced Raman Signal for Terbium Single-Molecule Magnets Grafted on Graphene

ACS Nano ◽  
2010 ◽  
Vol 4 (12) ◽  
pp. 7531-7537 ◽  
Author(s):  
Manuel Lopes ◽  
Andrea Candini ◽  
Matias Urdampilleta ◽  
Antoine Reserbat-Plantey ◽  
Valerio Bellini ◽  
...  
2004 ◽  
Vol 18 (3) ◽  
pp. 433-440 ◽  
Author(s):  
Katrin Kneipp ◽  
Harald Kneipp ◽  
Salim Abdali ◽  
Rolf W. Berg ◽  
Henrik Bohr

Enkephalin, an endogeneous substance in the human brain showing morphine‒like biological functions, has been detected at the single molecule level based on the surface‒enhanced Raman signal of the ring breathing mode of phenylalanine, which is one building block of the molecule. For enhancing the Raman signal the enkephalin molecules have been attached to silver colloidal cluster structures. The experiments demonstrate that the SERS signal of the strongly enhanced ring breathing vibration of phenylalanine at 1000 cm−1can be used as “intrinsic marker” for detecting a single enkephalin molecule without using a specific label molecule. The reported result suggests the use of the phenylalanine 1000 cm−1SERS line as spectroscopic signature for monitoring single proteins containing this amino acid as a building block.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Simon D. Dryden ◽  
Salzitsa Anastasova ◽  
Giovanni Satta ◽  
Alex J. Thompson ◽  
Daniel R. Leff ◽  
...  

AbstractUrinary tract infection is one of the most common bacterial infections leading to increased morbidity, mortality and societal costs. Current diagnostics exacerbate this problem due to an inability to provide timely pathogen identification. Surface enhanced Raman spectroscopy (SERS) has the potential to overcome these issues by providing immediate bacterial classification. To date, achieving accurate classification has required technically complicated processes to capture pathogens, which has precluded the integration of SERS into rapid diagnostics. This work demonstrates that gold-coated membrane filters capture and aggregate bacteria, separating them from urine, while also providing Raman signal enhancement. An optimal gold coating thickness of 50 nm was demonstrated, and the diagnostic performance of the SERS-active filters was assessed using phantom urine infection samples at clinically relevant concentrations (105 CFU/ml). Infected and uninfected (control) samples were identified with an accuracy of 91.1%. Amongst infected samples only, classification of three bacteria (Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae) was achieved at a rate of 91.6%.


Author(s):  
Arpan Dutta ◽  
Tarmo Nuutinen ◽  
Khairul Alam ◽  
Antti Matikainen ◽  
Peng Li ◽  
...  

Abstract Plasmonic nanostructures are widely utilized in surface-enhanced Raman spectroscopy (SERS) from ultraviolet to near-infrared applications. Periodic nanoplasmonic systems such as plasmonic gratings are of great interest as SERS-active substrates due to their strong polarization dependence and ease of fabrication. In this work, we modelled a silver grating that manifests a subradiant plasmonic resonance as a dip in its reflectivity with significant near-field enhancement only for transverse-magnetic (TM) polarization of light. We investigated the role of its fill factor, commonly defined as a ratio between the width of the grating groove and the grating period, on the SERS enhancement. We designed multiple gratings having different fill factors using finite-difference time-domain (FDTD) simulations to incorporate different degrees of spectral detunings in their reflection dips from our Raman excitation (488 nm). Our numerical studies suggested that by tuning the spectral position of the optical resonance of the grating, via modifying their fill factor, we could optimize the achievable SERS enhancement. Moreover, by changing the polarization of the excitation light from transverse-magnetic to transverse-electric, we can disable the optical resonance of the gratings resulting in negligible SERS performance. To verify this, we fabricated and optically characterized the modelled gratings and ensured the presence of the desired detunings in their optical responses. Our Raman analysis on riboflavin confirmed that the higher overlap between the grating resonance and the intended Raman excitation yields stronger Raman enhancement only for TM polarized light. Our findings provide insight on the development of fabrication-friendly plasmonic gratings for optimal intensification of the Raman signal with an extra degree of control through the polarization of the excitation light. This feature enables studying Raman signal of exactly the same molecules with and without electromagnetic SERS enhancements, just by changing the polarization of the excitation, and thereby permits detailed studies on the selection rules and the chemical enhancements possibly involved in SERS.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Li Yuan ◽  
Jinghuai Fang ◽  
Yonglong Jin ◽  
Chaonan Wang ◽  
Tian Xu

We fabricated a simple, cheap, and functional surface enhanced Raman scattering substrate for biomedical application. Hot spots between two close silver nanoparticles distributed in the skeleton of a three-dimensional porous membrane, especially in the pores, were formed. The dual poles of micropores in the membrane were discussed. The pores could protect the silver nanoparticles in the pores from being oxidized, which makes the membrane effective for a longer period of time. In addition,Staphylococcus aureuscells could be trapped by the micropores and then the Raman signal became stronger, indicating that the functional surface enhanced Raman scattering substrate is reliable.


Biosensors ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 449
Author(s):  
Francesco Dell’Olio

The recent improvements in diagnosis enabled by advances in liquid biopsy and oncological imaging significantly better cancer care. Both these complementary approaches, which are used for early tumor detection, characterization, and monitoring, can benefit from applying techniques based on surface-enhanced Raman scattering (SERS). With a detection sensitivity at the single-molecule level, SERS spectroscopy is widely used in cell and molecular biology, and its capability for the in vitro detection of several types of cancer biomarkers is well established. In the last few years, several intriguing SERS applications have emerged, including in vivo imaging for tumor targeting and the monitoring of drug release. In this paper, selected recent developments and trends in SERS applications in the field of liquid biopsy and tumor imaging are critically reviewed, with a special emphasis on results that demonstrate the clinical utility of SERS.


2004 ◽  
Author(s):  
Martin Moskovits ◽  
Dae-Hong Jeong ◽  
Tsachi Livneh ◽  
Yiying Wu ◽  
Galen D. Stucky

2004 ◽  
Vol 818 ◽  
Author(s):  
Vitaliy N. Pustovit ◽  
Tigran V. Shahbazyan

AbstractWe study the role of a strong electron confinement on the surface-enhanced Raman scattering from molecules adsorbed on small noble-metal nanoparticles. We describe a novel enhancement mechanism which originates from the different effect that confining potential has on s-band and d-band electrons. We demonstrate that the interplay between finite-size and screening efects in the nanoparticle surface layer leads to an enhancement of the surface plasmon local field acting on a molecule located in a close proximity to the metal surface. Our calculations show that the additional enhancement of the Raman signal is especially strong for small nanometer-sized nanoparticles.


Sign in / Sign up

Export Citation Format

Share Document