scholarly journals Advances in the Application of Exosomes Identification Using Surface-Enhanced Raman Spectroscopy for the Early Detection of Cancers

Author(s):  
Lu Yang ◽  
Jingyuan Jia ◽  
Shenglong Li

Exosomes are small nanoscale vesicles with a double-layered lipid membrane structure secreted by cells, and almost all types of cells can secrete exosomes. Exosomes carry a variety of biologically active contents such as nucleic acids and proteins, and play an important role not only in intercellular information exchange and signal transduction, but also in various pathophysiological processes in the human body. Surface-enhanced Raman Spectroscopy (SERS) uses light to interact with nanostructured materials such as gold and silver to produce a strong surface plasmon resonance effect, which can significantly enhance the Raman signal of molecules adsorbed on the surface of nanostructures to obtain a rich fingerprint of the sample itself or Raman probe molecules with ultra-sensitivity. The unique advantages of SERS, such as non-invasive and high sensitivity, good selectivity, fast analysis speed, and low water interference, make it a promising technology for life science and clinical testing applications. In this paper, we briefly introduce exosomes and the current main detection methods. We also describe the basic principles of SERS and the progress of the application of unlabeled and labeled SERS in exosome detection. This paper also summarizes the value of SERS-based exosome assays for early tumor diagnosis.

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.


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.


Elements ◽  
2020 ◽  
Vol 16 (2) ◽  
pp. 117-122 ◽  
Author(s):  
Olivier Beyssac

This article reviews nonconventional Raman spectroscopy techniques and discusses present and future applications of these techniques in the Earth and planetary sciences. Time-resolved spectroscopy opens new ways to limit or exploit luminescence effects, whereas techniques based on coherent anti-Stokes Raman scattering (CARS) or surface-enhanced Raman spectroscopy (SERS) allow the Raman signal to be considerably enhanced even down to very high spatial resolutions. In addition, compact portable Raman spectrometers are now routinely used out of the laboratory and are even integrated to two rovers going to Mars in the near future.


1992 ◽  
Vol 46 (1) ◽  
pp. 147-151 ◽  
Author(s):  
Neil J. Pothier ◽  
R. Ken Forcé

An analytical application for Surface-Enhanced Raman Spectroscopy at a silver electrode is described. Real-time SER spectra of adenine and cytosine have been recorded in a 10-µL spectroelectrochemical flow cell under flowing conditions. Charge-coupled-device detection allowed high-quality spectra spanning a ∼1200 cm−1 region to be recorded with integration times of 4 seconds. A low-power He Ne laser was used as a source. SERS at the silver electrode offers rapid time response to adsorption/desorption by appropriate potential modulation. The technique is extremely reproducible and insensitive to temperature and flow rate. The effects of incident photon energy and applied potential on the intensity of the Raman signal are discussed.


2008 ◽  
Vol 62 (3) ◽  
pp. 267-272 ◽  
Author(s):  
J. Guicheteau ◽  
L. Argue ◽  
D. Emge ◽  
A. Hyre ◽  
M. Jacobson ◽  
...  

Surface-enhanced Raman spectroscopy (SERS) can provide rapid fingerprinting of biomaterial in a nondestructive manner. The adsorption of colloidal silver to biological material suppresses native biofluorescence while providing electromagnetic surface enhancement of the normal Raman signal. This work validates the applicability of qualitative SER spectroscopy for analysis of bacterial species by utilizing principal component analysis (PCA) to show discrimination of biological threat simulants, based upon multivariate statistical confidence limits bounding known data clusters. Gram-positive Bacillus spores ( Bacillus atrophaeus, Bacillus anthracis, and Bacillus thuringiensis) are investigated along with the Gram-negative bacterium Pantoea agglomerans.


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.


RSC Advances ◽  
2016 ◽  
Vol 6 (116) ◽  
pp. 115284-115289 ◽  
Author(s):  
Annette Dowd ◽  
Mathias Geisler ◽  
Shaoli Zhu ◽  
Michelle L. Wood ◽  
Michael B. Cortie

Large more reproducibly fabricated microstructures can also provide significant Raman signal enhancementviausually neglected multipolar plasmon resonances.


Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 24
Author(s):  
Affi Nur Hidayah ◽  
Djoko Triyono ◽  
Yuliati Herbani ◽  
Rosari Saleh

Deltamethrin pesticides can cause inflammation, nephrotoxicity and hepatotoxicity as well as affect the activity of antioxidant enzymes in tissues. As a result of this concern, there is a rising focus on the development of fast and reliable pesticide residue testing to minimise potential risks to humans. The goal of this study is to use Au-Ag colloid nanoparticles as liquid surface-enhanced Raman spectroscopy (SERS) to improve the Raman signal in the detection of deltamethrin pesticide in a brewed tea. The liquid SERS system is fascinating to study due to its ease of use and its unlikeliness to cause several phenomena, such as photo-bleaching, combustion, sublimation and even photo-catalysis, which can interfere with the Raman signal, as shown in the SERS substrate. Our liquid SERS system is simpler than previous liquid SERS systems that have been reported. We performed the detection of pesticide analyte directly on brewed tea, without diluting it with ethanol or centrifuging it. Femtosecond laser-induced photo-reduction was employed to synthesise the liquid SERS of Au, Au-Ag, and Ag colloidal nanoparticles. The SERS was utilised to detect deltamethrin pesticide in brewed tea. The result showed that liquid SERS-based Ag NPs significantly enhance the Raman signal of pesticides compared with liquid SERS-based Au NPs and Au-Ag Nanoalloys. The maximum residue limits (MRLs) in tea in Indonesia are set at 10 ppm. Therefore, this method was also utilised to detect and improve, to 0.01 ppm, the deltamethrin pesticide Limit of Detection (LOD).


Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4423 ◽  
Author(s):  
Edyta Pyrak ◽  
Jan Krajczewski ◽  
Artur Kowalik ◽  
Andrzej Kudelski ◽  
Aleksandra Jaworska

A sensitive and accurate identification of specific DNA fragments (usually containing a mutation) can influence clinical decisions. Standard methods routinely used for this type of detection are PCR (Polymerase Chain Reaction, and its modifications), and, less commonly, NGS (Next Generation Sequencing). However, these methods are quite complicated, requiring time-consuming, multi-stage sample preparation, and specially trained staff. Usually, it takes weeks for patients to obtain their results. Therefore, different DNA sensors are being intensively developed by many groups. One technique often used to obtain an analytical signal from DNA sensors is Raman spectroscopy. Its modification, surface-enhanced Raman spectroscopy (SERS), is especially useful for practical analytical applications due to its extra low limit of detection. SERS takes advantage of the strong increase in the efficiency of Raman signal generation caused by a local electric field enhancement near plasmonic (typically gold and silver) nanostructures. In this condensed review, we describe the most important types of SERS-based nanosensors for genetic studies and comment on their potential for becoming diagnostic tools.


Sign in / Sign up

Export Citation Format

Share Document