Nanoparticle-based Surface-enhanced Raman Scattering Research Articles

A Review of Magnetic Nanoparticle-Based Surface-Enhanced Raman Scattering Substrates for Bioanalysis: Morphology, Function and Detection Application.

Surface-enhanced Raman scattering (SERS) is a kind of popular non-destructive and water-free interference analytical technology with fast response, excellent sensitivity and specificity to trace biotargets in biological samples. Recently, many researches have focused on the preparation of various magnetic nanoparticle-based SERS substrates for developing efficient bioanalytical methods, which greatly improved the selectivity and accuracy of the proposed SERS bioassays. There has been a rapid increase in the number of reports about magnetic SERS substrates in the past decade, and the number of related papers and citations have exceeded 500 and 2000, respectively. Moreover, most of the papers published since 2009 have been dedicated to analytical applications. In the paper, the recent advances in magnetic nanoparticle-based SERS substrates for bioanalysis were reviewed in detail based on their various morphologies, such as magnetic core-shell nanoparticles, magnetic core-satellite nanoparticles and non-spherical magnetic nanoparticles and their different functions, such as separation and enrichment, recognition and SERS tags. Moreover, the typical application progress on magnetic nanoparticle-based SERS substrates for bioanalysis of amino acids and protein, DNA and RNA sequences, cancer cells and related tumor biomarkers, etc., was summarized and introduced. Finally, the future trends and prospective for SERS bioanalysis by magnetic nanoparticle-based substrates were proposed based on the systematical study of typical and latest references. It is expected that this review would provide useful information and clues for the researchers with interest in SERS bioanalysis.

Toward Quantitative Surface-Enhanced Raman Scattering with Plasmonic Nanoparticles: Multiscale View on Heterogeneities in Particle Morphology, Surface Modification, Interface, and Analytical Protocols.

Surface-enhanced Raman scattering (SERS) provides significantly enhanced Raman scattering signals from molecules adsorbed on plasmonic nanostructures, as well as the molecules' vibrational fingerprints. Plasmonic nanoparticle systems are particularly powerful for SERS substrates as they provide a wide range of structural features and plasmonic couplings to boost the enhancement, often up to >108-1010. Nevertheless, nanoparticle-based SERS is not widely utilized as a means for reliable quantitative measurement of molecules largely due to limited controllability, uniformity, and scalability of plasmonic nanoparticles, poor molecular modification chemistry, and a lack of widely used analytical protocols for SERS. Furthermore, multiscale issues with plasmonic nanoparticle systems that range from atomic and molecular scales to assembled nanostructure scale are difficult to simultaneously control, analyze, and address. In this perspective, we introduce and discuss the design principles and key issues in preparing SERS nanoparticle substrates and the recent studies on the uniform and controllable synthesis and newly emerging machine learning-based analysis of plasmonic nanoparticle systems for quantitative SERS. Specifically, the multiscale point of view with plasmonic nanoparticle systems toward quantitative SERS is provided throughout this perspective. Furthermore, issues with correctly estimating and comparing SERS enhancement factors are discussed, and newly emerging statistical and artificial intelligence approaches for analyzing complex SERS systems are introduced and scrutinized to address challenges that cannot be fully resolved through synthetic improvements.

Surface-Imprinted Gold Nanoparticle-Based Surface-Enhanced Raman Scattering for Sensitive and Specific Detection of Patulin in Food Samples

As patulin is a kind of mycotoxin commonly found in fruit products, it is of great importance to develop simple and accurate analytical methods for the sensitive detection of patulin (PAT). In this work, based on molecular imprinted polymer (MIP) and surface-enhanced Raman scattering (SERS) technique, a specific and sensitive PAT sensor was developed. To prepare the MIP-SERS sensor, gold nanoparticles (Au NPs) were synthesized to act as supported substrate, 4-vinylpyridine (4-VP) served as functional monomer, 1,4-diacryloylpiperazine (PDA) served as cross-linker, PAT served as template molecule, and horseradish peroxidase (HRP) served as initiator. Owing to the good SERS character of Au NPs and excellent selectivity of MIP, the MIP-SERS sensor had a superior performance in PAT detection. Under the optimized conditions, this sensor exhibited a good linearity (R2 = 0.9877) with a range from 7.00 × 10−12 to 5.00 × 10−8 M for PAT. By simply incubating analytes with MIP-SERS substrate, the proposed method showed an enhanced SERS signal with a limit of detection of 5.37 × 10−12 M (S/N = 3). Besides, in the presence of interferences such as 2-oxindole (OXD) and 5-hydroxymethylfurfural (5-HMF), the MIP-SERS substrate showed good selectivity for PAT. What is more, the method had acceptable precision with recoveries of 96~108% in fruit product inspection, revealing its potential application in food analysis and safety verification.

Ultrasensitive Analyte Detection by Combining Nanoparticle-based Surface-Enhanced Raman Scattering (SERS) Substrates with Multivariate Analysis

A facile and rapid method for the in situ fabrication of highly active surface-enhanced Raman scattering (SERS) substrates is presented. These SERS-active substrates are produced on the surface of microelectrode chips through an electric field-guided assembly of silver nanocolloids, which yields highly branched, dendritic nanoparticle structures. Fractal dimension analysis of the dendrites shows a value of 1.78, indicating a high degree of complexity. The sensitivity of the SERS substrates is demonstrated with the detection of trace amounts of cocaine in water. By analyzing the collected spectra using principal component analysis, spectra can be correctly identified and quantified in an automated fashion for several different concentrations

Application of silver nanoparticle‐based SERS spectroscopy for DNA analysis in radiated nasopharyngeal carcinoma cells

This work aims to explore the application of silver nanoparticle‐based surface‐enhanced Raman scattering (SERS) for nasopharyngeal carcinoma cell line CNE2's DNA analysis after X‐ray radiation. The cells are separated into control group and radiated groups with different dose of 6, 10, 15 and 20 Gy. The results show that after radiation (6, 10, 15 and 20 Gy), the DNA of radiated CNE2 have changed after 72 h of cell incubation. Principal components analysis is employed for significant differences and the DNA extracted after 72 h of incubation show significant divisions from control group. Moreover, a classifier based on support vector machines shows high classification accuracy between DNA extracted after 72 h of incubation and control group. In conclusion, this study first reveals SERS characteristics of CNE2's DNA under different dose of X‐ray radiation, and the final results may do favor to make known the mechanism of X‐ray radiation interacting with tumor. Copyright © 2013 John Wiley & Sons, Ltd.

Gold Nanoparticle-Based Surface-Enhanced Raman Scattering for Noninvasive Molecular Probing of Embryonic Stem Cell Differentiation

This study reports the use of gold nanoparticle-based surface-enhanced Raman scattering (SERS) for probing the differentiation of mouse embryonic stem (mES) cells, including undifferentiated single cells, embryoid bodies (EBs), and terminally differentiated cardiomyocytes. Gold nanoparticles (GNPs) were successfully delivered into all 3 mES cell differentiation stages without affecting cell viability or proliferation. Transmission electron microscopy (TEM) confirmed the localization of GNPs inside the following cell organelles: mitochondria, secondary lysosome, and endoplasmic reticulum. Using bright- and dark-field imaging, the bright scattering of GNPs and nanoaggregates in all 3 ES cell differentiation stages could be visualized. EB (an early differentiation stage) and terminally differentiated cardiomyocytes both showed SERS peaks specific to metabolic activity in the mitochondria and to protein translation (amide I, amide II, and amide III peaks). These peaks have been rarely identified in undifferentiated single ES cells. Spatiotemporal changes observed in the SERS spectra from terminally differentiated cardiomyocyte tissues revealed local and dynamic molecular interactions as well as transformations during ES cell differentiation.

Gold Nanoparticle-based Surface Enhanced Raman Scattering Spectroscopic Assay for the Detection of Protein–Protein Interactions

In the present work, a sensitive spectroscopic assay based on surface-enhanced Raman spectroscopy (SERS) using gold nanoparticles as substrates was developed for the rapid detection protein-protein interactions. Detection is achieved by specific binding biotin-modification antibodies with protein-stabilized 30 nm gold nanoparticles, followed by the attachment of avidin-modification Raman-active dyes. As a proof-of-principle experiment, a well-known biomolecular recognition system, IgG with protein A, was chosen to establish this new spectroscopic assay. Highly selective recognition of IgG down to 1 ng/ml in solution has been demonstrated.