Impact of Surface Enhanced Raman Spectroscopy in Catalysis.

Catalysis stands as an indispensable cornerstone of modern society, underpinning the production of over 80% of manufactured goods and driving over 90% of industrial chemical processes. As the demand for more efficient and sustainable processes grows, better catalysts are needed. Understanding the working principles of catalysts is key, and over the last 50 years, surface-enhanced Raman Spectroscopy (SERS) has become essential.

Potential Alignment in Tandem Catalysts Enhances CO-to-CH Conversion Efficiencies.

The in-tandem catalyst holds great promise for addressing the limitation of low *CO coverage on Cu-based materials for selective CH generation during CO electroreduction. However, the potential mismatch between the CO-formation catalyst and the favorable C-C coupling Cu catalyst represents a bottleneck in these types of electrocatalysts, resulting in low tandem efficiencies. In this study, we propose a robust solution to this problem by introducing a wide-CO generation-potential window nickel single atom catalyst (Ni SAC) supported on a Cu catalyst.

Direct Bottom-Up Growth: A Paradigm Shift for Studies in Wet-Chemical Synthesis of Gold Nanoparticles.

Plasmonic gold nanoparticles have been used increasingly in solid-state systems because of their applicability in fabricating novel sensors, heterogeneous catalysts, metamaterials, and thermoplasmonic substrates. While bottom-up colloidal syntheses take advantage of the chemical environment to control size, shape, composition, surface chemistry, and crystallography of the nanostructures precisely, it can be challenging to assemble nanoparticles rationally from suspension onto solid supports or within devices. In this Review, we discuss a powerful recent synthetic methodology, bottom-up substrate growth, which circumvents time-consuming batch presynthesis, ligand exchange, and self-assembly steps by applying wet-chemical synthesis to form morphologically controlled nanostructures on supporting materials.

Atomically Local Electric Field Induced Interface Water Reorientation for Alkaline Hydrogen Evolution Reaction.

The slow water dissociation process in alkaline electrolyte severely limits the kinetics of HER. The orientation of H O is well known to affect the dissociation process, but H O orientation is hard to control because of its random distribution. Herein, an atomically asymmetric local electric field was designed by IrRu dizygotic single-atom sites (IrRu DSACs) to tune the H O adsorption configuration and orientation, thus optimizing its dissociation process.

Interface-Dependent Selectivity in Plasmon-Driven Chemical Reactions.

Plasmonic nanoparticles can drive chemical reactions powered by sunlight. These processes involve the excitation of surface plasmon resonances (SPR) and the subsequent charge transfer to adsorbed molecular orbitals. Nonetheless, controlling the flow of energy and charge from SPR to adsorbed molecules is still difficult to predict or tune.

Highly Selective Monomethylation of Amines with CO /H via Ag/Al O as a Catalyst.

The selective synthesis of monomethylated amines with CO is particularly challenging because the formation of tertiary amines is thermodynamically more favorable. Herein, a new strategy for the controllable synthesis of N-monomethylated amines from primary amines and CO /H is explored. First-principle calculations reveal that the dissociation of H via an heterolytic route reduces the reactivity of methylated amines and thus inhibit successive methylation.

Heteroatoms Induce Localization of the Electric Field and Promote a Wide Potential-Window Selectivity Towards CO in the CO Electroreduction.

Carbon dioxide electroreduction (CO RR) is a sustainable way of producing carbon-neutral fuels. Product selectivity in CO RR is regulated by the adsorption energy of reaction-intermediates. Here, we employ differential phase contrast-scanning transmission electron microscopy (DPC-STEM) to demonstrate that Sn heteroatoms on a Ag catalyst generate very strong and atomically localized electric fields.

Combined miRNA and SERS urine liquid biopsy for the point-of-care diagnosis and molecular stratification of bladder cancer.

Background: Bladder cancer (BC) has the highest per-patient cost of all cancer types. Hence, we aim to develop a non-invasive, point-of-care tool for the diagnostic and molecular stratification of patients with BC based on combined microRNAs (miRNAs) and surface-enhanced Raman spectroscopy (SERS) profiling of urine.

Methods: Next-generation sequencing of the whole miRNome and SERS profiling were performed on urine samples collected from 15 patients with BC and 16 control subjects (CTRLs).

SERS liquid biopsy in breast cancer. What can we learn from SERS on serum and urine?

SERS analysis of biofluids, coupled with classification algorithms, has recently emerged as a candidate for point-of-care medical diagnosis. Nonetheless, despite the impressive results reported in the literature, there are still gaps in our knowledge of the biochemical information provided by the SERS analysis of biofluids. Therefore, by a critical assignment of the SERS bands, our work aims to provide a systematic analysis of the molecular information that can be achieved from the SERS analysis of serum and urine obtained from breast cancer patients and controls.

SERS liquid biopsy: An emerging tool for medical diagnosis.

Surface-enhanced Raman scattering (SERS) is emerging as a novel strategy for biofluid analysis. In this review, we delineate four experimental SERS protocols that are frequently used for the profiling of biofluids: 1) liquid SERS for the detection of purine metabolites; 2) iodide-modified liquid SERS for the detection of proteins; 3) dried SERS for the detection of both purine metabolites and proteins; 4) resonant Raman for the detection of carotenoids. To explain the selectivity of each experimental SERS protocol, we introduce a heuristic model for the chemisorption of analytes mediated by adsorbed ions (adions) onto the SERS substrate.

SERS-Based Evaluation of the DNA Methylation Pattern Associated With Progression in Clonal Leukemogenesis of Down Syndrome.

Here we show that surface-enhanced Raman scattering (SERS) analysis captures the relative hypomethylation of DNA from patients with acute leukemia associated with Down syndrome (AL-DS) compared with patients diagnosed with transient leukemia associated with Down syndrome (TL-DS), an information inferred from the area under the SERS band at 1005 cm attributed to 5-methycytosine. The receiver operating characteristic (ROC) analysis of the area under the SERS band at 1005 cm yielded an area under the curve (AUC) of 0.77 in differentiating between the AL-DS and TL-DS groups.

Fermi Level Equilibration at the Metal-Molecule Interface in Plasmonic Systems.

We highlight a new metal-molecule charge transfer process by tuning the Fermi energy of plasmonic silver nanoparticles (AgNPs) . The strong adsorption of halide ions upshifts the Fermi level of AgNPs by up to ∼0.3 eV in the order Cl < Br < I, favoring the spontaneous charge transfer to aligned molecular acceptor orbitals until charge neutrality across the interface is achieved.

Recent advances in surface-enhanced Raman spectroscopy based liquid biopsy for colorectal cancer (Review).

As colorectal cancer (CRC) is one of the forms of cancer with the highest prevalence globally and with a high mortality, screening and early detection remains a major issue. Colonoscopy is still the gold standard for detecting premalignant lesions, but it is burdened by some complications. For instance, it is laborious, with some difficulties of acceptance for some patients, and is ultimately an imperfect standard, given that some premalignant lesions or incipient malignancies can be missed by colonoscopic evaluation.

Assessment of Gold-Coated Iron Oxide Nanoparticles as Negative T2 Contrast Agent in Small Animal MRI Studies.

Purpose: Magnetic resonance imaging (MRI) contrast agents are pharmaceuticals that enable a better visualization of internal body structures. In this study, we present the synthesis, MRI signal enhancement capabilities, in vitro as well as in vivo cytotoxicity results of gold-coated iron oxide nanoparticles (FeO@AuNPs) as potential contrast agents.

Methods: FeO@AuNPs were obtained by synthesizing iron oxide nanoparticles and gradually coating them with gold.

SERS-Based Assessment of MRD in Acute Promyelocytic Leukemia?

Acute promyelocytic leukemia (APL) is characterized by a unique chromosome translocation t(15;17)(q24;q21), which leads to the PML/RARA gene fusion formation. However, it is acknowledged that this rearrangement alone is not able to induce the whole leukemic phenotype. In addition, epigenetic processes, such as DNA methylation, may play a crucial role in leukemia pathogenesis.

Combining surface-enhanced Raman scattering (SERS) of saliva and two-dimensional shear wave elastography (2D-SWE) of the parotid glands in the diagnosis of Sjögren's syndrome.

In this study, we combine the molecular structural information gained by SERS of saliva samples with the morphological data given by two-dimensional shear wave elastography (2D-SWE) (SuperSonic Imagine, Aixplorer) of parotid glands in the case of n = 31 patients with Sjögren's syndrome (SjS) and n = 22 controls, with the aim to discriminate between the two groups. The overall classification accuracy yielded by a hybrid principal component analysis-linear discriminant analysis (PCA-LDA) model based on both SERS and elastography (81%) was superior to that yielded by SERS spectra alone (75%) and elastography data alone (71%). This preliminary study is the first report on the use of 2D-SWE of parotid glands for the diagnosis of SjS as well as the first to describe the diagnosis of SjS based on the SERS spectra of dried saliva samples, the results suggesting that the strategy of combining the two methods could improve the diagnosis of SjS.

SERS-Based Liquid Biopsy of Gastrointestinal Tumors Using a Portable Raman Device Operating in a Clinical Environment.

Early diagnosis based on screening is recognized as one of the most efficient ways of mitigating cancer-associated morbidity and mortality. Therefore, reliable but cost-effective methodologies are needed. By using a portable Raman spectrometer, a small and easily transportable instrument, the needs of modern diagnosis in terms of rapidity, ease of use and flexibility are met.

The role of Ag, Ca, Pb and Al adions in the SERS turn-on effect of anionic analytes.

In our recent studies we highlighted the role of adsorbed ions (adions) in turning on the surface-enhanced Raman scattering (SERS) effect in a specific mode for anionic and cationic analytes. In this work, we emphasize the role of Ag, Ca, Pb and Al adions in the specific adsorption of anionic analytes such as the citrate capping agent and three organic acids. Our results suggest an adion-specific adsorption mechanism: the adsorption of anionic analytes is facilitated by positively charged adions such as Ag, Ca, Pb or Al, which provide adsorption sites specific for the anionic analytes.

SERS assessment of the cancer-specific methylation pattern of genomic DNA: towards the detection of acute myeloid leukemia in patients undergoing hematopoietic stem cell transplantation.

In this label-free surface-enhanced Raman scattering (SERS) study of genomic DNA, we demonstrate that the cancer-specific DNA methylation pattern translates into specific spectral differences. Thus, DNA extracted from an acute myeloid leukemia (AML) cell line presented a decreased intensity of the 1005 cm band of 5-methylcytosine compared to normal DNA, in line with the well-described hypomethylation of cancer DNA. The unique methylation pattern of cancer DNA also influences the DNA adsorption geometry, resulting in higher adenine SERS intensities for cancer DNA.

SERS-based differential diagnosis between multiple solid malignancies: breast, colorectal, lung, ovarian and oral cancer.

Purpose: Surface-enhanced Raman scattering (SERS) spectroscopy on serum and other biofluids for cancer diagnosis represents an emerging field, which has shown promising preliminary results in several types of malignancies. The purpose of this study was to demonstrate that SERS spectroscopy on serum can be employed for the differential diagnosis between five of the leading malignancies, ie, breast, colorectal, lung, ovarian and oral cancer.

Patients And Methods: Serum samples were acquired from healthy volunteers (n=39) and from patients diagnosed with breast (n=42), colorectal (n=109), lung (n=33), oral (n=17), and ovarian cancer (n=13), comprising n=253 samples in total.