Self-assembled PVP-gold nanostar films as plasmonic substrates for surface-enhanced spectroscopies: influence of the polymeric coating on the enhancement efficiency.

Colloidal nanoparticles exhibiting anisotropic morphologies are preferred in the structural design of spectroscopically active substrates due to the remarkable optical properties of this type of nano-object. In the particular case of star-like nanoparticles, their sharp tips can act as antennae for capturing and amplifying the incident light, as well as for enhancing the light emitted by nearby fluorophores or the scattering efficiency of Raman active molecules. In the current work, we aimed to implement such star-shaped nanoparticles in the fabrication of nanoparticle films and explore their use as solid plasmonic substrates for surface-enhanced optical spectroscopies.

Toward microfluidic SERS and EC-SERS applications via tunable gold films over nanospheres.

Many promising applications of surface-enhanced Raman scattering (SERS), such as microfluidic SERS and electrochemical (EC)-SERS, require immersion of plasmonic nanostructured films in aqueous media. Correlational investigations of the optical response and SERS efficiency of solid SERS substrates immersed in water are absent in the literature. This work presents an approach for tuning the efficiency of gold films over nanospheres (AuFoN) as SERS substrates for applications in aqueous environment.

A New Detection Method of Oral and Oropharyngeal Squamous Cell Carcinoma Based on Multivariate Analysis of Surface Enhanced Raman Spectra of Salivary Exosomes.

Raman spectroscopy recently proved a tremendous capacity to identify disease-specific markers in various (bio)samples being a non-invasive, rapid, and reliable method for cancer detection. In this study, we first aimed to record vibrational spectra of salivary exosomes isolated from oral and oropharyngeal squamous cell carcinoma patients and healthy controls using surface enhancement Raman spectroscopy (SERS). Then, we assessed this method's capacity to discriminate between malignant and non-malignant samples by means of principal component-linear discriminant analysis (PC-LDA) and we used area under the receiver operating characteristics with illustration as the area under the curve to measure the power of salivary exosomes SERS spectra analysis to identify cancer presence.

Gold vs. Silver Colloidal Nanoparticle Films for Optimized SERS Detection of Propranolol and Electrochemical-SERS Analyses.

The increasing pollution of surface and groundwater bodies by pharmaceuticals is a general environmental problem requiring routine monitoring. Conventional analytical techniques used to quantify traces of pharmaceuticals are relatively expensive and generally demand long analysis times, associated with difficulties in performing field analyses. Propranolol, a widely used β-blocker, is representative of an emerging class of pharmaceutical pollutants with a noticeable presence in the aquatic environment.

A simple approach for coffee-ring suppression yielding homogeneous drying patterns of ZnO and TiO nanoparticles.

Evaporation-induced self-assembly in colloidal droplets is a method for organising nanoparticles on substrates, with various resulting patterns. The coffee-ring pattern is among the most common ones, but its non-uniformity limits its applicability, which led to efforts for developing coffee-ring suppression strategies. Considering the wide applicability of ZnO and TiO nanoparticles, there is a high demand for practical means to deposit them as uniform films.