Fundamentals and applications of SERS-based bioanalytical sensing

Abstract

Abstract:Plasmonics is an emerging field that examines the interaction between light and metallic nanostructures at the metal-dielectric interface. Surface-enhanced Raman scattering (SERS) is a powerful analytical technique that uses plasmonics to obtain detailed chemical information of molecules or molecular assemblies adsorbed or attached to nanostructured metallic surfaces. For bioanalytical applications, these surfaces are engineered to optimize for high enhancement factors and molecular specificity. In this review we focus on the fabrication of SERS substrates and their use for bioanalytical applications. We review the fundamental mechanisms of SERS and parameters governing SERS enhancement. We also discuss developments in the field of novel SERS substrates. This includes the use of different materials, sizes, shapes, and architectures to achieve high sensitivity and specificity as well as tunability or flexibility. Different fundamental approaches are discussed, such as label-free and functional assays. In addition, we highlight recent relevant advances for bioanalytical SERS applied to small molecules, proteins, DNA, and biologically relevant nanoparticles. Subsequently, we discuss the importance of data analysis and signal detection schemes to achieve smaller instruments with low cost for SERS-based point-of-care technology developments. Finally, we review the main advantages and challenges of SERS-based biosensing and provide a brief outlook.

Raman and Surface-Enhanced Raman Scattering for Biofilm Characterization

“…As a result, the sensitivity in SERS is significantly increased and the detection limit is lowered. For more information on the biological applications of SERS other than in biofilms, we refer the readers to review articles published recently [24,25]. Although the enhancement in scattering makes SERS suitable for many applications in several fields, there are still some challenges preventing the implementation of this technique widely including clinical applications.…”

Are plasmonic optical biosensors ready for use in point-of-need applications?

“…Compared to gold, silver has larger plasmonic tunable range throughout the visible range and extends in the UV range down to 350 nm. 13,47 The range can be further extended in the UV by using aluminum, which allows plasmonic resonances down to approximately 200 nm. 47 Considering the drawbacks of metals, researchers are also searching for other materials as the substitute of metals.…”

“…Plasmonics combines techniques from photonics and electronics at the nanoscale to perform optical measurements of spectra and refractive index changes (via reflection angles) that are related to the chemical structure, or binding events, and can help extract valuable information about the presence, concentration, or identity of molecules of interest. 13,14 The study of plasmonics relies on localized or propagating surface plasmons (SPs), which are collective (coherent) oscillations of electrons in the metal, and are generated by the coupling of the incident oscillating electric field of the electromagnetic wave with the electrons at the metal-dielectric interface. 15 The optical response of plasmonic materials can be described via the dielectric function (or complex permittivity), ε(ω), where ω is the angular frequency of the light.…”

Exosomes: Isolation, Analysis, and Applications in Cancer Detection and Therapy

“…In addition, SERS is also an effective technique for quantitative analysis of biological small molecules. Raman scattering signals arise from the adsorption between molecules and the surfaces of metallic nanostructures, and the signals can be enhanced by a local electromagnetic field . Zong et al.…”