Noble Metal-Assisted Surface Plasmon Resonance Immunosensors

Abstract

For the early diagnosis of several diseases, various biomarkers have been discovered and utilized through the measurement of concentrations in body fluids such as blood, urine, and saliva. The most representative analytical method for biomarker detection is an immunosensor, which exploits the specific antigen-antibody immunoreaction. Among diverse analytical methods, surface plasmon resonance (SPR)-based immunosensors are emerging as a potential detection platform due to high sensitivity, selectivity, and intuitive features. Particularly, SPR-based immunosensors could detect biomarkers without labeling of a specific detection probe, as typical immunosensors such as enzyme-linked immunosorbent assay (ELISA) use enzymes like horseradish peroxidase (HRP). In this review, SPR-based immunosensors utilizing noble metals such as Au and Ag as SPR-inducing factors for the measurement of different types of protein biomarkers, including viruses, microbes, and extracellular vesicles (EV), are briefly introduced.

Gold Nano-Island Platforms for Localized Surface Plasmon Resonance Sensing: A Short Review

“…The application of thermally-generated nano-islands to sensing was pioneered by Rubinstein’s group [ 21 , 34 , 35 , 36 , 37 ], and subsequently, many other groups have investigated the optical properties and the sensitivity of various platforms for sensing applications [ 38 , 39 , 40 , 41 ].…”

Recent Progress in Plasmonic Biosensing Schemes for Virus Detection

“…The biocompatibility and easy chemical activation are also significant advantages. Likewise, the large surface area-to-volume ratio provides a higher loading of biological receptors [ 14 , 34 , 35 , 36 ]. Depending on their chemical composition, dimension, and physical properties, common types of plasmonic nanomaterials can vary from metallic nanoparticles and quantum dots to graphene nanostructures (i.e., carbon nanocomposites: Nanotubes, nanosheets, nanoflowers) [ 14 , 37 , 38 , 39 ].…”

“…This implies that the physicochemical properties of the metallic nanoparticles can be tuned to transform LSPR spectra and produce even color variations, generating a signal response [ 19 , 27 ]. Additionally, their high biocompatibility makes possible the functionalization of the surface with a broad range of biological receptors from antibodies to nucleic acids, glycoproteins, and aptamers, thus enabling the selective binding of a variety of analytes [ 35 , 36 ]. Therefore, the utilization of gold and silver nanoparticles in LSPR, SERS, fluorescence enhancement, and colorimetric assays represents a popular approach for detecting small analytes.…”

Surface Plasmon Resonance Sensors for Concentration and Reaction Kinetic Detections

“…The concentrations of the biomarkers are essential information for the early diagnose of disease [30]. The reaction kinetics is a crucial parameter for drug screening [31], biological molecules interactions, and chemical industry.…”