Optical dark-field spectroscopy of single plasmonic nanoparticles for molecular biosciences

An ideal sensor capable of quantifying analytes in minuscule sample volumes represents a significant technological advancement. Plasmonic nanoparticles integrated with optical dark-field spectroscopy have reached this capability, demonstrating versatility and expanding applicability across in vitro and in vivo subjects. This review underscores the applicability of optical dark-field spectroscopy with single plasmonic nanoparticles to elucidate a wide range of biomolecular characteristics, including binding constants, molecular dynamics, distances, and forces, as well as recording cell communication signals. Perspectives highlight the potential for the development of implantable nanosensors for metabolite detection in animal models, illustrating the technique's efficacy without the need for labeling molecules. In summary, this review aims to consolidate knowledge of this adaptable and robust technique for decoding molecular biological phenomena within the nano- and bio-scientific community. This review examines the use of gold nanoparticles as sensors in biomolecular science through optical dark-field spectroscopy, applied to systems such as DNA, proteins, complexes, and cells, with potential for in vivo applications soon.