In this tutorial review, we summarize and discuss the most recent cutting-edge research in the field of direct surface-enhanced Raman scattering (SERS) analysis of nucleic acids.

Exosomes are emerging as one of the most intriguing cancer biomarkers in modern oncology for early cancer diagnosis, prognosis and treatment monitoring. Concurrently, several nanoplasmonic methods have been applied and developed to tackle the challenging task of enabling the rapid, sensitive, affordable analysis of exosomes. In this review, we specifically focus our attention on the application of plasmonic devices exploiting surface-enhanced Raman spectroscopy (SERS) as the optosensing technique for the structural interrogation and characterization of the heterogeneous nature of exosomes. We summarized the current state-of-art of this field while illustrating the main strategic approaches and discuss their advantages and limitations.

Early diagnosis, monitoring and treatment selection of cancer represent major challenges in medicine. The definition of the complex clinical and molecular landscape of cancer requires the combination of multiple techniques and the investigation of multiple targets. As a result, diagnosis is normally lengthy, expensive and, in many cases, cannot be performed recursively. In recent years, optical biosensors, especially those based on the unique properties of plasmonic nanostructures, have emerged as one of the most exciting tools in nanomedicine, capable of overcoming key limitations of classical techniques. In this review, we specifically focus our attention on the latest advances in optical biosensors exploiting surface-enhanced Raman scattering encoded particles for the characterization of tumor single cells (molecular biology) and tissues (immunohistochemistry and guided surgery), as well as their application in guided surgery or even in bioimaging of living organisms.