Fundamental understanding and applications of plasmon-enhanced Raman spectroscopy

Abstract

Plasmon-enhanced Raman spectroscopy (PERS), including surface-enhanced Raman spectroscopy, shell-isolated nanoparticle-enhanced Raman spectroscopy, and tip-enhanced Raman spectroscopy has received increasing interest. It can provide fingerprint information on target materials with sensitivity down to the single-molecule level, and with sufficient spatial resolution to observe individual vibration modes. Over the past four decades, PERS has found important applications in surfaces and interfaces, analytical sciences (including small molecules, biomolecules, and living cells), and material sciences. In this Technical Review, we survey the basic principles, advantages, and limitations of using the localized surface plasmon resonance to boost the PERS, and provide the insights gained from the understanding of the electromagnetic enhancement and chemical enhancement. We then discuss practical issues that may significantly influence the sensitivity and the correct understanding of PERS results. We overview the state-of-the-art PERS applications in surfaces and interfaces, materials, and biology. We provide troubleshooting methods that may be helpful in practical experiments, based on our own experiences. We conclude with the future trends and issues to be addressed for the further development of PERS techniques.