Nanosensors for intracellular Raman studies

Raman spectroscopy is an increasingly exploited tool for the study of cell biology, and the focus of this chapter is surface-enhanced Raman spectroscopy (SERS). Using SERS, noble metal nanoparticles can be interrogated with wavelengths of light to which cells exhibit minimal autofluorescence and return useful information about their immediate chemical environment. Using established gold–thiol surface chemistry, gold nanoparticles can be functionalised with suitable reporter molecules used to make nanosensors, which can be chosen to be sensitive to intracellular variables such as pH, protein concentration/activity or redox potential. This chapter presents the general concept of SERS for use in the monitoring of intracellular variables, and we will describe the preparation, use and functions of the nanosensors.