Raman spectroscopy is a valuable tool in various research fields. The technique yields structural information from all kind
of samples often without the need for extensive sample preparation. Since the Raman signals are inherently weak and therefore
do not allow one to investigate substances in low concentrations, one possible approach is surface-enhanced (resonance) Raman
spectroscopy. Here, rough coin metal surfaces enhance the Raman signal by a factor of 104–1015, depending on the applied method. In this review we discuss recent developments in SERS spectroscopy and their impact on
different research fields.