The elucidation of the biological function of proteins in metabolism is one of the most significant disciplines in the life sciences. The search for marker proteins that directly correlate with pathological changes in metabolism plays a central role in this context. By combining interdisciplinary methods for qualitative and quantitative detection, a comprehensive characterization of proteins or protein mixtures is currently possible. The detection methods employed typically rely on elaborate and costly labeling of the proteins. This work evaluates the potential of Raman spectroscopy, focusing on surface-enhanced Raman spectroscopy as a non-invasive, label-free, and optical detection method for protein analytics. In addition to the technical implementation of a highly sensitive Raman spectrometer, various strategies to enhance detection sensitivity are pursued. Based on nanostructured metal surfaces, qualitative and quantitative measurements of selected proteins in the fmol range are presented.