Applications of Raman and Surface-Enhanced Raman Scattering to the Analysis of Eukaryotic Samples - Emerging Raman Applications and Techniques in Biomedical and Pharmaceutical Fields - page 69

4
Applications of Raman and Surface-Enhanced
Raman Scattering to the Analysis
of Eukaryotic Samples
Franziska Schulte, Virginia Joseph, Ulrich Panne, and Janina Kneipp
Abstract In this chapter, we discuss Raman scattering and surface-enhanced
Raman scattering (SERS) for the analysis of cellular samples of plant and animal
origin which are several tens to hundreds of microns in size. As was shown in the past
several years, the favorable properties of noble metal nanostructures can be used to
generate SERS signals in very complex biological samples such as cells, and result
in an improved sensitivity and spatial resolution. Pollen grains, the physiological
containers that produce the male gametes of seed plants, consist of a few vegetative
cells and one generative cell, surrounded by a biopolymer shell. Their chemical com-
position has been a subject of research of plant physiologists, biochemists [1, 2], and
lately even materials scientists [3, 4] for various reasons. In spite of a multitude of
applied analytical approaches it could not be elucidated in its entirety yet. Animal
cells from cell cultures have been a subject of intense studies due to their appli-
cation in virtually all fields of biomedical research, ranging from studies of basic
biological mechanisms to models for pharmaceutical and diagnostic research. Many
aspects of all kinds of cellular processes including signalling, transport, and gene
regulation have been elucidated, but many more facts about cell biology will need
to be understood in order to eciently address issues such as cancer, viral infection
or genetic disorder. Using the information from spectroscopic methods, in particular
combining normal Raman spectroscopy and SERS may open up new perspectives
on cellular biochemistry. New sensitive Raman-based tools are being developed for
the biochemical analysis of cellular processes [5-8].
4.1 Surface-Enhanced Raman Scattering
and its Applications to Bioanalytical Chemistry
As demonstrated by numerous papers, including the chapters of this and other
topics, Raman spectroscopy has long been used for the analysis of biological
samples. In the inelastic Raman scattering process, photons from a laser source
interact with the molecular vibrations of a sample, yielding scattered photons
with a changed energy. The energy difference corresponds to the energy of
the molecular vibration the photons interacted with. The resulting spectra