Exosomes are extracellular vesicles containing proteins, glycoproteins, lipids, integrins, nucleic acids and other cargo. Exosomes are emitted by all cell types and are believed to play a role in inter-cellular signalling. Their sizes range from 30nm-150nm. It is believed that their cargo content can change significantly when their originating cell type becomes diseased and their cargo can be assessed through the use of Raman Spectroscopy. As for many biomolecules, Raman scattering signal intensity is low. To achieve a sufficient Raman signal intensity typically requires samples with a high density of exosomes present. One way to overcome the low signal intensity is to employ Surface Enhanced Raman Spectroscopy. Wherein by capturing exosomes on appropriate SERS substrates upon photon excitation the generation of a plasmonic field significantly enhances Raman intensity by up to 1010, this allows the use of small quantities of label free exosomes thereby making single molecular detection possible. The primary objective of this thesis involve the fabrication and selective surface modification of Au micro array platforms and subsequent application for label-free exosome capture. Once the functionalization of the Au micro platform has been optimised, the optimised platform is then used for the secondary objective which is to generate a training database of different exosomal populations in collaboration with computer scientists. To generate an effective surface enhanced signal, it is important to drive the analyte to the location of maximum plasmonic field. This is achieved by using Selective Surface modification techniques which is the key achievement of Chapter 3. The exterior of the micro-arrays is selectively modified with an alkane thiol self-assembled monolayer (using micro-contact printing) to prevent exosome adhesion and the interior is modified with a self- assembled (c)-RGDFK peptide monolayer. This particular peptide sequence will promote integrin conjugation, cell and other biomaterial adhesion and will conjugate with any exosome present and allow an effective signal to be generated within the plasmonic field. The Au micro array interiors are also functionalized using thiocholesterol for comparison. Other key achievements of this thesis are presented in Chapter 4 which involve the application of selectively modified Au micro array platforms. Their array pore interiors are functionalized using both (c)-RGD peptide and thiocholesterol and exosome capture of both types of selectively modified platforms are assessed using two different types of exosome populations. One sourced from immortalized cells and the other from primary cells. The final outcome of this thesis is presented in Chapter 5. This involves the generation of a training database set of three different types of exosomal sub-populations of primary human aortic endothelial cardiac cells captured exclusively within a (c)-RGD functionalized Au micro array platform and these exosomal sub-populations are subsequently interrogated using Surface Enhanced Raman Spectroscopy and Field Emission Scanning Electron Microscopic techniques.