Gold nanoparticles have attracted and raised interest due to their potential applications in chemical and biochemical sensing for low traces molecule detection, in tumor ablation, and Lab-On Chip technologies. In this context, we actually develop new gold nanoparticles (GNPs) synthesis method which is based on the use of polymer nanoporous structures as reactors for GNPs elaboration. The process is gold precursor-loaded polymer self-assembly-induced the formation of GNPs. In the present project, we aim to understand the mechanism behind the formation of uniform NPs. Thus, a physico-chemical study based on the variation of the experimental parameters is required to tune the optical and physical properties of GNPs. Such structural properties are generally difficult to obtain by chemical ways as compared to our process. Moreover, the control of NPs shape and size will allow us to determine the plasmon band of the NPS and to define their sensing features. Then, bio-sensing measurements based on SERS (Surface Enhanced Raman Spectroscopy) phenomenon and using bacteria as target molecules will be performed in order to evaluate the SERS enhancement factor of the synthesized systems.