Chapter One demonstrates the applicability of devices based on surface plasmon resonabnce phenomenon (SPR) for investigations in the fields of medicine, veterinary, microbiology, and food industry. Considered here are the results of SPR measurements for two suspensions of erythrocytes – the dense one (erythrocyte mass after centrifuging) and loose solution (whole blood). Chapter Two is focused on the variation of properties in the host liquid crystals (LCs) and dopant gold nanoparticles (GNPs). Surface-induced self-ordering of LC molecules in the vicinity of GNPs has been widely studied in the literature due to the fact that the optical, mechanical and electronic properties of both LCs and GNPs are found modulated to build the next generation of plasmonic devices. In Chapter Three, the authors present an overview of the recent research advances in the field of localized surface plasmon resonance (LSPR) spectroscopy, focusing on the works done to improve LSPR based biosensing by optimizing shape, size, and materials of the nanostructure. They discuss biosensing/bioassay strategies performed on the surface of the noble metal nanostructures focusing on carbohydrate-protein and protein-protein interactions.