Plasmonic materials based on noble metal nanostructures exhibit unique optical properties in the visible range. Currently, plasmons supported by metal nanoparticles or propagating along metal interfaces are attracting increasing attention in sensorics, medicine, imaging, nanophotonics, and optoelectronic technologies. This article has provided a brief overview of two main plasmonic modes: surface plasmon polaritons at metal interfaces and localized plasmons in nanostructures. It also discussed the physical principles of plasmon-enhanced sensors, such as colorimetric, plasmon-enhanced fluorescence, and surface enhanced Raman scattering ones. These sensors are widely used in healthcare, security, food processing, and environmental monitoring. The fabrication of plasmonic nanostructures in glasses using ion exchange and their application for detecting chemical compounds and biological objects was discussed.