LSPR as an optical phenomenon can be detected via various optical techniques, the most common being light extinction, scattering and reflectance spectroscopy. Depending on the structure of the nanoscale metal particles, these methods are employed for solution-based, single-nanoparticle and nanoparticle arrays measurement modes. Each approach has its own features, but the common principle is that the LSPR response is primarily defined by the LSPR properties of individual nanoparticle.
Fig. 1 shows the typical setup employed for light-extinction-based LSPR spectroscopy. When the light source illuminates gold nanoparticles in a solution or on a solid substrate, strong light absorption and scattering occurs leading to the extinction of incident light with a characteristic peaking spectral distribution (Fig. 2), which can be registered by means of UV-Vis spectrometer.