Surface plasmon-enhanced super-localization microscopy

Super-resolution microscopy has drawn tremendous interests because it allows precise tracking of molecular interactions and observation of dynamics on a nanometer scale. Intracellular and extracellular processes can be measured at the molecular level; thus, super-resolution techniques help in the understanding of biomolecular events in cellular and sub-cellular conditions and have been applied to many areas such as cellular and molecular analysis and ex vivo and in vivo observation. In this chapter, we review near-field imaging that relies on evanescent waves such as TIRFM with an emphasis on super-resolution microscopy techniques that emerge recently based on excitation and localization of SP. In particular, three approaches are detailed: firstly, SUPRA imaging that employs the electromagnetic localization of near-fields by random nanopatterns; secondly, NLS that capitalizes on nanoscale fluorescence sampling at periodic nanoapertures; and finally, PSALM that depends on temporal switching of amplified local fields for enhancement of imaging resolution. The resolution typically achieved by these techniques is laterally below 100 nm and closely related to the size of a near-field hot spot and nanostructures used to localize SP.We expect the achievable imaging resolution to decrease significantly in the near future.