This chapter gives an overview of the main optical methods used to detect and study single molecules and other small objects (nano-objects). Much of the work so far has exploited the excellent sensitivity and selectivity of fluorescence, but several new techniques, mostly based on nonlinear optics, have recently reached the single-molecule or single-nanoparticle regime. The chapter briefly discusses some results with reference to published reviews. Single-molecule techniques have now been incorporated into the arsenal of the physico-chemist and the cell biologist. However, the recent development of super-resolution techniques and of new labels suggests that further progress can be expected from measurements on single nano-objects in the next few years.
Nobel Lecture: Single-molecule spectroscopy, imaging, and photocontrol: Foundations for super-resolution microscopy
