ABSTRACT
In this chapter, we discuss optical spectroscopic techniques developed for single-molecule detection (SMD). These techniques include laser-induced fluorescence (LIF), near-field scanning optical microscopy (NSOM), surface-enhanced Raman spectroscopy (SERS) and “optical tweezers.” Due to their non-invasiveness and high sensitivity to changes in molecular conformation and environment, these techniques are especially suitable for applications in SMD. They not only allow us to detect and image single molecules, but also to conduct spectroscopic measurements and monitor dynamic processes. First of all, we outline the basic requirements for SMD and discuss how these requirements can be fulfilled in different ways. Then, we review the latest developments in optical single-molecule techniques: the principle of each technique is described followed by a discussion of the potential offered by each technique for SMD applications. Finally, selected examples of SMD, particularly for monitoring of cellular events and activities, are given.
