Nonlinear Optical Chromophores as Nanoscale Emitters for Single-Molecule Spectroscopy

Department of Chemistry and Biochemistry, Kent State University, Кент, Ohio, United States
Accounts of Chemical Research (Impact Factor: 24.35). 08/2005; 38(7):549-56. DOI: 10.1021/ar0401294
Source: PubMed

ABSTRACT Fluorescence imaging of single molecules at room temperature is a powerful technique for studying complex condensed phase systems and revealing structure and dynamics hidden by ensemble measurements. Successful single-molecule spectroscopic experiments rely upon strong emitters that can be detected at the level of individual copies above the relevant background signals. This Account discusses a class of nonlinear optical chromophores that not only are well-suited for single-molecule imaging but also offer additional beneficial properties such as a significant ground-state dipole moment, moderate hyperpolarizability, and sensitivity to local environment. An overview of the photophysical properties of several members of this class of molecules as well as a mechanism to help understand the environmental sensitivity is presented. Some preliminary applications of the chromophores as single-molecule reporters in cellular and polymer systems are discussed, along with detection of the emitters by two-photon fluorescence.

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