In Honor of W.E. Moerner: Confining Molecules for Single-Molecule Spectroscopy

Abstract

Single-molecule spectroscopy provides a wealth of information on the dynamics and interactions of complex biological molecules. Yet these measurements are extremely challenging, partly because Brownian motion prevents molecules in free solution from remaining stationary. Here we describe several techniques that our lab has developed for confining single molecules for optical spectroscopy. These alternatives to surface immobilization provide confinement that is gentle enough to minimize perturbations to the molecule, but strong enough to allow long-time imaging of single fluorescent molecules, often in the presence of a high fluorescent background.