Abstract

Over the past five years, several groups have developed the capability to detect and identify single fluorescent molecules in solution as the molecules flow through a focused laser beam. The history of the approach to single-molecule detection in fluid solution is shown in Fig. 1. Approximately one dozen molecular species have been detected at this level of sensitivity. Fluorescence-based, single-molecule detection techniques are expected to have a significant impact in fields where fluorescence detection and quantification are broadly applied, e.g., analytical chemistry, biology, and medicine. Single-molecule detection is a new way of doing analytical chemistry, and new applications will arise. In this article, we describe our approach to single-molecule detection and explore assays that can be done at the single-species level that would be difficult or impossible with bulk measurements.

Detection and identification of single molecules in solution

Steven A. Soper, Lloyd M. Davis, and E. Brooks Shera
J. Opt. Soc. Am. B 9(10) 1761-1769 (1992)

Rapid and efficient detection of single chromophore molecules in aqueous solution

Li-Qiang Li and Lloyd M. Davis
Appl. Opt. 34(18) 3208-3217 (1995)

A Bayesian method for single molecule, fluorescence burst analysis

P. R. Barber, S. M. Ameer-Beg, S. Pathmananthan, M. Rowley, and A. C. C. Coolen
Biomed. Opt. Express 1(4) 1148-1158 (2010)

Single-molecule analysis of ultradilute solutions with guided streams of 1-µm water droplets

Chung-yi Kung, Michael D. Barnes, Noah Lermer, William B. Whitten, and J. Michael Ramsey
Appl. Opt. 38(9) 1481-1487 (1999)

Single-molecule detection: applications to ultrasensitive biochemical analysis

Alonso Castro and E. Brooks Shera
Appl. Opt. 34(18) 3218-3222 (1995)