skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Ultrasensitive detection of single molecules in flowing sample streams by laser-induced fluorescence

Conference ·
OSTI ID:7183261

We report here on the detection and fluorescence lifetime measurement of single Rhodamine-110 molecules in a flowing, aqueous sample stream. Time-Correlated Photon Counting (TCPC) used in combination with pulsed excitation allows for the detection, in the presence of significant prompt Raman and Rayleigh background, of photon bursts due to single fluorescent molecules passing through a small detection volume ([approximately] 1 pL). The fluorescence lifetime of a detected molecule is estimated from the decay curve compiled from photon arrival times in the burst. An improved SMD apparatus which allows the detection and fluorescent lifetime measurement of individual Rhodamine-110 molecules dissolved in an aqueous sample stream. These measurements are made at a flow rate doser to those that are envisioned for rapid DNA sequencing. We present burst size distributions derived from burst data collected at Rhodamine-110 concentrations of 100 fM and 1 pM and discuss the mechanisms that lead to the observed distributions. We also present Monte Carlo generated synthetic data that supports our interpretation of the experimental results.

Research Organization:
Los Alamos National Lab., NM (United States)
Sponsoring Organization:
USDOE; USDOE, Washington, DC (United States)
DOE Contract Number:
W-7405-ENG-36
OSTI ID:
7183261
Report Number(s):
LA-UR-92-4408; CONF-930159-1; ON: DE93005457
Resource Relation:
Conference: International Society for Optical Engineering (SPIE) conference, Los Angeles, CA (United States), 18-22 Jan 1993
Country of Publication:
United States
Language:
English