Polymer dot nanoparticles as single molecule probes

PHYS 22

Jason D. McNeill, mcneill@CLEMSON.EDU, Craig J. Szymanski, cszyman@clemson.edu, Changfeng Wu, cwu@clemson.edu, and Mary Alice Salazar, salazar@clemson.edu. Department of Chemistry, Clemson University, 365 Hunter, Clemson University, Clemson, SC 29634
A key obstacle to further advances in single molecule spectroscopy is the lack of fluorescent tags which are sufficiently bright and photostable. We have developed a general method for producing aqueous suspensions of small (~3-10 nm) nanoparticles ("Polymer Dots") consisting of single molecules of fluorescent conjugated polymers. Polymer dot fluorescence brightness is hundreds of times higher than that of conventional fluorescent dyes (as determined from fluorescence spectroscopy, near-field scanning optical microscopy and single molecule spectroscopy results). Methods for encapsulation and bioconjugation of the nanoparticles were also developed. FRET-based sensing schemes were also demonstrated. The suitability of the nanoparticles for multiphoton fluorescence, in vivo single molecule detection, and molecule tracking is also explored.