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Proceedings Paper

Spectrally resolved anti-Brownian electrokinetic (ABEL) trapping of single peridinin-chlorophyll-proteins in solution
Author(s): Samuel D. Bockenhauer; Quan Wang; W. E. Moerner
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Paper Abstract

We use an Anti-Brownian ELectrokinetic (ABEL) trap to probe spectral emission shifts in solution-phase single Peridinin-Chlorophyll-Proteins (PCPs). The ABEL trap allows localization of single biomolecules in solution in a small volume for extended observation without immobilization. The essential idea combines fluorescence-based position estimation with fast electrokinetic feedback in a microfluidic geometry to counter the Brownian motion of a single nanoscale object, hence maintaining its position in a sub-micron-sized field of view for hundreds of milliseconds to seconds. Peridinin-chlorophyll-protein is a water-soluble antenna protein found in dinoflagellates which uses peridinins (carotenoids) as accessory light harvesting pigments to absorb sunlight in the green region of the spectrum before transferring electronic excitation to chlorophyll. PCP is simpler than many other antenna complexes in that there are only two chlorophyll pigments per monomer which do not form an exciton. We use the ABEL trap to study single PCP monomers in solution for several seconds each. A significant fraction of the molecules show slow spectral shifts (spectral diffusion) relative to the bulk PCP spectrum. This is the first spectral emission measurement conducted in the ABEL trap.

Paper Details

Date Published: 8 May 2012
PDF: 9 pages
Proc. SPIE 8427, Biophotonics: Photonic Solutions for Better Health Care III, 84274C (8 May 2012); doi: 10.1117/12.970546
Show Author Affiliations
Samuel D. Bockenhauer, Stanford Univ. (United States)
Quan Wang, Stanford Univ. (United States)
W. E. Moerner, Stanford Univ. (United States)

Published in SPIE Proceedings Vol. 8427:
Biophotonics: Photonic Solutions for Better Health Care III
Jürgen Popp; Wolfgang Drexler; Valery V. Tuchin; Dennis L. Matthews, Editor(s)

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