Fluorescence Intermittency and Spectral Shifts of Single Bio-Conjugated Nanocrystals Studied by Single Molecule Confocal Fluorescence Microscopy and Spectroscopy

Published

January 21, 2007

Author(s)

Hyeong G. Kang, Mathew Maye, Dmytro Nykypanchuk, Matthew L. Clarke, Peter Yim, J R. Krogmeier, Kimberly A. Briggman, Oleg Gang, Jeeseong Hwang

Abstract

We have fabricated a combined measurement system capable of confocal microscopy and fluorescence spectroscopy to simultaneously evaluate multiple optical characteristics of single fluorescent nanocrystals. The single particle detection sensitivity is demonstrated by simultaneously measuring the dynamic excitation-time-dependent fluorescence intermittency and the emission spectrum of single cadmium selenide/zinc sulfide (CdSe/ZnS) nanocrystals (quantum dots, QDs). Using this system, we are currently investigating the optical characteristics of single QDs, the surface of which are conjugated with different ligands, such as trioctylphosphine oxide (TOPO), mercaptoundecanoicacid (MDA), and amine modified DNA (AMDNA). In this paper, we present the progress of our measurements of the time-dependent optical characteristics (fluorescence intermittency, photostability, and spectral diffusion) of single MDA-QDs and AMDNA-MDA-QDs in air in an effort to understand the effects of surface-conjugated biomolecules on the optical characteristics at single QD sensitivities.

Proceedings Title

Proceedings of the SPIE Conference | 2007 | SPIE

Volume

6430

Conference Dates

January 23-24, 2007

Conference Title

SPIE Conference Proceedings

Pub Type

Conferences

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Keywords

bio-conjugation, confocal microscopy, nanocrystal, nanosensor, photophysics, single nanocrystal, single quantum dot

Citation

Kang, H. , Maye, M. , Nykypanchuk, D. , Clarke, M. , Yim, P. , Krogmeier, J. , Briggman, K. , Gang, O. and Hwang, J. (2007), Fluorescence Intermittency and Spectral Shifts of Single Bio-Conjugated Nanocrystals Studied by Single Molecule Confocal Fluorescence Microscopy and Spectroscopy, Proceedings of the SPIE Conference | 2007 | SPIE, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=841080 (Accessed October 7, 2025)