Sonochemical synthesis and bioconjugation of highly fluorescent, water soluble quantum dots for single molecule imaging on phospholipid membranes
Abstract
The field of single molecule tracking based on gold and dye-labeled tracer molecules has been instrumental in changing the view about the structure-dynamics-function relationships in cellular membranes. However, these traditional probes are limited concerning their size and photostability, respectively. This work presents the successful development of a sonochemical synthesis method for high-quality CdSe/ZnS quantum dots, and their subsequent characterization. Also reported is the design of a new quantum dot-based probe for single molecule imaging on phospholipid membranes. Nanocrystal coatings were especially designed for direct conjugation of these small, photostable, water soluble CdSe/ZnS quantum dots to membrane-bound phospholipids in model membranes and on cell surfaces. Using wide-field single molecule fluorescence microscopy, the trajectories of the quantum dot-labeled lipids were studied, and 1:1 quantum dot:phospholipid labeling was verified. The small size (<10nm) and high photostability of these custom-built, state of the art imaging probes is particularly interesting for fluorescence-based molecular imaging where high sensitivity is required. Results from tracking experiments on dye and quantum dot-conjugated lipids in model and cell membranes are provided, which verify the biocompatibility and bioconjugation of the quantum dot probes developed in this work.
Degree
Ph.D.
Advisors
Naumann, Purdue University.
Subject Area
Chemistry
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