multi-color single particle tracking with quantum dots多色量子点单粒子跟踪.pdfVIP

Multi-Color Single Particle Tracking with Quantum Dots Eva C. Arnspang1,3, Jonathan R. Brewer2,3, B. Christoffer Lagerholm1,3* 1 Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense M, Denmark, 2 Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark, 3 MEMPHYS – Center for Biomembrane Physics, and DaMBIC – Danish Molecular Biomedical Imaging Center, University of Southern Denmark, Odense M, Denmark Abstract Quantum dots (QDs) have long promised to revolutionize fluorescence detection to include even applications requiring simultaneous multi-species detection at single molecule sensitivity. Despite the early promise, the unique optical properties of QDs have not yet been fully exploited in e. g. multiplex single molecule sensitivity applications such as single particle tracking (SPT). In order to fully optimize single molecule multiplex application with QDs, we have in this work performed a comprehensive quantitative investigation of the fluorescence intensities, fluorescence intensity fluctuations, and hydrodynamic radii of eight types of commercially available water soluble QDs. In this study, we show that the fluorescence intensity of CdSe core QDs increases as the emission of the QDs shifts towards the red but that hybrid CdSe/ CdTe core QDs are less bright than the furthest red-shifted CdSe QDs. We further show that there is only a small size advantage in using blue-shifted QDs in biological applications because of the additional size of the water-stabilizing surface coat. Extending previous work, we finally also show that parallel four color multicolor (MC)-SPT with QDs is possible at an image acquisition rate of at least 25 Hz. We demonstrate the technique by measuring the lateral dynamics of a li