Berlin 2015 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 1: Imaging

BP 1.6: Vortrag

Montag, 16. März 2015, 11:00–11:15, H 1028

Label-free optical detection of single proteins — •Katharina König, Marek Piliarik, and Vahid Sandoghdar — Max Planck Institute for the Science of Light, Erlangen, Germany

Detection of small amounts of biomolecules down to the single molecule level is highly desirable in a variety of fundamental and technological investigations. Conventional modern methods rely on strong fluorescence or absorption properties of marker molecules. However, labeling strategies have many disadvantages since they are nontrivial to implement and can often alter the behavior of analyte molecules. In this work we report on the direct, optical detection of single proteins without the need for any labels. This sensitivity is achieved via interferometric detection of the scattering (iSCAT) from a single protein. By combining this approach with microfluidics and functionalized surfaces, we are able to count single protein binding events and localize their positions with a precision of 5 nm. A wide-field detection arrangement and direct protein imaging capability make the method readily suitable for biomolecular analytics, outperforming previously reported label-free sensing approaches. We will show first emerging applications in ultra sensitive single-cell analysis.