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BP: Fachverband Biologische Physik

BP 12: Poster II

BP 12.62: Poster

Dienstag, 2. April 2019, 14:00–16:00, Poster B2

Optimizing PDMS Stamp Transfer Preparation of MoS₂-Nanopores for DNA Translocation Experiments with Optical Tweezers — •Julian Cremer¹, Inga Ennen², Sebastian Knust¹, Martina Viefhues¹, and Dario Anselmetti¹ — ¹Experimental Biophysics and Applied Nanoscience, Bielefeld University, Germany — ²Thin Films & Physics of Nanostructures, Bielefeld University, Germany

To better understand the translocation of biological molecules through nanopores we measure the forces acting on λ-DNA during a translocation through solid-state nanopores with Optical Tweezers. For high sensitivity, we milled pores smaller than 10 nm with a transmission electron microscope (TEM) in freestanding MoS₂-monolayers with a thickness of 0.67 nm.

The defect-free MoS₂-monolayers are produced by a simple but efficient viscoelastic PDMS stamp transfer technique. Since the contact with PDMS causes minute but nevertheless relevant residues on the MoS₂ we investigated the removal of these residues particularly with regard to enable nanopore experiments. Thus, we performed high resolution TEM as well as atomic force microscopy (AFM) measurements to optimize the preparation. These include pretreatments of the PDMS e. g. UV-ozone cleaning as well as variations of the PDMS stamp thicknesses and steps after the transfer like annealing or plasma treatment.

In this work we present first results towards the preparation of freestanding residue-free MoS₂-nanopores and controlled translocation experiments.