Biosensing with a scanning planar Yagi-Uda antenna
Authors: Soltani N., Rabbany Esfahany E., Druzhinin S.I., Schulte G., Müller J., Butz B., Schönherr H., Agio M., Markešević N.
Autors Affiliation: Laboratory of Nano-Optics, University of Siegen, Siegen 57072, Germany; Research Center of Micro- and Nanochemistry and (Bio)Technology (Cμ), Siegen 57076, Germany; Physical Chemistry I, University of Siegen, Siegen 57076, Germany; Micro- and Nanoanalytics Group, University of Siegen, Siegen 57076, Germany; National Institute of Optics (INO), National Research Council (CNR), Florence 50125, Italy; Currently with Nanoscience Center, University of Jyväskylä, Jyväskylä 40014, Finland
Abstract: We investigate a model bioassay in a liquid environment using a z-scanning planar Yagi-Uda antenna, focusing on the fluorescence collection enhancement of ATTO-647N dye conjugated to DNA (deoxyribonucleic acid) molecules. The antenna changes the excitation and the decay rates and, more importantly, the emission pattern of ATTO-647N, resulting in a narrow emission angle (41°) and improved collection efficiency. We efficiently detect immobilized fluorescently-labeled DNA molecules, originating from solutions with DNA concentrations down to 1 nM. In practice, this corresponds to an ensemble of fewer than 10 ATTO-647N labeled DNA molecules in the focal area. Even though we use only one type of biomolecule and one immobilization technique to establish the procedure, our method is versatile and applicable to any immobilized, dye-labeled biomolecule in a transparent solid, air, or liquid environment.
Journal/Review: BIOMEDICAL OPTICS EXPRESS
Volume: 13 Pages from: 539 to: 548