Handheld imaging photonic crystal biosensor for multiplexed, label-free protein detection.
We present a handheld biosensor system for the label-free and specific multiplexed detection of several biomarkers employing a spectrometer-free imaging measurement system. A photonic crystal surface functionalized with multiple specific ligands forms the optical transducer. The photonic crystal slab is fabricated on a glass substrate by replicating a periodic grating master stamp with a period of 370 nm into a photoresist via nanoimprint lithography and deposition of a 70-nm titanium dioxide layer. Capture molecules are coupled covalently and drop-wise to the photonic crystal surface. With a simple camera and imaging optics the surface-normal transmission is detected. In the transmission spectrum guided-mode resonances are observed that shift due to protein binding. This shift is observed as an intensity change in the green color channel of the camera. Non-functionalized image sections are used for continuous elimination of background drift. In a first experiment we demonstrate the specific and time-resolved detection of 90.0 nm CD40 ligand antibody, 90.0 nM EGF antibody, and 500 nM streptavidin in parallel on one sensor chip. In a second experiment, aptamers with two different spacer lengths are used as receptor. The binding kinetics with association and dissociation of 250 nM thrombin and regeneration of the sensor surface with acidic tris-HCl-buffer (pH 5.0) is presented for two measurement cycles.
Institute of Electrical and Information Engineering, Christian-Albrechts-Universität zu Kiel, Germany.
Sabrina
S
Jahns
Department of Medicine III and Transfusion Medicine, University Hospital Grosshadern, LMU, Munich, Germany.
Marion
M
Bräu
Institute of Electrical and Information Engineering, Christian-Albrechts-Universität zu Kiel, Germany.
Björn-Ole
BO
Meyer
Institute of Electrical and Information Engineering, Christian-Albrechts-Universität zu Kiel, Germany.
Torben
T
Karrock
Institute for Materials Science, Christian-Albrechts-Universität zu Kiel, Germany.
Sören B
SB
Gutekunst
Biotechnical Microsystems, Fraunhofer Institute of Silicon Technology, Germany.
Lars
L
Blohm
Institute for Materials Science, Christian-Albrechts-Universität zu Kiel, Germany.
Christine
C
Selhuber-Unkel
Department of Medicine III and Transfusion Medicine, University Hospital Grosshadern, LMU, Munich, Germany.
Raymund
R
Buhmann
Institute of Electrical and Information Engineering, Christian-Albrechts-Universität zu Kiel, Germany.
Yousef
Y
Nazirizadeh
Institute of Electrical and Information Engineering, Christian-Albrechts-Universität zu Kiel, Germany.
Martina
M
Gerken
(110.2970) Image detection systems; (170.0170) Medical optics and biotechnology; (220.4241) Nanostructure fabrication; (280.4788) Optical sensing and sensors; (350.4238) Nanophotonics and photonic crystals