title: Designed miniaturization of microfluidic biosensor platforms using the stop-flow technique.
abstract: Here, we present a novel approach to increase the degree of miniaturization as well as the sensitivity of biosensor platforms by the optimization of microfluidic stop-flow techniques independent of the applied detection technique (e.g. electrochemical or optical). The readout of the labeled bioassays, immobilized in a microfluidic channel, under stop-flow conditions leads to a rectangular shaped peak signal. Data evaluation using the peak height allows for a high level miniaturization of the channel geometries. To study the main advantages and limitations of this method by numerical simulations, a universally applicable model system is introduced for the first time. Consequently, proof-of-principle experiments were successfully performed with standard and miniaturized versions of an electrochemical biosensor platform utilizing a repressor protein-based assay for tetracycline antibiotics. Herein, the measured current peak heights are the same despite the sextuple reduction of the channel dimensions. Thus, this results in a 22-fold signal amplification compared to the constant flow measurements in the case of the miniaturized version.
authors.affiliation: Laboratory for Sensors, Department of Microsystems Engineering - IMTEK, University of Freiburg, Germany. dincer@imtek.de and Freiburg Materials Research Center - FMF, University of Freiburg, Germany.
authors.forename: C
authors.identifier: http://orcid.org/0000-0003-3301-1198
authors.initials: C
authors.lastname: Dincer
authors.affiliation: Laboratory for Sensors, Department of Microsystems Engineering - IMTEK, University of Freiburg, Germany. dincer@imtek.de.
authors.forename: A
authors.initials: A
authors.lastname: Kling
authors.affiliation: Centre for Biological Signalling Studies - BIOSS, Germany and Faculty of Biology, University of Freiburg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Chatelle
authors.affiliation: Laboratory for Sensors, Department of Microsystems Engineering - IMTEK, University of Freiburg, Germany. dincer@imtek.de.
authors.forename: L
authors.initials: L
authors.lastname: Armbrecht
authors.affiliation: Laboratory for Sensors, Department of Microsystems Engineering - IMTEK, University of Freiburg, Germany. dincer@imtek.de.
authors.forename: J
authors.initials: J
authors.lastname: Kieninger
authors.affiliation: Centre for Biological Signalling Studies - BIOSS, Germany and Faculty of Biology, University of Freiburg, Germany and Spemann School of Biology and Medicine, University of Freiburg, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Weber
authors.affiliation: Laboratory for Sensors, Department of Microsystems Engineering - IMTEK, University of Freiburg, Germany. dincer@imtek.de and Freiburg Materials Research Center - FMF, University of Freiburg, Germany.
authors.forename: G A
authors.initials: GA
authors.lastname: Urban
mesh_terms: D015374:Biosensing Techniques; D006801:Humans; D046210:Microfluidic Analytical Techniques; D044085:Microfluidics; D008904:Miniaturization; D013754:Tetracyclines / Q000032:analysis / Q000097:blood
chemical_list: D013754:Tetracyclines