title: Coplanar electrode microfluidic chip enabling accurate sheathless impedance cytometry.
abstract: Microfluidic impedance cytometry offers a simple non-invasive method for single-cell analysis. Coplanar electrode chips are especially attractive due to ease of fabrication, yielding miniaturized, reproducible, and ultimately low-cost devices. However, their accuracy is challenged by the dependence of the measured signal on particle trajectory within the interrogation volume, that manifests itself as an error in the estimated particle size, unless any kind of focusing system is used. In this paper, we present an original five-electrode coplanar chip enabling accurate particle sizing without the need for focusing. The chip layout is designed to provide a peculiar signal shape from which a new metric correlating with particle trajectory can be extracted. This metric is exploited to correct the estimated size of polystyrene beads of 5.2, 6 and 7 μm nominal diameter, reaching coefficient of variations lower than the manufacturers' quoted values. The potential impact of the proposed device in the field of life sciences is demonstrated with an application to Saccharomyces cerevisiae yeast.
authors.affiliation: Department of Civil Engineering and Computer Science, University of Rome Tor Vergata, via del Politecnico 1, 00133 Rome, Italy. bisegna@uniroma2.it caselli@ing.uniroma2.it.
authors.forename: Adele
authors.initials: A
authors.lastname: De Ninno
authors.affiliation: Department of Civil Engineering and Computer Science, University of Rome Tor Vergata, via del Politecnico 1, 00133 Rome, Italy. bisegna@uniroma2.it caselli@ing.uniroma2.it.
authors.forename: Vito
authors.identifier: 0000-0003-1229-7449
authors.initials: V
authors.lastname: Errico
authors.affiliation: Italian National Research Council - Institute for Photonics and Nanotechnologies (CNR - IFN), via Cineto Romano 42, 00156 Rome, Italy.
authors.forename: Francesca Romana
authors.initials: FR
authors.lastname: Bertani
authors.affiliation: Italian National Research Council - Institute for Photonics and Nanotechnologies (CNR - IFN), via Cineto Romano 42, 00156 Rome, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Businaro
authors.affiliation: Department of Civil Engineering and Computer Science, University of Rome Tor Vergata, via del Politecnico 1, 00133 Rome, Italy. bisegna@uniroma2.it caselli@ing.uniroma2.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Bisegna
authors.affiliation: Department of Civil Engineering and Computer Science, University of Rome Tor Vergata, via del Politecnico 1, 00133 Rome, Italy. bisegna@uniroma2.it caselli@ing.uniroma2.it.
authors.forename: Federica
authors.identifier: 0000-0001-6663-8603
authors.initials: F
authors.lastname: Caselli
mesh_terms: D017097:Electric Impedance; D004566:Electrodes; D005434:Flow Cytometry / Q000379:methods*; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D010316:Particle Size; D011137:Polystyrenes; D015003:Yeasts / Q000166:cytology
chemical_list: D011137:Polystyrenes