title: Resonance-enhanced microfluidic impedance cytometer for detection of single bacteria.
abstract: This paper reports on a novel impedance-based cytometer, which can detect and characterize sub-micrometer particles and cells passing through a microfluidic channel. The cytometer incorporates a resonator, which is constructed by means of a discrete inductor in series with the measurement electrodes in the microfluidic channel. The use of a resonator increases the sensitivity of the system in comparison to state-of-the-art devices. We demonstrate the functionality and sensitivity of the cytometer by discriminating E. coli and B. subtilis from beads of similar sizes by means of the resonance-enhanced phase shift of the current through the microfluidic channel. The phase shift can be correlated to size and dielectric properties of the measured objects.
authors.affiliation: ETH Zurich, Dept. of Biosystems Science and Engineering, Mattenstrasse 26, Basel, CH-4058, Switzerland. niels.haandbaek@bsse.ethz.ch.
authors.forename: Niels
authors.initials: N
authors.lastname: Haandbæk
authors.forename: Oliver
authors.initials: O
authors.lastname: With
authors.forename: Sebastian C
authors.initials: SC
authors.lastname: Bürgel
authors.forename: Flavio
authors.initials: F
authors.lastname: Heer
authors.forename: Andreas
authors.initials: A
authors.lastname: Hierlemann
mesh_terms: D001419:Bacteria / Q000302:isolation & purification*; D057230:Limit of Detection; D044085:Microfluidics / Q000295:instrumentation*