title: Electrical detection of dsDNA and polymerase chain reaction amplification.
abstract: Food-borne pathogens and food safety-related outbreaks have come to the forefront over recent years. Estimates on the annual cost of sicknesses, hospitalizations, and deaths run into the billions of dollars. There is a large body of research on detection of food-borne pathogens; however, the widely accepted current systems are limited by costly reagents, lengthy time to completion, and expensive equipment. Our aim is to develop a label-free method for determining a change in DNA concentration after a PCR assay. We first used impedance spectroscopy to characterize the change in concentration of purified DNA in deionized water within a microfluidic biochip. To adequately measure the change in DNA concentration in PCR solution, it was necessary to go through a purification and precipitation step to minimize the effects of primers, PCR reagents, and excess salts. It was then shown that the purification and precipitation of the fully amplified PCR reaction showed results similar to the control tests performed with DNA in deionized water. We believe that this work has brought label free electrical biosensors for PCR amplification one step closer to reality.
authors.affiliation: Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Salm
authors.forename: Yi-Shao
authors.initials: YS
authors.lastname: Liu
authors.forename: Daniel
authors.initials: D
authors.lastname: Marchwiany
authors.forename: Dallas
authors.initials: D
authors.lastname: Morisette
authors.forename: Yiping
authors.initials: Y
authors.lastname: He
authors.forename: Laila
authors.initials: L
authors.lastname: Razouk
authors.forename: Arun K
authors.initials: AK
authors.lastname: Bhunia
authors.forename: Rashid
authors.initials: R
authors.lastname: Bashir
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics*; D055615:Electrical Equipment and Supplies; D004867:Equipment Design; D008089:Listeria monocytogenes / Q000166:cytology* / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results
chemical_list: D017931:DNA Primers; D004269:DNA, Bacterial