title: Detection of target ssDNA using a microfabricated Hall magnetometer with correlated optical readout.
abstract: Sensing biological agents at the genomic level, while enhancing the response time for biodetection over commonly used, optics-based techniques such as nucleic acid microarrays or enzyme-linked immunosorbent assays (ELISAs), is an important criterion for new biosensors. Here, we describe the successful detection of a 35-base, single-strand nucleic acid target by Hall-based magnetic transduction as a mimic for pathogenic DNA target detection. The detection platform has low background, large signal amplification following target binding and can discriminate a single, 350 nm superparamagnetic bead labeled with DNA. Detection of the target sequence was demonstrated at 364 pM (<2 target DNA strands per bead) target DNA in the presence of 36 μM nontarget (noncomplementary) DNA (<10 ppm target DNA) using optical microscopy detection on a GaAs Hall mimic. The use of Hall magnetometers as magnetic transduction biosensors holds promise for multiplexing applications that can greatly improve point-of-care (POC) diagnostics and subsequent medical care.
authors.affiliation: Department of Chemistry and Biochemistry, The Florida State University, Tallahassee, FL 32306-4390, USA.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Hira
authors.forename: Khaled
authors.initials: K
authors.lastname: Aledealat
authors.forename: Kan-Sheng
authors.initials: KS
authors.lastname: Chen
authors.forename: Mark
authors.initials: M
authors.lastname: Field
authors.forename: Gerard J
authors.initials: GJ
authors.lastname: Sullivan
authors.forename: P Bryant
authors.initials: PB
authors.lastname: Chase
authors.forename: Peng
authors.initials: P
authors.lastname: Xiong
authors.forename: Stephan
authors.initials: S
authors.lastname: von Molnár
authors.forename: Geoffrey F
authors.initials: GF
authors.lastname: Strouse
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D015342:DNA Probes / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000032:analysis* / Q000737:chemistry; D004867:Equipment Design; D052203:Ferrosoferric Oxide / Q000737:chemistry; D057230:Limit of Detection; D060306:Magnetometry / Q000295:instrumentation*; D008853:Microscopy / Q000295:instrumentation / Q000379:methods; D008863:Microspheres; D055616:Microtechnology / Q000295:instrumentation; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation* / Q000379:methods*
chemical_list: D015342:DNA Probes; D004277:DNA, Single-Stranded; D052203:Ferrosoferric Oxide