title: DNA-based amplified electrical bio-barcode assay for one-pot detection of two target DNAs.
abstract: A sensitive label-free bio-barcode assay provided a PCR-free method for quantitative detection of two nucleic acid targets (HTLV-I and HTLV-II) simultaneously. This DNA biosensor was fabricated with two-component oligonucleotide-modified gold nanoparticles (AuNPs) and two-component oligonucleotide-modified magnetic beads (MBs), which can sandwich a specific target. After liberating the adsorbed thiolated barcode DNA strands (poly A and poly G) from the AuNPs surface with dithiothreitol (DTT) and acidic dipurinization, the electrochemical measurements were directly performed based on the redox activity of guanine (G) and adenine (A) nucleobases. Under the optimal assembling and detection conditions, a good linearity for simultaneous detection was obtained in the range from 4.4x10(-11) to 2.0x10(-9) M, and the detection limit (3sigma) was estimated to be 1.71x10(-12) M for T(1)-DNA and 1.55x10(-12) M for T(2)-DNA.
authors.affiliation: Key Laboratory of Eco-chemical Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China.
authors.forename: Xiaoru
authors.initials: X
authors.lastname: Zhang
authors.forename: Haoran
authors.initials: H
authors.lastname: Su
authors.forename: Sai
authors.initials: S
authors.lastname: Bi
authors.forename: Shuguo
authors.initials: S
authors.lastname: Li
authors.forename: Shusheng
authors.initials: S
authors.lastname: Zhang
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D015169:Colony Count, Microbial / Q000295:instrumentation; D004279:DNA, Viral / Q000032:analysis* / Q000737:chemistry / Q000235:genetics*; D004563:Electrochemistry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D018390:Gene Targeting / Q000295:instrumentation; D015368:Human T-lymphotropic virus 1 / Q000235:genetics / Q000302:isolation & purification*; D015367:Human T-lymphotropic virus 2 / Q000235:genetics / Q000302:isolation & purification*; D021141:Nucleic Acid Amplification Techniques / Q000295:instrumentation*; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D004279:DNA, Viral