title: Sensitive and direct electrochemical detection of double-stranded DNA utilizing alkaline phosphatase-labelled zinc finger proteins.
abstract: Direct detection of double-stranded DNA (dsDNA) using zinc finger proteins (ZFPs) is of great importance in biomedical applications such as identifying pathogens and circulating DNAs. However, its sensitivity is still not sufficiently high because limited signalling labels can be conjugated or fused. Herein, we report sensitive and direct detection of dsDNA using (i) alkaline phosphatase (ALP) as a fast catalytic label conjugated to ZFPs along with (ii) electrochemical measurement of an ALP product (l-ascorbic acid) at the indium-tin oxide electrode with a high signal-to-background ratio. ALP is simply conjugated to a ZFP through lysine residues in a ZFP purification tag, a maltose binding protein (MBP). Sandwich-type electrochemical detection of dsDNA allows a detection limit of ca. 100 fM without using DNA amplification.
authors.affiliation: Department of Chemistry and Chemistry Institute of Functional Materials, Pusan National University, Busan 609-735, Korea. hyang@pusan.ac.kr.
authors.forename: Soodong
authors.initials: S
authors.lastname: Noh
authors.forename: Dat Thinh
authors.initials: DT
authors.lastname: Ha
authors.forename: Haesik
authors.initials: H
authors.lastname: Yang
authors.forename: Moon-Soo
authors.initials: MS
authors.lastname: Kim
mesh_terms: D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D001710:Biotin / Q000378:metabolism; D004247:DNA / Q000032:analysis* / Q000737:chemistry / Q000235:genetics; D004563:Electrochemistry; D057230:Limit of Detection; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D015345:Oligonucleotide Probes / Q000737:chemistry; D016335:Zinc Fingers
chemical_list: D015345:Oligonucleotide Probes; D001710:Biotin; D004247:DNA