title: Harnessing aptamers for electrochemical detection of endotoxin.
abstract: Lipopolysaccharide (LPS), also known as endotoxin, triggers a fatal septic shock; therefore, fast and accurate detection of LPS from a complex milieu is of primary importance. Several LPS affinity binders have been reported so far but few of them have proved their efficacy in developing electrochemical sensors capable of selectively detecting LPS from crude biological liquors. In this study, we identified 10 different single-stranded DNA aptamers showing specific affinity to LPS with dissociation constants (K(d)) in the nanomolar range using a NECEEM-based non-SELEX method. Based on the sequence and secondary structure analysis of the LPS binding aptamers, an aptamer exhibiting the highest affinity to LPS (i.e., B2) was selected to construct an impedance biosensor on a gold surface. The developed electrochemical aptasensor showed excellent sensitivity and specificity in the linear detection range from 0.01 to 1 ng/mL of LPS with significantly reduced detection time compared with the traditional Limulus amoebocyte lysate (LAL) assay.
authors.affiliation: School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Sung-Eun
authors.initials: SE
authors.lastname: Kim
authors.forename: Wenqiong
authors.initials: W
authors.lastname: Su
authors.forename: MiSuk
authors.initials: M
authors.lastname: Cho
authors.forename: Youngkwan
authors.initials: Y
authors.lastname: Lee
authors.forename: Woo-Seok
authors.initials: WS
authors.lastname: Choe
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000235:genetics; D001483:Base Sequence; D015374:Biosensing Techniques; D017097:Electric Impedance; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D004583:Electrons; D019075:Electrophoresis, Capillary; D015723:Gene Library; D006046:Gold / Q000737:chemistry; D007700:Kinetics; D008070:Lipopolysaccharides / Q000032:analysis*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation
chemical_list: D052157:Aptamers, Nucleotide; D008070:Lipopolysaccharides; D006046:Gold