title: Capacitive biosensor for detection of endotoxin.
abstract: A capacitive biosensor for the detection of bacterial endotoxin has been developed. Endotoxin-neutralizing protein derived from American horseshoe crab was immobilized to a self-assembled thiol layer on a biosensor transducer (Au). Upon injection of a sample containing endotoxin, a decrease in the observed capacitive signal was registered. Endotoxin could be determined under optimum conditions with a detection limit of 1.0 x 10(-13) M and linearity ranging from 1.0 x 10(-13) to 1.0 x 10(-10) M. Good agreement was achieved when applying endotoxin preparations purified from an Escherichia coli cultivation to the capacitive biosensor system, utilizing the conventional method for quantitative endotoxin determination, the Limulus amebocyte lysate test as a reference. The capacitive biosensor method was statistically tested with the Wilcoxon signed rank test, which proved the system is acceptable for the quantitative analysis of bacterial endotoxin (P<0.05).
authors.affiliation: Department of Biotechnology, Center for Chemistry and Chemical Engineering, Lund University, Box 124, 221 00, Lund, Sweden.
authors.forename: Warakorn
authors.initials: W
authors.lastname: Limbut
authors.forename: Martin
authors.initials: M
authors.lastname: Hedström
authors.forename: Panote
authors.initials: P
authors.lastname: Thavarungkul
authors.forename: Proespichaya
authors.initials: P
authors.lastname: Kanatharana
authors.forename: Bo
authors.initials: B
authors.lastname: Mattiasson
mesh_terms: D015374:Biosensing Techniques; D004566:Electrodes; D004731:Endotoxins / Q000032:analysis*; D004926:Escherichia coli / Q000378:metabolism; D006046:Gold; D012680:Sensitivity and Specificity
chemical_list: D004731:Endotoxins; D006046:Gold