title: Detection of the carcinogenic water pollutant benzo[a]pyrene with an electro-switchable biosurface.
abstract: The toxic nature of polycyclic aromatic hydrocarbons (PAHs), in particular benzo[a]pyrene (B[a]P), neccessitates the monitoring of PAH contamination levels in food and the environment. Here we introduce an indirect immunoassay format using electro-switchable biosurfaces (ESB) for the detection of B[a]P in water. The association of anti-B[a]P antibodies to microelectrodes is analyzed in real-time by measuring changes in the oscillation dynamics of DNA nanolever probes, which are driven to switch their orientations by high-frequency electrical actuation. From the association kinetics, the active concentration of anti-B[a]P, and hence the B[a]P contamination of the sample, can be determined with picomolar sensitivity. The detection limit of the assay improves with measurement time because increasingly accurate analyses of the binding kinetics become possible. It is demonstrated that an exceedance of the permissible 10 ng/L (40 pM) limit for B[a]P is detectable in an unprecedented short assay time (<1 h), using a simple three-step workflow involving minimal sample preparation. The reproducibility was satisfying with standard deviations below 5%. Further, the utility of the assay for practical applications is exemplified by analyzing a river water sample.
authors.affiliation: †Technische Universität München, 85748 Garching, Germany.
authors.forename: Gregor
authors.initials: G
authors.lastname: Lux
authors.affiliation: †Technische Universität München, 85748 Garching, Germany.|‡Dynamic Biosensors GmbH, Lochhamer Strasse 15, 82152 Martinsried/Planegg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Langer
authors.affiliation: §Institute of Hydrochemistry and Chair of Analytical Chemistry, Technische Universität München, Marchioninistrasse 17, 81377 München, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Pschenitza
authors.affiliation: §Institute of Hydrochemistry and Chair of Analytical Chemistry, Technische Universität München, Marchioninistrasse 17, 81377 München, Germany.
authors.forename: Xaver
authors.initials: X
authors.lastname: Karsunke
authors.affiliation: ‡Dynamic Biosensors GmbH, Lochhamer Strasse 15, 82152 Martinsried/Planegg, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Strasser
authors.affiliation: §Institute of Hydrochemistry and Chair of Analytical Chemistry, Technische Universität München, Marchioninistrasse 17, 81377 München, Germany.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Niessner
authors.affiliation: §Institute of Hydrochemistry and Chair of Analytical Chemistry, Technische Universität München, Marchioninistrasse 17, 81377 München, Germany.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Knopp
authors.affiliation: ‡Dynamic Biosensors GmbH, Lochhamer Strasse 15, 82152 Martinsried/Planegg, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Rant
mesh_terms: D000906:Antibodies / Q000276:immunology; D001564:Benzo(a)pyrene / Q000032:analysis* / Q000737:chemistry; D002273:Carcinogens / Q000032:analysis* / Q000737:chemistry; D015342:DNA Probes / Q000032:analysis / Q000378:metabolism; D004583:Electrons; D007118:Immunoassay; D007700:Kinetics; D008839:Microelectrodes; D045483:Rivers / Q000737:chemistry; D013499:Surface Properties; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry / Q000276:immunology
chemical_list: D000906:Antibodies; D002273:Carcinogens; D015342:DNA Probes; D014874:Water Pollutants, Chemical; D001564:Benzo(a)pyrene