title: Development of a real-time capacitive biosensor for cyclic cyanotoxic peptides based on Adda-specific antibodies.
abstract: The harmful effects of cyanotoxins in surface waters have led to increasing demands for accurate early warning methods. This study proposes a capacitive immunosensor for broad-spectrum detection of the group of toxic cyclic peptides called microcystins (∼80 congeners) at very low concentration levels. The novel analytical platform offers significant advances compared to the existing methods. Monoclonal antibodies (mAbs, clone AD4G2) that recognize a common element of microcystins were used to construct the biosensing layer. Initially, a stable insulating anchor layer for the mAbs was made by electropolymerization of tyramine onto a gold electrode surface, with subsequent incorporation of gold nanoparticles (AuNPs) on the glutaraldehyde (5%) activated polytyramine surface. The biosensor responded linearly to microcystin concentrations from 1×10(-13)M to 1×10(-10)M MC-LR standard with a limit of detection of 2.1×10(-14)M. The stability of the biosensor was evaluated by repeated measurements of the antigen and by determining the capacitance change relative to the original response, which decreased below 90% after the 30th cycle.
authors.affiliation: Department of Biotechnology, Lund University, Box 124, 22100 Lund, Sweden.
authors.forename: Lesedi
authors.initials: L
authors.lastname: Lebogang
authors.affiliation: Department of Biotechnology, Lund University, Box 124, 22100 Lund, Sweden. Electronic address: martin.hedstrom@biotek.lu.se.
authors.forename: Martin
authors.initials: M
authors.lastname: Hedström
authors.affiliation: Department of Biotechnology, Lund University, Box 124, 22100 Lund, Sweden; CapSenze HB, Annersbergs gård 5520, 26021 Billeberga, Sweden.
authors.forename: Bo
authors.initials: B
authors.lastname: Mattiasson
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology*; D001427:Bacterial Toxins / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D000458:Cyanobacteria / Q000378:metabolism*; D025802:Electric Capacitance; D055664:Electrochemical Techniques; D052998:Microcystins / Q000737:chemistry*; D015394:Molecular Structure; D012680:Sensitivity and Specificity
chemical_list: D000906:Antibodies; D001427:Bacterial Toxins; D052998:Microcystins
keywords: Adda-specific antibodies; Capacitive; Cyclic cyanotoxins; Electropolymerization; Gold nanoparticles