Impedimetric sensor for toxigenic Penicilliumsclerotigenum detection in yam based on magnetite-poly(allylamine hydrochloride) composite

• Published in: Journal of colloid and interface science Vol. 396; pp. 258 - 263
• Main Authors: Silva, Gilcelia J.L., Andrade, Cesar A.S., Oliveira, Idjane S., de Melo, Celso P., Oliveira, Maria D.L.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 15.04.2013
• Subjects: binding sites; biocompatibility; Biosensor; biosensors; Composite; dielectric spectroscopy; DNA; electrical resistance; exposure duration; food contamination; fungi; genome; Impedance spectroscopy; Magnetic nanoparticles; magnetite; nucleic acid hybridization; nucleotides; Penicillium; Penicillium sclerotigenum; yams; Penicillium sclerotigenum; Impedance spectroscopy; Composite; Biosensor; Magnetic nanoparticles
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2013.01.023

[Display omitted] ► A DNA biosensor for Penicillium sclerotigenum detection was obtained. ► The biosensor requires only small volumes and low concentrations of the analyte. ► EIS was successfully applied for detection of DNA sequences of toxigenic fungi. ► The sensor showed good specificity and sensitivity. We describe a new DNA biosensor for the detection of toxigenic Penicillium sclerotigenum in pure culture or infected yams. The P. sclerotigenum detection takes place on a self-assembled monolayer of a (magnetite)/(poly(allylamine hydrochloride)) (Fe3O4–PAH) composite that serves as an anchoring layer for the DNA hybridization interaction. Electrical impedance spectroscopy (EIS) was used to evaluate and quantify the hybridization degree. The Fe3O4–PAH composite is a good platform for the immobilization of biomolecules, due to the presence of many possible binding sites for nucleotides and to its large surface-to-volume ratio and good biocompatibility. The biosensor was capable of not only qualitatively detecting the presence of the fungus genome at low concentrations, but also shown a good quantitative impedimetric response its electrical resistance was monitored along the time of exposure. A Fe3O4–PAH-probe biosensor would require only small volumes and low concentrations of the analyte when used, for instance, in detecting P. sclerotigenum contamination of food, besides presenting many comparative advantages, such as selectivity, specificity and reproducibility, relative to alternative techniques.