An amperometric biosensor based on acetylcholinesterase (AChE) immobilized in gelatin was used to develop an assay for the organophosphate paraoxon. The more traditional manner employing preincubation was used for comparison between measurement procedures, although the aim of the study was to examine the performance of the biosensor for real time monitoring of organophosphates. The biosensor was immersed in a reaction chamber and paraoxon was injected inside. We were able to detect 200 pg of paraoxon within one minute or 2.5 ppb when the biosensor was preincubed in the sample solution for 15 minutes. The practical impact and expectations are discussed.

• Keywords
• Organophosphate, acetylcholinesterase, assay, biosensor, electrochemical, paraoxon,
• Publication type
• Journal Article MeSH

Piezoelectric biosensor was used for diagnosis of infection by Francisellatularensis subsp. holarctica in European brown hares. Two kinds of experiments wereperformed in this study. First, sera from experimentally infected European brown hares(Lepus europaeus) were assayed by piezoelectric biosensor and the seventh day postinfection was found as the first one when statistically significant diagnosis of tularemia waspossible; all other sera collected from hares later than on day 7 following the infection werefound tularemia positive. Typing to classify the field strain of F. tularensis used for theexperimental infection was confirmed by proteome study. Second, sera from 35 Europeanbrown hare specimens sampled at hunting grounds and tested as tularemia positive by slowagglutination allowed diagnosis of tularemia by the piezoelectric biosensor. All these sera ofnaturally infected hares were found as tularemia positive, too. Efficacy of the piezoelectricbiosensor for the serological diagnosis of tularemia is discussed.

• Keywords
• Francisella tularensis, agglutination test, experimental and natural infection, immunosensor, reservoir host, serology, zoonosis,
• Publication type
• Journal Article MeSH