title: High sensitivity biosensor measurement based on synchronous detection.
abstract: The principle of synchronous detection (SD) has been applied to biosensor measurement. SD principle achieves significant increases in the signal to noise ratio, limit of detection and overall measurement robustness. Application of SD in biosensor measurement improves the analysis of the response and avoids the influence of interference/noise produced by stirring, electromagnetic effects and influence of parasitic currents. SD also enables the decomposition of signal to stimulation response and phenomena with long time of response. Second-order phenomena are identifiable in the signal. Linear statistical model was used to develop software for identification of the stimulation signal in the output current. SD was applied to the response signal of a Photosystem II complex (PSII) biosensor. PSII response to light stimulation follows first order kinetics. The inhibition kinetics of PSII has been studied. Kinetic constants of herbicide binding to PSII depend linearly on herbicide concentration and enable measurement of its concentration at low concentrations (linear range for diuron is 10⁻⁶ to 10⁻⁴ mM).
authors.affiliation: BVT Technologies a.s. Hudcova 78, CZ-612 00 Brno, Czech Republic. tab@bvt.cz
authors.forename: J
authors.initials: J
authors.lastname: Krejci
authors.forename: V
authors.initials: V
authors.lastname: Ondruch
authors.forename: J
authors.initials: J
authors.lastname: Maly
authors.forename: M
authors.initials: M
authors.lastname: Stofik
authors.forename: D
authors.initials: D
authors.lastname: Krejcova
authors.forename: H
authors.initials: H
authors.lastname: Vranova
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004800:Enzymes, Immobilized / Q000037:antagonists & inhibitors / Q000378:metabolism; D007700:Kinetics; D045332:Photosystem II Protein Complex / Q000037:antagonists & inhibitors / Q000378:metabolism; D046940:Synechococcus / Q000201:enzymology; D013997:Time Factors
chemical_list: D004791:Enzyme Inhibitors; D004800:Enzymes, Immobilized; D045332:Photosystem II Protein Complex