title: Urease-gelatin interdigitated microelectrodes for the conductometric determination of protease activity.
abstract: Conductometric microbiosensors for the determination of trypsin were elaborated via the modification of microfabricated interdigitated gold electrodes by a cross-linked urease/BSA coating covered by a gelatin film. The resulting microelectrodes were exposed to different trypsin concentrations ranging from 100 pg/mL to 1mg/mL (1 mU/mL to 10,000 U/mL) for selective proteolytic degradation of the gelatin film. Then, the conductometric response of the microbiosensors to urea (33 microM) was recorded as a function of the trypsin concentration, the gelatin amount (8-80 ng) and the incubation time (40s, 100 min). The optimum incubation time for each trypsin concentration was determined leading to a detection limit of 100 pg/mL (1 mU/mL). In these optimized conditions, the proof of concept of this sensitive, disposable, low-cost and label-free trypsin biosensors based on a conductometric transducer was demonstrated for the first time.
authors.affiliation: Laboratoire des Sciences Analytiques, UMR CNRS 5180, Université Claude Bernard Lyon 1, 69622 Villeurbanne Cedex, France.
authors.forename: Rodica E
authors.initials: RE
authors.lastname: Ionescu
authors.forename: Chrystelle
authors.initials: C
authors.lastname: Fillit
authors.forename: Nicole
authors.initials: N
authors.lastname: Jaffrezic-Renault
authors.forename: Serge
authors.initials: S
authors.lastname: Cosnier
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D003217:Conductometry / Q000295:instrumentation*; D005780:Gelatin / Q000737:chemistry*; D008839:Microelectrodes; D015203:Reproducibility of Results; D014357:Trypsin / Q000378:metabolism*; D014510:Urease / Q000737:chemistry*
chemical_list: C015233:gelatin film; D005780:Gelatin; D014357:Trypsin; D014510:Urease