The mathematical model and the numerical solution were validated by experimental data. The obtained Tubacin mw agreement between Inhibitors,Modulators,Libraries the simulation results and the experimental data was admissible at different substrate concentrations. The biosensor response and sensitivity were numerically investigated by changing the model parameters with a special emphasis on the mediatorless transfer of the electrons in the layer of the enzyme-loaded CNTs.2.?Principal Structure of the BiosensorThe investigated biosensor has the layered structure and is composed of different materials and sizes according to [19]. The active surface of the biosensor is built by binding the mesh of the single wall carbon nanotubes to the perforated membrane. Some of the nanotubes are sinked into the holes of the membrane during the preparation procedure.
Then CNTs were pre-oxidized enzymatically using laccase from Basidiomycete Lac. After this procedure, the layer of CNT was throughly washed with distilled water up to total clearing of laccase and covered by the layer of the enzyme. The changeable enzyme layer of proposed CNT-based biosensor Inhibitors,Modulators,Libraries was designed by immobilization of soluble type of pyrroloquinoline quinone dependent glucose dehydrogenase from Acinetobacter calcoaceticus L.M.D. 79.41 to the semi-permeable membrane of terylene.All electrochemical experiments were performed using a conventional three-electrode system containing a planar CNT electrode as a working electrode, a platinum wire as a counter electrode and an Ag/AgCl in saturated KCl as a reference electrode. The default buffer was 0.05 M acetate buffer (pH 6.
0) containing 1 mM Ca2+. Steady state currents of the biosensors were recorded at 0.4 V using a polarographic analyzer ��PARSTAT 2273�� (Princeton Applied Research, USA). Principal structure of the considered biosensor is shown in Figure 1.Figure Inhibitors,Modulators,Libraries 1.Principal structure of the active surface of the biosensor. The Inhibitors,Modulators,Libraries figure is not to scale.Enzymatic reaction is employed in the biosensor to selectively detect the substrate (S) in the target analyte. The enzymatic reaction takes place in the regions of the biosensor filled with the enzyme,Eox+S��k1Ered+P,(1)where k1 is a constant of the enzymatic reaction rate. In the reaction, the substrate S reacts with the oxidized Cilengitide form of the enzyme (Eox) and reduces it (Ered) producing the product P.
The latter is considered as not impacting the processes in the biosensor and therefore is omitted in the following model.The output current of the biosensor is generated due to the direct enzyme oxidation taking place in the layer of the carbon nanotubes,Ered��k2Eox+nee?,(2)where k2 is a constant read more of the electrochemical reaction rate and ne is the number of electrons released in one reaction event. The enzyme Ered is re-oxidized in the Reaction (2) releasing electrons that are collected by the CNT electrode.3.