Abstract:
Matl~einatical model that can describe the transient and steady state responses of glucose biosensor was proposed. An amperometric enzyme electrode, modified by entrapmcnt of glucose oxidase in a non-conducting polymer (1,3-DAB) film was coilstructed and used to determine the concentrations of Hz02 and glucose solutions. The results of the model of glucose biosensor were fitted to the experiincntal rcsults in order to determine the effective diffusion coefficients of 1-1202 and glucose in non-conducting polymer (1,3-DAB) film. The effective diffusion coeficient of Hz02 was evaluated to 1.89~10-" m2/s. The effective diffusion coefficients of glucose and 02 were approximated to be 1.21 x 10-'and 1.89~ 10-I m2/s, respectively. The effective diffusion coefficient of H202 with enzyinc loading was found to bc about 2.53 times of that without enzyme loading. Mathematical modcl that can describe the transient and steady state of multi-enzyme oublc laycr biosensor was proposed and its solutions were obtaincd numerically. Thc incthod of ol-thogonal collocatioil was used to transforin the model, which was a sct of partial differential equations, to a sct of ordinary differcntial cquations (ODES). Thc cffccts of iilin tllickncss (LI), enzyme activity of INV (RnlaX,,) as wcll as enzyine activity or MUT (Rmax,2) on elcctrodc rcsponscs were studied. By varying the thickness of polymcr film, a inaxiinuin stcady-state electrode current could be fo~ind. Thc siinulation results also showed that thcre were a certain amount of JNV aid MUT in thc iilin that could give a inaxiinuin clectrodc currcnt. Moreover, it is noticcd that Rmax,2 was less scnsitivc to transient and stcady-state responscs than R,ll,x,I. The matl~einatical inodel proposed in this work could be used in the design of a multi-enzyme doublc-layer sucrose biosensor.