The mediatorless biosensors are advantageous over the mediator-based biosensors because of the simplicity in their application and modelling. The biosensors with the direct electron transfer have higher selectivity and are less prone to the interfering reactions [11�C13]. One of the main obstacles in the development of the mediatorless biosensors is that only Tubacin microtubule few enzymes can support the direct electron transfer [14].Since the discovery of carbon nanotubes [15] they have been used in various applications. Due to their unique structural and electric properties, carbon nanotubes (CNT) have been used to build highly sensitive biosensors [16�C18]. Recently, an innovative approach in the design of biosensors with the CNT mesh deposited on the polycarbonate perforated membrane has been proposed [19], and a novel family of mediated biosensors acceptable for detection of wide range of carbohydrates have been designed [20].
The use of CNTs opens an opportunity for the direct electron transfer between the enzyme and the electrode [21]. The application of glucose dehydrogenase and CNTs permitted to build mediator free glucose biosensor [21].The development and optimization Inhibitors,Modulators,Libraries of new biosensors require a high number of experiments. Mathematical modelling is rather often used in order to decrease the number of physical experiments by replacing them with mathematical simulations [22,23]. Starting from 1970s, mathematical modelling has been proved as an effective tool to study and optimize analytical characteristics of actual biosensors [24�C26].
A comprehensive review on modelling of the amperometric biosensors has been presented by Schulmeister Inhibitors,Modulators,Libraries [27] and more recently by Baronas et al. [28].A CNT-based biosensor was mathematically modelled by Lyons [29,30]. The one-dimensional-in-space boundary value problem describing the transport and the kinetics of the substrate and the mediator in the two compartment domain was solved analytically, assuming steady state conditions. Practical biosensors are usually built covering them with outer porous or perforated membranes [3,6,19]. The mathematical model for the mediated biosensor with the CNT electrode deposited on the perforated membrane was proposed recently [31].This paper presents a mathematical model of the mediatorless amperometric biosensor based on the enzyme-loaded CNT electrode deposited on the outer perforated membrane.
The proposed model describes the unmediated operation of the biosensor having the geometrical structure similar to that Inhibitors,Modulators,Libraries of the already modelled Inhibitors,Modulators,Libraries mediated biosensor [19,31]. The model is based on nonlinear non-stationary reaction-diffusion AV-951 equations. The new model is described in a one-dimensional-in-space selleck bio domain and comprises four layers (compartments): a layer of enzyme solution entrapped on a terylene membrane, a layer of the single walled carbon nanotubes, a perforated membrane and an outer diffusion layer.