Mesoporous Titania-Coated Biosensor and FEM Model for Highly Sensitive Detection of Low Molecular Weight Targets

This paper presents the interest of a highly sensitive biosensor coated with a TiO2 mesoporous film as a sensitive layer. The main novelty is related to the modeling of the device and simulation by using the finite element method with a COMSOL multiphysics software as a good way to take into account the physical properties of porous 3-D layers. The strategy of using such Love wave devices, with 3-D porous layers, offering further easy functionalization, aims not only to increase the amount of targets caught on the sensor surface but also to enhance the detection mechanism by a higher perturbation of the Love wave acoustic energy, which could be trapped inside the 3-D sensitive layer. First, as a proof of concept, experimental devices with a 3-D titania mesoporous layer were realized, and they have shown a good agreement with simulated results. Furthermore, experimental tests with several Newtonian liquids are investigated, in a range of viscosities from 1 to 7 cP, which are typical of those that concern our biochemical applications. The sensitivity with a 300 nm thick porous sensing layer was ten times that of the bare device, with interesting dynamical issues to be further studied, giving rise to the great potentialities of such architectures for biological detection of low weight biochemical targets.