Characterization and modelling of differential sensitivity of nanoribbon-based pH-sensors

Abstract

We report accurate characterization, modelling and simulation of SOI nanoribbon-based pH sensors and we compare operation in air (dry) and electrolyte (wet) environments. We find remarkably different current density distributions and geometry scaling rules, but similar series resistances and active trap state densities in the two configurations. Calibrated TCAD based simulations implementing an original approach to model the site-binding harge, and in good agreement with experiments, provide the necessary insights to interpret the non trivial dependence of the threshold voltage and current sensitivity on pH

Calculation of surface potentials at the silica–water interface using molecular dynamics: Challenges and opportunities

“…This model is not intended to supersede continuum models for this application, indeed quantitative accuracy of the surface charge to surface potential is highly sensitive to the accuracy of the empirical relationship used for pH to surface charge density (as is also often the case when parameterising site-binding models for predicting pHpotential response), and to the definition of the surface plane. This model, however, presents three key advantages over conventional continuum models such as site-binding models 63,82,83) and the Grahame equation for biosensing. [24][25][26] Firstly, complex biomolecular systems can be incorporated with relative ease and without requirement for system specific parametrisation.…”