Simulation tool coupling nonlinear electrophoresis and reaction kinetics for design and optimization of biosensors

We present the development, formulation, validation, and demonstration of a fast, generic, and open source simulation tool, which integrates nonlinear electromigration with multispecies nonequilibrium kinetic reactions. The code is particularly useful for the design and optimization of new electrophoresis- based bioanlaytical assays, in which electrophoretic transport, separation, or focusing control analyte spatial concentration and subsequent reactions. By decoupling the kinetics solver from the electric field solver, we demonstrate an order of magnitude improvement in total simulation time for a series of 100 reaction simulations using a shared background electric field. The code can efficiently handle complex electrophoretic setups coupling sharp electric field gradients with bulk reactions, surface reactions, and competing reactions. For example, we demonstrate the use of the code for investigating accelerated reactions using isotachophoresis (ITP), revealing new regimes of operation which in turn enable significant improvement of the signal-to-noise ratio of ITP-based genotypic assays. The user can define arbitrary initial conditions and reaction rules, and we believe it will be a valuable tool for the design of novel bioanalytical assays. We will offer the code as open source, and it will be available for free download at http://microfluidics.technion.ac.il.