SIMULATION OF A SILICON NANOWIRE FET BIOSENSOR FOR DETECTING BIOTIN/STREPTAVIDIN BINDING

Silicon nanowire field-effect transistor (SiNW FET) biosensors have recently been demonstrated experimentally for direct, label free, high sensitive, high selective and real time detection of DNA and proteins at very low concentration. Among these experiments, the detection of biotin/streptavidin binding is of special interest since the biotin/streptavidin system exhibits one of the strongest noncovalent biological interactions known in nature. Thus, biotin/streptavidin system is widely demonstrated as a model system to study biorecognition between proteins and other biomolecules. Despite these promising experimental results and their enormous potential, it is somewhat surprising that the fundamental mechanism of electrical sensing of biomolecules and the design principles of SiNW FET biosensor remain poorly understood. In this work, a comprehensive modeling theory and simulation approach is presented to account for the underlying detection mechanism of biotin/Streptavidin binding using SiNW FET biosensor. The influence of parameters like the dimension of the SiNW, the doping of the SiNW, and surrounding environment (the ions concentration in the solvent) are investigated for the performance optimization of the SiNW FET biosensor. The preliminary simulation results indicate that the optimal sensor performance can be ensured by careful optimization of its parameters and it is feasible to detect binding of single streptavidin molecule when optimal parameters are chosen