Development of Carbon Nanotube Based Biosensors Model for Detection of Single-Nucleotide Polymorphism

Carbon nanotube network (CNT) based DNA nanosensors have outstanding potential as selective detectors of DNA immobilization and hybridization for genetic researchers to understand the progression of disease, develop diagnostics and therapeutics. In this paper, a model is developed in recognition of target DNA sequences for nanosensors based on carbon nanotube field-effect transistors (CNTFETs). We start by modeling the H63D single-nucleotide polymorphism (SNP) discrimination in the HFE gene, which is responsible for hereditary hemochromatosis, as a function of CNT conductance. Moreover, two fitting parameters of beta and gamma are obtained from comparison of experimental and modeling data of CNT conductance behavior in CNTFETs devices. To continue, a CNT conductance modeling is proposed for electrical detection of DNA hybridization, where the DNA concentration is considered as a function of gate voltage. Finally the proposed models for wild type-wild type and wild type-mutant DNA combinations are compared with experimental data and a good agreement is reported.