Programming a nonvolatile memory-like sensor for KRAS gene sensing and signal enhancement

A programmable field effect-based electrolyte-insulator-semiconductor (EIS) sensor constructed with a nonvolatile memory-like structure is proposed for KRAS gene DNA hybridization detection. This programmable EIS structure was fabricated with silicon oxide (SiO₂)/silicon nitride (Si₃N₄)/silicon oxide on a p-type silicon wafer, namely electrolyte-oxide-nitride-oxide-Si (EONOS). In this research, voltage stress programming from 4 to 20V was applied to trigger holes confinement in the nitride-trapping layer that, consequently, enhances the DNA attachment onto the sensing surface due to additional electrostatic interaction. Not solely resulting from the higher DNA load, the programming may affect the orientation of the DNA that finally contributes to the change in capacitance. Findings have shown that a higher voltage program is able to increase the total capacitance and results in ~3.5- and ~5.5-times higher sensitivities for a series of concentrations for complementary DNA and wild type versus mutant DNA hybridization detection, respectively. Overall, it has been proven that the voltage program on the nonvolatile memory-like structure of EONOS is a notable candidate for genosensor development, scoping the diagnosis of a single nucleotide polymorphism (SNP)-related disease.