A DNA Biosensor Based Interface States of a Metal-Insulator-Semiconductor Diode for Biotechnology Applications

We studied how a DNA sensor based on the interface states of a conventional metal-insulator-semiconductor diode can be prepared for biotechnology applications. For this purpose, the p-type silicon/metal diodes were prepared using $SiO_2$ and DNA layers. The obtained results were analyzed and compared with interfaces of DNA and $SiO_2$. It is seen that the ideality factor (1.82) of the $Al//p-Si//SiO_2//DNA//Ag$ diode is lower than that (3.31) of the $Al//p-Si//SiO_2//Ag$ diode. This indicates that the electronic performance of DNA/Si junction was better than that of $SiO_2//Si$ junction. The interface states of the $Al//p-Si//SiO_2//DNA//Ag$ and $Al//p-Si//SiO_2//Ag$ junctions were analyzed by conductance technique. The obtained D_{it} values indicate that the DNA layer is an effective parameter to control the interface states of the conventional Si based on metal/semiconductor contacts. Results exhibited that DNA based metal-insulator-semiconductor diode could be used as DNA sensor for biotechnology applications.