▎ 摘　　要

The alteration of electronic properties in chemically modified graphene can be utilized for chemical and biosensing applications. Thus, it is essential to understand how the alteration of density of states and conductance spectra of functionalized zigzag and armchair graphene nanoribbon (GNR) affects its sensitivity. In this aspect, the current-voltage characteristics of GNR based sensors are modeled using the non-equilibrium Green's function method. Our findings show that the presence of chemical moiety at one edge of the zigzag GNR structure opens the bandgap that reduces the current conduction and enhances the sensitivity for detection. However, double edge functionalization restores the semi-metallic character of the zigzag ribbon that reduces the sensitivity. Both single and double edge atomic substitution in armchair ribbon makes it n-type, which shows the alteration in current conduction for detecting the presence of the chemical species. We further found that increasing the width of the ribbon decreases the device sensitivity while it increases for the double edge substituted zigzag structure. The study thus provides essential information and insights into utilizing and operating different edge structures of graphene based sensors for effective detection of chemical and biomolecular species.